Safe Haskell	None
Language	Haskell2010

Verset

Contents

Basic functions
Basic algebraic types
Text types
- Char and String
- String conversion
Container types
- Map and Set (Ordered)
- Seq
Numeric types
Numeric type classes
Read and Show
- Show
- Read
Equality and ordering
- Eq
- Ord
- Enum
- Bounded
Algebraic type classes
Effects and monad transformers
Generic type classes
Type level
IO
- Console
Error handling and debugging
Time
Custom

Synopsis

(&) :: a -> (a -> b) -> b
($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
const :: a -> b -> a
fix :: (a -> a) -> a
flip :: (a -> b -> c) -> b -> a -> c
on :: (b -> b -> c) -> (a -> b) -> a -> a -> c
($!) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
seq :: forall (r :: RuntimeRep) a (b :: TYPE r). a -> b -> b
data Void
(&&) :: Bool -> Bool -> Bool
(||) :: Bool -> Bool -> Bool
bool :: a -> a -> Bool -> a
data Bool
- = False
- | True
not :: Bool -> Bool
otherwise :: Bool
(?:) :: Maybe a -> a -> a
catMaybes :: [Maybe a] -> [a]
fromMaybe :: a -> Maybe a -> a
isJust :: Maybe a -> Bool
isNothing :: Maybe a -> Bool
mapMaybe :: (a -> Maybe b) -> [a] -> [b]
maybe :: b -> (a -> b) -> Maybe a -> b
data Maybe a
- = Nothing
- | Just a
break :: (a -> Bool) -> [a] -> ([a], [a])
drop :: Int -> [a] -> [a]
dropWhile :: (a -> Bool) -> [a] -> [a]
dropWhileEnd :: (a -> Bool) -> [a] -> [a]
breakOn :: Eq a => [a] -> [a] -> ([a], [a])
breakOnEnd :: Eq a => [a] -> [a] -> ([a], [a])
dropEnd :: Int -> [a] -> [a]
groupOn :: Eq b => (a -> b) -> [a] -> [[a]]
groupSort :: Ord k => [(k, v)] -> [(k, [v])]
groupSortBy :: (a -> a -> Ordering) -> [a] -> [[a]]
groupSortOn :: Ord b => (a -> b) -> [a] -> [[a]]
nubOrd :: Ord a => [a] -> [a]
nubOrdBy :: (a -> a -> Ordering) -> [a] -> [a]
nubOrdOn :: Ord b => (a -> b) -> [a] -> [a]
spanEnd :: (a -> Bool) -> [a] -> ([a], [a])
split :: (a -> Bool) -> [a] -> [[a]]
splitOn :: (Partial, Eq a) => [a] -> [a] -> [[a]]
takeEnd :: Int -> [a] -> [a]
takeWhileEnd :: (a -> Bool) -> [a] -> [a]
atMay :: [a] -> Int -> Maybe a
filter :: (a -> Bool) -> [a] -> [a]
group :: Eq a => [a] -> [[a]]
groupBy :: (a -> a -> Bool) -> [a] -> [[a]]
inits :: [a] -> [[a]]
intercalate :: [a] -> [[a]] -> [a]
intersperse :: a -> [a] -> [a]
isPrefixOf :: Eq a => [a] -> [a] -> Bool
isSuffixOf :: Eq a => [a] -> [a] -> Bool
iterate :: (a -> a) -> a -> [a]
iterate' :: (a -> a) -> a -> [a]
lookup :: Eq a => a -> [(a, b)] -> Maybe b
permutations :: [a] -> [[a]]
repeat :: a -> [a]
replicate :: Int -> a -> [a]
reverse :: [a] -> [a]
scanl :: (b -> a -> b) -> b -> [a] -> [b]
scanr :: (a -> b -> b) -> b -> [a] -> [b]
sort :: Ord a => [a] -> [a]
sortBy :: (a -> a -> Ordering) -> [a] -> [a]
sortOn :: Ord b => (a -> b) -> [a] -> [a]
span :: (a -> Bool) -> [a] -> ([a], [a])
splitAt :: Int -> [a] -> ([a], [a])
subsequences :: [a] -> [[a]]
tails :: [a] -> [[a]]
take :: Int -> [a] -> [a]
takeWhile :: (a -> Bool) -> [a] -> [a]
transpose :: [[a]] -> [[a]]
unfoldr :: (b -> Maybe (a, b)) -> b -> [a]
unzip :: [(a, b)] -> ([a], [b])
unzip3 :: [(a, b, c)] -> ([a], [b], [c])
zip :: [a] -> [b] -> [(a, b)]
zip3 :: [a] -> [b] -> [c] -> [(a, b, c)]
zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
zipWith3 :: (a -> b -> c -> d) -> [a] -> [b] -> [c] -> [d]
genericLength :: Num i => [a] -> i
genericTake :: Integral i => i -> [a] -> [a]
genericDrop :: Integral i => i -> [a] -> [a]
genericSplitAt :: Integral i => i -> [a] -> ([a], [a])
genericIndex :: Integral i => [a] -> i -> a
genericReplicate :: Integral i => i -> a -> [a]
cycleDef :: [a] -> [a] -> [a]
cycleMay :: [a] -> Maybe [a]
headDef :: a -> [a] -> a
headMay :: [a] -> Maybe a
initDef :: [a] -> [a] -> [a]
initMay :: [a] -> Maybe [a]
lastDef :: a -> [a] -> a
lastMay :: [a] -> Maybe a
tailDef :: [a] -> [a] -> [a]
tailMay :: [a] -> Maybe [a]
data NonEmpty a = a :| [a]
scanl1 :: (a -> a -> a) -> NonEmpty a -> NonEmpty a
scanr1 :: (a -> a -> a) -> NonEmpty a -> NonEmpty a
head :: NonEmpty a -> a
init :: NonEmpty a -> [a]
last :: NonEmpty a -> a
tail :: NonEmpty a -> [a]
cycle :: NonEmpty a -> NonEmpty a
fst :: (a, b) -> a
snd :: (a, b) -> b
curry :: ((a, b) -> c) -> a -> b -> c
uncurry :: (a -> b -> c) -> (a, b) -> c
swap :: (a, b) -> (b, a)
data Either a b
- = Left a
- | Right b
either :: (a -> c) -> (b -> c) -> Either a b -> c
fromLeft :: a -> Either a b -> a
fromRight :: b -> Either a b -> b
isLeft :: Either a b -> Bool
isRight :: Either a b -> Bool
lefts :: [Either a b] -> [a]
rights :: [Either a b] -> [b]
partitionEithers :: [Either a b] -> ([a], [b])
eitherToMaybe :: Either a b -> Maybe b
maybeToEither :: a -> Maybe b -> Either a b
data Char
class IsString a where
- fromString :: String -> a
data Map k a
data Set a
data Integer
data Natural
data Int
data Int16
data Int32
data Int64
data Int8
data Word
data Word16
data Word32
data Word64
data Word8
data Float
data Double
class Num a where
- (+) :: a -> a -> a
- (-) :: a -> a -> a
- (*) :: a -> a -> a
- negate :: a -> a
- abs :: a -> a
- signum :: a -> a
- fromInteger :: Integer -> a
subtract :: Num a => a -> a -> a
(^) :: (Num a, Integral b) => a -> b -> a
class (Num a, Ord a) => Real a where
- toRational :: a -> Rational
realToFrac :: (Real a, Fractional b) => a -> b
class (Real a, Enum a) => Integral a where
- quot :: a -> a -> a
- rem :: a -> a -> a
- div :: a -> a -> a
- mod :: a -> a -> a
- quotRem :: a -> a -> (a, a)
- divMod :: a -> a -> (a, a)
- toInteger :: a -> Integer
toIntegralSized :: (Integral a, Integral b, Bits a, Bits b) => a -> Maybe b
even :: Integral a => a -> Bool
odd :: Integral a => a -> Bool
class Num a => Fractional a where
- (/) :: a -> a -> a
- recip :: a -> a
- fromRational :: Rational -> a
(^^) :: (Fractional a, Integral b) => a -> b -> a
class Fractional a => Floating a where
- pi :: a
- exp :: a -> a
- log :: a -> a
- sqrt :: a -> a
- (**) :: a -> a -> a
- logBase :: a -> a -> a
- sin :: a -> a
- cos :: a -> a
- tan :: a -> a
- asin :: a -> a
- acos :: a -> a
- atan :: a -> a
- sinh :: a -> a
- cosh :: a -> a
- tanh :: a -> a
- asinh :: a -> a
- acosh :: a -> a
- atanh :: a -> a
class (Real a, Fractional a) => RealFrac a where
- properFraction :: Integral b => a -> (b, a)
- truncate :: Integral b => a -> b
- round :: Integral b => a -> b
- ceiling :: Integral b => a -> b
- floor :: Integral b => a -> b
class (RealFrac a, Floating a) => RealFloat a where
- floatRadix :: a -> Integer
- floatDigits :: a -> Int
- floatRange :: a -> (Int, Int)
- decodeFloat :: a -> (Integer, Int)
- encodeFloat :: Integer -> Int -> a
- exponent :: a -> Int
- significand :: a -> a
- scaleFloat :: Int -> a -> a
- isNaN :: a -> Bool
- isInfinite :: a -> Bool
- isDenormalized :: a -> Bool
- isNegativeZero :: a -> Bool
- isIEEE :: a -> Bool
- atan2 :: a -> a -> a
class Show a
class Show1 (f :: Type -> Type)
class Show2 (f :: Type -> Type -> Type)
show :: (Show a, StringConv String b) => a -> b
class Read a
class Read1 (f :: Type -> Type)
class Read2 (f :: Type -> Type -> Type)
readMaybe :: Read a => String -> Maybe a
class Eq a where
- (==) :: a -> a -> Bool
- (/=) :: a -> a -> Bool
class Eq1 (f :: Type -> Type)
class Eq2 (f :: Type -> Type -> Type)
class Eq a => Ord a where
- compare :: a -> a -> Ordering
- (<) :: a -> a -> Bool
- (<=) :: a -> a -> Bool
- (>) :: a -> a -> Bool
- (>=) :: a -> a -> Bool
- max :: a -> a -> a
- min :: a -> a -> a
class Eq1 f => Ord1 (f :: Type -> Type)
class Eq2 f => Ord2 (f :: Type -> Type -> Type)
data Ordering
- = LT
- | EQ
- | GT
newtype Down a = Down a
comparing :: Ord a => (b -> a) -> b -> b -> Ordering
class Enum a where
- fromEnum :: a -> Int
- enumFrom :: a -> [a]
- enumFromThen :: a -> a -> [a]
- enumFromTo :: a -> a -> [a]
- enumFromThenTo :: a -> a -> a -> [a]
toEnumMay :: (Enum a, Bounded a) => Int -> Maybe a
toEnumDef :: (Enum a, Bounded a) => a -> Int -> a
predMay :: (Enum a, Eq a, Bounded a) => a -> Maybe a
predDef :: (Enum a, Eq a, Bounded a) => a -> a -> a
succMay :: (Enum a, Eq a, Bounded a) => a -> Maybe a
succDef :: (Enum a, Eq a, Bounded a) => a -> a -> a
class Bounded a where
- minBound :: a
- maxBound :: a
class Category (cat :: k -> k -> Type) where
- (.) :: forall (b :: k) (c :: k) (a :: k). cat b c -> cat a b -> cat a c
(<<<) :: forall k cat (b :: k) (c :: k) (a :: k). Category cat => cat b c -> cat a b -> cat a c
(>>>) :: forall k cat (a :: k) (b :: k) (c :: k). Category cat => cat a b -> cat b c -> cat a c
newtype First a = First {
- getFirst :: a
}
newtype Last a = Last {
- getLast :: a
}
newtype Max a = Max {
- getMax :: a
}
newtype Min a = Min {
- getMin :: a
}
class Semigroup a where
- (<>) :: a -> a -> a
- sconcat :: NonEmpty a -> a
- stimes :: Integral b => b -> a -> a
newtype All = All {
- getAll :: Bool
}
newtype Alt (f :: k -> Type) (a :: k) = Alt {
- getAlt :: f a
}
newtype Any = Any {
- getAny :: Bool
}
newtype Dual a = Dual {
- getDual :: a
}
newtype Endo a = Endo {
- appEndo :: a -> a
}
class Semigroup a => Monoid a where
- mempty :: a
- mappend :: a -> a -> a
- mconcat :: [a] -> a
newtype Const a (b :: k) = Const {
- getConst :: a
}
(<&>) :: Functor f => f a -> (a -> b) -> f b
(<$) :: Functor f => a -> f b -> f a
(<$>) :: Functor f => (a -> b) -> f a -> f b
($>) :: Functor f => f a -> b -> f b
fmap :: Functor f => (a -> b) -> f a -> f b
newtype Identity a = Identity {
- runIdentity :: a
}
void :: Functor f => f a -> f ()
class Contravariant (f :: Type -> Type) where
- contramap :: (a -> b) -> f b -> f a
- (>$) :: b -> f b -> f a
($<) :: Contravariant f => f b -> b -> f a
(>$<) :: Contravariant f => (a -> b) -> f b -> f a
(>$$<) :: Contravariant f => f b -> (a -> b) -> f a
class Foldable (t :: Type -> Type) where
- fold :: Monoid m => t m -> m
- foldMap :: Monoid m => (a -> m) -> t a -> m
- foldr :: (a -> b -> b) -> b -> t a -> b
- foldr' :: (a -> b -> b) -> b -> t a -> b
- foldl :: (b -> a -> b) -> b -> t a -> b
- foldl' :: (b -> a -> b) -> b -> t a -> b
- toList :: t a -> [a]
- elem :: Eq a => a -> t a -> Bool
- sum :: Num a => t a -> a
- product :: Num a => t a -> a
all :: Foldable t => (a -> Bool) -> t a -> Bool
and :: Foldable t => t Bool -> Bool
any :: Foldable t => (a -> Bool) -> t a -> Bool
asum :: (Foldable t, Alternative f) => t (f a) -> f a
concat :: Foldable t => t [a] -> [a]
concatMap :: Foldable t => (a -> [b]) -> t a -> [b]
find :: Foldable t => (a -> Bool) -> t a -> Maybe a
foldlM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b
foldrM :: (Foldable t, Monad m) => (a -> b -> m b) -> b -> t a -> m b
for_ :: (Foldable t, Applicative f) => t a -> (a -> f b) -> f ()
length :: Foldable t => t a -> Int
notElem :: (Foldable t, Eq a) => a -> t a -> Bool
null :: Foldable t => t a -> Bool
or :: Foldable t => t Bool -> Bool
sequenceA_ :: (Foldable t, Applicative f) => t (f a) -> f ()
traverse_ :: (Foldable t, Applicative f) => (a -> f b) -> t a -> f ()
foldl1May :: Foldable t => (a -> a -> a) -> t a -> Maybe a
foldr1May :: Foldable t => (a -> a -> a) -> t a -> Maybe a
maximumBound :: (Foldable f, Ord a) => a -> f a -> a
maximumBoundBy :: Foldable f => a -> (a -> a -> Ordering) -> f a -> a
maximumBounded :: (Foldable f, Ord a, Bounded a) => f a -> a
maximumByMay :: Foldable t => (a -> a -> Ordering) -> t a -> Maybe a
maximumMay :: (Foldable t, Ord a) => t a -> Maybe a
minimumBound :: (Foldable f, Ord a) => a -> f a -> a
minimumBoundBy :: Foldable f => a -> (a -> a -> Ordering) -> f a -> a
minimumBounded :: (Foldable f, Ord a, Bounded a) => f a -> a
minimumByMay :: Foldable t => (a -> a -> Ordering) -> t a -> Maybe a
minimumMay :: (Foldable t, Ord a) => t a -> Maybe a
class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where
- traverse :: Applicative f => (a -> f b) -> t a -> f (t b)
- sequenceA :: Applicative f => t (f a) -> f (t a)
for :: (Traversable t, Applicative f) => t a -> (a -> f b) -> f (t b)
mapAccumL :: Traversable t => (a -> b -> (a, c)) -> a -> t b -> (a, t c)
mapAccumR :: Traversable t => (a -> b -> (a, c)) -> a -> t b -> (a, t c)
class Functor f => Applicative (f :: Type -> Type) where
- pure :: a -> f a
- (<*>) :: f (a -> b) -> f a -> f b
- (*>) :: f a -> f b -> f b
- (<*) :: f a -> f b -> f a
newtype ZipList a = ZipList {
- getZipList :: [a]
}
(<**>) :: Applicative f => f a -> f (a -> b) -> f b
liftA2 :: Applicative f => (a -> b -> c) -> f a -> f b -> f c
liftA3 :: Applicative f => (a -> b -> c -> d) -> f a -> f b -> f c -> f d
pass :: Applicative f => f ()
class Applicative f => Alternative (f :: Type -> Type) where
- empty :: f a
- (<|>) :: f a -> f a -> f a
- many :: f a -> f [a]
optional :: Alternative f => f a -> f (Maybe a)
some1 :: Alternative f => f a -> f (NonEmpty a)
(<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c
(=<<) :: Monad m => (a -> m b) -> m a -> m b
(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c
(>>) :: Monad m => m a -> m b -> m b
(<$!>) :: Monad m => (a -> b) -> m a -> m b
ap :: Monad m => m (a -> b) -> m a -> m b
(&&^) :: Monad m => m Bool -> m Bool -> m Bool
(||^) :: Monad m => m Bool -> m Bool -> m Bool
allM :: Monad m => (a -> m Bool) -> [a] -> m Bool
andM :: Monad m => [m Bool] -> m Bool
anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool
concatMapM :: Monad m => (a -> m [b]) -> [a] -> m [b]
ifM :: Monad m => m Bool -> m a -> m a -> m a
orM :: Monad m => [m Bool] -> m Bool
unlessM :: Monad m => m Bool -> m () -> m ()
whenM :: Monad m => m Bool -> m () -> m ()
filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a]
class Monad m => MonadFix (m :: Type -> Type) where
- mfix :: (a -> m a) -> m a
foldM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b
foldM_ :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m ()
forever :: Applicative f => f a -> f b
guard :: Alternative f => Bool -> f ()
join :: Monad m => m (m a) -> m a
liftM :: Monad m => (a1 -> r) -> m a1 -> m r
liftM2 :: Monad m => (a1 -> a2 -> r) -> m a1 -> m a2 -> m r
liftM3 :: Monad m => (a1 -> a2 -> a3 -> r) -> m a1 -> m a2 -> m a3 -> m r
liftM4 :: Monad m => (a1 -> a2 -> a3 -> a4 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m r
liftM5 :: Monad m => (a1 -> a2 -> a3 -> a4 -> a5 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m a5 -> m r
mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c])
mfilter :: MonadPlus m => (a -> Bool) -> m a -> m a
class Applicative m => Monad (m :: Type -> Type) where
- (>>=) :: m a -> (a -> m b) -> m b
replicateM :: Applicative m => Int -> m a -> m [a]
replicateM_ :: Applicative m => Int -> m a -> m ()
unless :: Applicative f => Bool -> f () -> f ()
when :: Applicative f => Bool -> f () -> f ()
zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c]
zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m ()
class (Typeable e, Show e) => Exception e
data SomeException
class Bifunctor (p :: Type -> Type -> Type) where
- bimap :: (a -> b) -> (c -> d) -> p a c -> p b d
- first :: (a -> b) -> p a c -> p b c
- second :: (b -> c) -> p a b -> p a c
class Bifoldable (p :: Type -> Type -> Type) where
- bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> p a b -> m
- bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> p a b -> c
bifoldl' :: Bifoldable t => (a -> b -> a) -> (a -> c -> a) -> a -> t b c -> a
bifoldr' :: Bifoldable t => (a -> c -> c) -> (b -> c -> c) -> c -> t a b -> c
bitraverse_ :: (Bifoldable t, Applicative f) => (a -> f c) -> (b -> f d) -> t a b -> f ()
bisequenceA_ :: (Bifoldable t, Applicative f) => t (f a) (f b) -> f ()
bifor_ :: (Bifoldable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f ()
class (Bifunctor t, Bifoldable t) => Bitraversable (t :: Type -> Type -> Type) where
- bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> t a b -> f (t c d)
bifor :: (Bitraversable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f (t c d)
bisequenceA :: (Bitraversable t, Applicative f) => t (f a) (f b) -> f (t a b)
class MonadTrans (t :: (Type -> Type) -> Type -> Type) where
- lift :: Monad m => m a -> t m a
data ThreadId
forkIO :: IO () -> IO ThreadId
forkFinally :: IO a -> (Either SomeException a -> IO ()) -> IO ThreadId
threadDelay :: Int -> IO ()
myThreadId :: IO ThreadId
class Generic a
class Generic1 (f :: k -> Type)
class Typeable (a :: k)
fromIntegral :: (Integral a, Num b) => a -> b
type Type = Type
data Proxy (t :: k) = Proxy
data IO a
class Monad m => MonadIO (m :: Type -> Type) where
- liftIO :: IO a -> m a
print :: (MonadIO m, Show a) => a -> m ()
class Print a
hPutStr :: (Print a, MonadIO m) => Handle -> a -> m ()
putStr :: (Print a, MonadIO m) => a -> m ()
hPutStrLn :: (Print a, MonadIO m) => Handle -> a -> m ()
putStrLn :: (Print a, MonadIO m) => a -> m ()
putErrLn :: (Print a, MonadIO m) => a -> m ()
putText :: MonadIO m => Text -> m ()
putErrText :: MonadIO m => Text -> m ()
putLText :: MonadIO m => Text -> m ()
putByteString :: MonadIO m => ByteString -> m ()
putLByteString :: MonadIO m => ByteString -> m ()
type HasCallStack = ?callStack :: CallStack
class Monad m => MonadFail (m :: Type -> Type)
undefined :: HasCallStack => a
trace :: Text -> a -> a
traceIO :: MonadIO m => Text -> m ()
traceId :: Text -> Text
traceM :: Applicative m => Text -> m ()
traceShow :: Show a => a -> b -> b
traceShowId :: Show a => a -> a
traceShowM :: (Show a, Applicative m) => a -> m ()
data UTCTime
data LocalTime
data NominalDiffTime
data UUID
data ByteString
data Text
type FilePath = String
(<<$>>) :: (Functor f, Functor g) => (a -> b) -> f (g a) -> f (g b)
ordNub :: Ord a => [a] -> [a]
identity :: a -> a

Basic functions

(&) :: a -> (a -> b) -> b infixl 1 #

& is a reverse application operator. This provides notational convenience. Its precedence is one higher than that of the forward application operator $, which allows & to be nested in $.

>>> 5 & (+1) & show
"6"

Since: base-4.8.0.0

($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b infixr 0 #

Application operator. This operator is redundant, since ordinary application (f x) means the same as (f $ x). However, $ has low, right-associative binding precedence, so it sometimes allows parentheses to be omitted; for example:

f $ g $ h x  =  f (g (h x))

It is also useful in higher-order situations, such as map ($ 0) xs, or zipWith ($) fs xs.

Note that ($) is levity-polymorphic in its result type, so that foo $ True where foo :: Bool -> Int# is well-typed.

const :: a -> b -> a #

const x is a unary function which evaluates to x for all inputs.

>>> const 42 "hello"
42

>>> map (const 42) [0..3]
[42,42,42,42]

fix :: (a -> a) -> a #

fix f is the least fixed point of the function f, i.e. the least defined x such that f x = x.

For example, we can write the factorial function using direct recursion as

>>> let fac n = if n <= 1 then 1 else n * fac (n-1) in fac 5
120

This uses the fact that Haskell’s let introduces recursive bindings. We can rewrite this definition using fix,

>>> fix (\rec n -> if n <= 1 then 1 else n * rec (n-1)) 5
120

Instead of making a recursive call, we introduce a dummy parameter rec; when used within fix, this parameter then refers to fix’s argument, hence the recursion is reintroduced.

flip :: (a -> b -> c) -> b -> a -> c #

flip f takes its (first) two arguments in the reverse order of f.

>>> flip (++) "hello" "world"
"worldhello"

on :: (b -> b -> c) -> (a -> b) -> a -> a -> c infixl 0 #

on b u x y runs the binary function b on the results of applying unary function u to two arguments x and y. From the opposite perspective, it transforms two inputs and combines the outputs.

((+) `on` f) x y = f x + f y

Typical usage: sortBy (compare `on` fst).

Algebraic properties:

(*) `on` id = (*) -- (if (*) ∉ {⊥, const ⊥})

```
((*) `on` f) `on` g = (*) `on` (f . g)
```
```
flip on f . flip on g = flip on (g . f)
```

($!) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b infixr 0 #

Strict (call-by-value) application operator. It takes a function and an argument, evaluates the argument to weak head normal form (WHNF), then calls the function with that value.

seq :: forall (r :: RuntimeRep) a (b :: TYPE r). a -> b -> b infixr 0 #

The value of seq a b is bottom if a is bottom, and otherwise equal to b. In other words, it evaluates the first argument a to weak head normal form (WHNF). seq is usually introduced to improve performance by avoiding unneeded laziness.

A note on evaluation order: the expression seq a b does not guarantee that a will be evaluated before b. The only guarantee given by seq is that the both a and b will be evaluated before seq returns a value. In particular, this means that b may be evaluated before a. If you need to guarantee a specific order of evaluation, you must use the function pseq from the "parallel" package.

Basic algebraic types

Void

data Void #

Uninhabited data type

Since: base-4.8.0.0

Instances

Instances details

Eq Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods (==) :: Void -> Void -> Bool # (/=) :: Void -> Void -> Bool #
Data Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Void -> c Void # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Void # toConstr :: Void -> Constr # dataTypeOf :: Void -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Void) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Void) # gmapT :: (forall b. Data b => b -> b) -> Void -> Void # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r # gmapQ :: (forall d. Data d => d -> u) -> Void -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Void -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Void -> m Void # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void #
Ord Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods compare :: Void -> Void -> Ordering # (<) :: Void -> Void -> Bool # (<=) :: Void -> Void -> Bool # (>) :: Void -> Void -> Bool # (>=) :: Void -> Void -> Bool # max :: Void -> Void -> Void # min :: Void -> Void -> Void #
Read Void	Reading a `Void` value is always a parse error, considering `Void` as a data type with no constructors. Since: base-4.8.0.0
Instance details Defined in Data.Void Methods readsPrec :: Int -> ReadS Void # readList :: ReadS [Void] # readPrec :: ReadPrec Void # readListPrec :: ReadPrec [Void] #
Show Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods showsPrec :: Int -> Void -> ShowS # show :: Void -> String # showList :: [Void] -> ShowS #
Ix Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods range :: (Void, Void) -> [Void] # index :: (Void, Void) -> Void -> Int # unsafeIndex :: (Void, Void) -> Void -> Int # inRange :: (Void, Void) -> Void -> Bool # rangeSize :: (Void, Void) -> Int # unsafeRangeSize :: (Void, Void) -> Int #
Generic Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Associated Types type Rep Void :: Type -> Type # Methods from :: Void -> Rep Void x # to :: Rep Void x -> Void #
Semigroup Void	Since: base-4.9.0.0
Instance details Defined in Data.Void Methods (<>) :: Void -> Void -> Void # sconcat :: NonEmpty Void -> Void # stimes :: Integral b => b -> Void -> Void #
Exception Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods toException :: Void -> SomeException # fromException :: SomeException -> Maybe Void # displayException :: Void -> String #
type Rep Void
Instance details Defined in Data.Void type Rep Void = D1 ('MetaData "Void" "Data.Void" "base" 'False) (V1 :: Type -> Type)

Bool

(&&) :: Bool -> Bool -> Bool infixr 3 #

Boolean "and", lazy in the second argument

(||) :: Bool -> Bool -> Bool infixr 2 #

Boolean "or", lazy in the second argument

bool :: a -> a -> Bool -> a #

Case analysis for the Bool type. bool x y p evaluates to x when p is False, and evaluates to y when p is True.

This is equivalent to if p then y else x; that is, one can think of it as an if-then-else construct with its arguments reordered.

Examples

Expand

Basic usage:

>>> bool "foo" "bar" True
"bar"
>>> bool "foo" "bar" False
"foo"

Confirm that bool x y p and if p then y else x are equivalent:

>>> let p = True; x = "bar"; y = "foo"
>>> bool x y p == if p then y else x
True
>>> let p = False
>>> bool x y p == if p then y else x
True

Since: base-4.7.0.0

data Bool #

Constructors

False
True

Instances

Instances details

Bounded Bool	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Bool # maxBound :: Bool #
Enum Bool	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Bool -> Bool # pred :: Bool -> Bool # toEnum :: Int -> Bool # fromEnum :: Bool -> Int # enumFrom :: Bool -> [Bool] # enumFromThen :: Bool -> Bool -> [Bool] # enumFromTo :: Bool -> Bool -> [Bool] # enumFromThenTo :: Bool -> Bool -> Bool -> [Bool] #
Eq Bool
Instance details Defined in GHC.Classes Methods (==) :: Bool -> Bool -> Bool # (/=) :: Bool -> Bool -> Bool #
Ord Bool
Instance details Defined in GHC.Classes Methods compare :: Bool -> Bool -> Ordering # (<) :: Bool -> Bool -> Bool # (<=) :: Bool -> Bool -> Bool # (>) :: Bool -> Bool -> Bool # (>=) :: Bool -> Bool -> Bool # max :: Bool -> Bool -> Bool # min :: Bool -> Bool -> Bool #
Read Bool	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Bool # readList :: ReadS [Bool] # readPrec :: ReadPrec Bool # readListPrec :: ReadPrec [Bool] #
Show Bool	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Bool -> ShowS # show :: Bool -> String # showList :: [Bool] -> ShowS #
Generic Bool	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep Bool :: Type -> Type # Methods from :: Bool -> Rep Bool x # to :: Rep Bool x -> Bool #
Bits Bool	Interpret `Bool` as 1-bit bit-field Since: base-4.7.0.0
Instance details Defined in Data.Bits Methods (.&.) :: Bool -> Bool -> Bool # (.\|.) :: Bool -> Bool -> Bool # xor :: Bool -> Bool -> Bool # complement :: Bool -> Bool # shift :: Bool -> Int -> Bool # rotate :: Bool -> Int -> Bool # zeroBits :: Bool # bit :: Int -> Bool # setBit :: Bool -> Int -> Bool # clearBit :: Bool -> Int -> Bool # complementBit :: Bool -> Int -> Bool # testBit :: Bool -> Int -> Bool # bitSizeMaybe :: Bool -> Maybe Int # bitSize :: Bool -> Int # isSigned :: Bool -> Bool # shiftL :: Bool -> Int -> Bool # unsafeShiftL :: Bool -> Int -> Bool # shiftR :: Bool -> Int -> Bool # unsafeShiftR :: Bool -> Int -> Bool # rotateL :: Bool -> Int -> Bool # rotateR :: Bool -> Int -> Bool # popCount :: Bool -> Int #
FiniteBits Bool	Since: base-4.7.0.0
Instance details Defined in Data.Bits Methods finiteBitSize :: Bool -> Int # countLeadingZeros :: Bool -> Int # countTrailingZeros :: Bool -> Int #
SingKind Bool	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type DemoteRep Bool Methods fromSing :: forall (a :: Bool). Sing a -> DemoteRep Bool
SingI 'False	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods sing :: Sing 'False
SingI 'True	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods sing :: Sing 'True
type Rep Bool
Instance details Defined in GHC.Generics type Rep Bool = D1 ('MetaData "Bool" "GHC.Types" "ghc-prim" 'False) (C1 ('MetaCons "False" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "True" 'PrefixI 'False) (U1 :: Type -> Type))
type DemoteRep Bool
Instance details Defined in GHC.Generics type DemoteRep Bool = Bool
data Sing (a :: Bool)
Instance details Defined in GHC.Generics data Sing (a :: Bool) where STrue :: Sing 'True SFalse :: Sing 'False

not :: Bool -> Bool #

Boolean "not"

otherwise :: Bool #

otherwise is defined as the value True. It helps to make guards more readable. eg.

 f x | x < 0     = ...
     | otherwise = ...

Maybe

(?:) :: Maybe a -> a -> a infix 1 Source #

An infix form of fromMaybe with arguments flipped.

catMaybes :: [Maybe a] -> [a] #

The catMaybes function takes a list of Maybes and returns a list of all the Just values.

Examples

Expand

Basic usage:

>>> catMaybes [Just 1, Nothing, Just 3]
[1,3]

When constructing a list of Maybe values, catMaybes can be used to return all of the "success" results (if the list is the result of a map, then mapMaybe would be more appropriate):

>>> import Text.Read ( readMaybe )
>>> [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
[Just 1,Nothing,Just 3]
>>> catMaybes $ [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ]
[1,3]

fromMaybe :: a -> Maybe a -> a #

The fromMaybe function takes a default value and and Maybe value. If the Maybe is Nothing, it returns the default values; otherwise, it returns the value contained in the Maybe.

Examples

Expand

Basic usage:

>>> fromMaybe "" (Just "Hello, World!")
"Hello, World!"

>>> fromMaybe "" Nothing
""

Read an integer from a string using readMaybe. If we fail to parse an integer, we want to return 0 by default:

>>> import Text.Read ( readMaybe )
>>> fromMaybe 0 (readMaybe "5")
5
>>> fromMaybe 0 (readMaybe "")
0

isJust :: Maybe a -> Bool #

The isJust function returns True iff its argument is of the form Just _.

Examples

Expand

Basic usage:

>>> isJust (Just 3)
True

>>> isJust (Just ())
True

>>> isJust Nothing
False

Only the outer constructor is taken into consideration:

>>> isJust (Just Nothing)
True

isNothing :: Maybe a -> Bool #

The isNothing function returns True iff its argument is Nothing.

Examples

Expand

Basic usage:

>>> isNothing (Just 3)
False

>>> isNothing (Just ())
False

>>> isNothing Nothing
True

Only the outer constructor is taken into consideration:

>>> isNothing (Just Nothing)
False

mapMaybe :: (a -> Maybe b) -> [a] -> [b] #

The mapMaybe function is a version of map which can throw out elements. In particular, the functional argument returns something of type Maybe b. If this is Nothing, no element is added on to the result list. If it is Just b, then b is included in the result list.

Examples

Expand

Using mapMaybe f x is a shortcut for catMaybes $ map f x in most cases:

>>> import Text.Read ( readMaybe )
>>> let readMaybeInt = readMaybe :: String -> Maybe Int
>>> mapMaybe readMaybeInt ["1", "Foo", "3"]
[1,3]
>>> catMaybes $ map readMaybeInt ["1", "Foo", "3"]
[1,3]

If we map the Just constructor, the entire list should be returned:

>>> mapMaybe Just [1,2,3]
[1,2,3]

maybe :: b -> (a -> b) -> Maybe a -> b #

The maybe function takes a default value, a function, and a Maybe value. If the Maybe value is Nothing, the function returns the default value. Otherwise, it applies the function to the value inside the Just and returns the result.

Examples

Expand

Basic usage:

>>> maybe False odd (Just 3)
True

>>> maybe False odd Nothing
False

Read an integer from a string using readMaybe. If we succeed, return twice the integer; that is, apply (*2) to it. If instead we fail to parse an integer, return 0 by default:

>>> import Text.Read ( readMaybe )
>>> maybe 0 (*2) (readMaybe "5")
10
>>> maybe 0 (*2) (readMaybe "")
0

Apply show to a Maybe Int. If we have Just n, we want to show the underlying Int n. But if we have Nothing, we return the empty string instead of (for example) "Nothing":

>>> maybe "" show (Just 5)
"5"
>>> maybe "" show Nothing
""

data Maybe a #

The Maybe type encapsulates an optional value. A value of type Maybe a either contains a value of type a (represented as Just a), or it is empty (represented as Nothing). Using Maybe is a good way to deal with errors or exceptional cases without resorting to drastic measures such as error.

The Maybe type is also a monad. It is a simple kind of error monad, where all errors are represented by Nothing. A richer error monad can be built using the Either type.

Constructors

Nothing
Just a

Instances

Instances details

Monad Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b # (>>) :: Maybe a -> Maybe b -> Maybe b # return :: a -> Maybe a #
Functor Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> Maybe a -> Maybe b # (<$) :: a -> Maybe b -> Maybe a #
MonadFix Maybe	Since: base-2.1
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Maybe a) -> Maybe a #
MonadFail Maybe	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fail Methods fail :: String -> Maybe a #
Applicative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> Maybe a # (<>) :: Maybe (a -> b) -> Maybe a -> Maybe b # liftA2 :: (a -> b -> c) -> Maybe a -> Maybe b -> Maybe c # (>) :: Maybe a -> Maybe b -> Maybe b # (<*) :: Maybe a -> Maybe b -> Maybe a #
Foldable Maybe	Since: base-2.1
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # toList :: Maybe a -> [a] # null :: Maybe a -> Bool # length :: Maybe a -> Int # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # sum :: Num a => Maybe a -> a # product :: Num a => Maybe a -> a #
Traversable Maybe	Since: base-2.1
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Maybe a -> f (Maybe b) # sequenceA :: Applicative f => Maybe (f a) -> f (Maybe a) # mapM :: Monad m => (a -> m b) -> Maybe a -> m (Maybe b) # sequence :: Monad m => Maybe (m a) -> m (Maybe a) #
Eq1 Maybe	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> Maybe a -> Maybe b -> Bool #
Ord1 Maybe	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> Maybe a -> Maybe b -> Ordering #
Read1 Maybe	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Maybe a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Maybe a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Maybe a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Maybe a] #
Show1 Maybe	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Maybe a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Maybe a] -> ShowS #
Alternative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods empty :: Maybe a # (<\|>) :: Maybe a -> Maybe a -> Maybe a # some :: Maybe a -> Maybe [a] # many :: Maybe a -> Maybe [a] #
MonadPlus Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods mzero :: Maybe a # mplus :: Maybe a -> Maybe a -> Maybe a #
Eq a => Eq (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods (==) :: Maybe a -> Maybe a -> Bool # (/=) :: Maybe a -> Maybe a -> Bool #
Ord a => Ord (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods compare :: Maybe a -> Maybe a -> Ordering # (<) :: Maybe a -> Maybe a -> Bool # (<=) :: Maybe a -> Maybe a -> Bool # (>) :: Maybe a -> Maybe a -> Bool # (>=) :: Maybe a -> Maybe a -> Bool # max :: Maybe a -> Maybe a -> Maybe a # min :: Maybe a -> Maybe a -> Maybe a #
Read a => Read (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (Maybe a) # readList :: ReadS [Maybe a] # readPrec :: ReadPrec (Maybe a) # readListPrec :: ReadPrec [Maybe a] #
Show a => Show (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Maybe a -> ShowS # show :: Maybe a -> String # showList :: [Maybe a] -> ShowS #
Generic (Maybe a)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Maybe a) :: Type -> Type # Methods from :: Maybe a -> Rep (Maybe a) x # to :: Rep (Maybe a) x -> Maybe a #
Semigroup a => Semigroup (Maybe a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: Maybe a -> Maybe a -> Maybe a # sconcat :: NonEmpty (Maybe a) -> Maybe a # stimes :: Integral b => b -> Maybe a -> Maybe a #
Semigroup a => Monoid (Maybe a)	Lift a semigroup into `Maybe` forming a `Monoid` according to http://en.wikipedia.org/wiki/Monoid: "Any semigroup `S` may be turned into a monoid simply by adjoining an element `e` not in `S` and defining `ee = e` and `es = s = se` for all `s ∈ S`." Since 4.11.0: constraint on inner `a` value generalised from `Monoid` to `Semigroup`. Since: base-2.1*
Instance details Defined in GHC.Base Methods mempty :: Maybe a # mappend :: Maybe a -> Maybe a -> Maybe a # mconcat :: [Maybe a] -> Maybe a #
SingKind a => SingKind (Maybe a)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type DemoteRep (Maybe a) Methods fromSing :: forall (a0 :: Maybe a). Sing a0 -> DemoteRep (Maybe a)
Generic1 Maybe	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 Maybe :: k -> Type # Methods from1 :: forall (a :: k). Maybe a -> Rep1 Maybe a # to1 :: forall (a :: k). Rep1 Maybe a -> Maybe a #
SingI ('Nothing :: Maybe a)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods sing :: Sing 'Nothing
SingI a2 => SingI ('Just a2 :: Maybe a1)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods sing :: Sing ('Just a2)
type Rep (Maybe a)
Instance details Defined in GHC.Generics type Rep (Maybe a) = D1 ('MetaData "Maybe" "GHC.Maybe" "base" 'False) (C1 ('MetaCons "Nothing" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Just" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
type DemoteRep (Maybe a)
Instance details Defined in GHC.Generics type DemoteRep (Maybe a) = Maybe (DemoteRep a)
data Sing (b :: Maybe a)
Instance details Defined in GHC.Generics data Sing (b :: Maybe a) where SNothing :: forall a. Sing ('Nothing :: Maybe a) SJust :: forall a (a1 :: a). Sing a1 -> Sing ('Just a1)
type Rep1 Maybe
Instance details Defined in GHC.Generics type Rep1 Maybe = D1 ('MetaData "Maybe" "GHC.Maybe" "base" 'False) (C1 ('MetaCons "Nothing" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Just" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

List

break :: (a -> Bool) -> [a] -> ([a], [a]) #

break, applied to a predicate p and a list xs, returns a tuple where first element is longest prefix (possibly empty) of xs of elements that do not satisfy p and second element is the remainder of the list:

break (> 3) [1,2,3,4,1,2,3,4] == ([1,2,3],[4,1,2,3,4])
break (< 9) [1,2,3] == ([],[1,2,3])
break (> 9) [1,2,3] == ([1,2,3],[])

break p is equivalent to span (not . p).

drop :: Int -> [a] -> [a] #

drop n xs returns the suffix of xs after the first n elements, or [] if n > length xs:

drop 6 "Hello World!" == "World!"
drop 3 [1,2,3,4,5] == [4,5]
drop 3 [1,2] == []
drop 3 [] == []
drop (-1) [1,2] == [1,2]
drop 0 [1,2] == [1,2]

It is an instance of the more general genericDrop, in which n may be of any integral type.

dropWhile :: (a -> Bool) -> [a] -> [a] #

dropWhile p xs returns the suffix remaining after takeWhile p xs:

dropWhile (< 3) [1,2,3,4,5,1,2,3] == [3,4,5,1,2,3]
dropWhile (< 9) [1,2,3] == []
dropWhile (< 0) [1,2,3] == [1,2,3]

dropWhileEnd :: (a -> Bool) -> [a] -> [a] #

The dropWhileEnd function drops the largest suffix of a list in which the given predicate holds for all elements. For example:

>>> dropWhileEnd isSpace "foo\n"
"foo"

>>> dropWhileEnd isSpace "foo bar"
"foo bar"

dropWhileEnd isSpace ("foo\n" ++ undefined) == "foo" ++ undefined

Since: base-4.5.0.0

breakOn :: Eq a => [a] -> [a] -> ([a], [a]) #

breakOnEnd :: Eq a => [a] -> [a] -> ([a], [a]) #

dropEnd :: Int -> [a] -> [a] #

groupOn :: Eq b => (a -> b) -> [a] -> [[a]] #

groupSort :: Ord k => [(k, v)] -> [(k, [v])] #

groupSortBy :: (a -> a -> Ordering) -> [a] -> [[a]] #

groupSortOn :: Ord b => (a -> b) -> [a] -> [[a]] #

nubOrd :: Ord a => [a] -> [a] #

nubOrdBy :: (a -> a -> Ordering) -> [a] -> [a] #

nubOrdOn :: Ord b => (a -> b) -> [a] -> [a] #

spanEnd :: (a -> Bool) -> [a] -> ([a], [a]) #

split :: (a -> Bool) -> [a] -> [[a]] #

splitOn :: (Partial, Eq a) => [a] -> [a] -> [[a]] #

takeEnd :: Int -> [a] -> [a] #

takeWhileEnd :: (a -> Bool) -> [a] -> [a] #

atMay :: [a] -> Int -> Maybe a Source #

filter :: (a -> Bool) -> [a] -> [a] #

$\mathcal{O}(n)$. filter, applied to a predicate and a list, returns the list of those elements that satisfy the predicate; i.e.,

filter p xs = [ x | x <- xs, p x]

>>> filter odd [1, 2, 3]
[1,3]

group :: Eq a => [a] -> [[a]] #

The group function takes a list and returns a list of lists such that the concatenation of the result is equal to the argument. Moreover, each sublist in the result contains only equal elements. For example,

>>> group "Mississippi"
["M","i","ss","i","ss","i","pp","i"]

It is a special case of groupBy, which allows the programmer to supply their own equality test.

groupBy :: (a -> a -> Bool) -> [a] -> [[a]] #

The groupBy function is the non-overloaded version of group.

inits :: [a] -> [[a]] #

The inits function returns all initial segments of the argument, shortest first. For example,

>>> inits "abc"
["","a","ab","abc"]

Note that inits has the following strictness property: inits (xs ++ _|_) = inits xs ++ _|_

In particular, inits _|_ = [] : _|_

intercalate :: [a] -> [[a]] -> [a] #

intercalate xs xss is equivalent to (concat (intersperse xs xss)). It inserts the list xs in between the lists in xss and concatenates the result.

>>> intercalate ", " ["Lorem", "ipsum", "dolor"]
"Lorem, ipsum, dolor"

intersperse :: a -> [a] -> [a] #

$\mathcal{O}(n)$. The intersperse function takes an element and a list and `intersperses' that element between the elements of the list. For example,

>>> intersperse ',' "abcde"
"a,b,c,d,e"

isPrefixOf :: Eq a => [a] -> [a] -> Bool #

$\mathcal{O}(\min(m,n))$. The isPrefixOf function takes two lists and returns True iff the first list is a prefix of the second.

>>> "Hello" `isPrefixOf` "Hello World!"
True

>>> "Hello" `isPrefixOf` "Wello Horld!"
False

isSuffixOf :: Eq a => [a] -> [a] -> Bool #

The isSuffixOf function takes two lists and returns True iff the first list is a suffix of the second. The second list must be finite.

>>> "ld!" `isSuffixOf` "Hello World!"
True

>>> "World" `isSuffixOf` "Hello World!"
False

iterate :: (a -> a) -> a -> [a] #

iterate f x returns an infinite list of repeated applications of f to x:

iterate f x == [x, f x, f (f x), ...]

Note that iterate is lazy, potentially leading to thunk build-up if the consumer doesn't force each iterate. See iterate' for a strict variant of this function.

iterate' :: (a -> a) -> a -> [a] #

iterate' is the strict version of iterate.

It ensures that the result of each application of force to weak head normal form before proceeding.

lookup :: Eq a => a -> [(a, b)] -> Maybe b #

$\mathcal{O}(n)$. lookup key assocs looks up a key in an association list.

>>> lookup 2 [(1, "first"), (2, "second"), (3, "third")]
Just "second"

permutations :: [a] -> [[a]] #

The permutations function returns the list of all permutations of the argument.

>>> permutations "abc"
["abc","bac","cba","bca","cab","acb"]

repeat :: a -> [a] #

repeat x is an infinite list, with x the value of every element.

replicate :: Int -> a -> [a] #

replicate n x is a list of length n with x the value of every element. It is an instance of the more general genericReplicate, in which n may be of any integral type.

reverse :: [a] -> [a] #

reverse xs returns the elements of xs in reverse order. xs must be finite.

scanl :: (b -> a -> b) -> b -> [a] -> [b] #

$\mathcal{O}(n)$. scanl is similar to foldl, but returns a list of successive reduced values from the left:

scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]

Note that

last (scanl f z xs) == foldl f z xs.

scanr :: (a -> b -> b) -> b -> [a] -> [b] #

$\mathcal{O}(n)$. scanr is the right-to-left dual of scanl. Note that

head (scanr f z xs) == foldr f z xs.

sort :: Ord a => [a] -> [a] #

The sort function implements a stable sorting algorithm. It is a special case of sortBy, which allows the programmer to supply their own comparison function.

Elements are arranged from lowest to highest, keeping duplicates in the order they appeared in the input.

>>> sort [1,6,4,3,2,5]
[1,2,3,4,5,6]

sortBy :: (a -> a -> Ordering) -> [a] -> [a] #

The sortBy function is the non-overloaded version of sort.

>>> sortBy (\(a,_) (b,_) -> compare a b) [(2, "world"), (4, "!"), (1, "Hello")]
[(1,"Hello"),(2,"world"),(4,"!")]

sortOn :: Ord b => (a -> b) -> [a] -> [a] #

Sort a list by comparing the results of a key function applied to each element. sortOn f is equivalent to sortBy (comparing f), but has the performance advantage of only evaluating f once for each element in the input list. This is called the decorate-sort-undecorate paradigm, or Schwartzian transform.

Elements are arranged from from lowest to highest, keeping duplicates in the order they appeared in the input.

>>> sortOn fst [(2, "world"), (4, "!"), (1, "Hello")]
[(1,"Hello"),(2,"world"),(4,"!")]

Since: base-4.8.0.0

span :: (a -> Bool) -> [a] -> ([a], [a]) #

span, applied to a predicate p and a list xs, returns a tuple where first element is longest prefix (possibly empty) of xs of elements that satisfy p and second element is the remainder of the list:

span (< 3) [1,2,3,4,1,2,3,4] == ([1,2],[3,4,1,2,3,4])
span (< 9) [1,2,3] == ([1,2,3],[])
span (< 0) [1,2,3] == ([],[1,2,3])

span p xs is equivalent to (takeWhile p xs, dropWhile p xs)

splitAt :: Int -> [a] -> ([a], [a]) #

splitAt n xs returns a tuple where first element is xs prefix of length n and second element is the remainder of the list:

splitAt 6 "Hello World!" == ("Hello ","World!")
splitAt 3 [1,2,3,4,5] == ([1,2,3],[4,5])
splitAt 1 [1,2,3] == ([1],[2,3])
splitAt 3 [1,2,3] == ([1,2,3],[])
splitAt 4 [1,2,3] == ([1,2,3],[])
splitAt 0 [1,2,3] == ([],[1,2,3])
splitAt (-1) [1,2,3] == ([],[1,2,3])

It is equivalent to (take n xs, drop n xs) when n is not _|_ (splitAt _|_ xs = _|_). splitAt is an instance of the more general genericSplitAt, in which n may be of any integral type.

subsequences :: [a] -> [[a]] #

The subsequences function returns the list of all subsequences of the argument.

>>> subsequences "abc"
["","a","b","ab","c","ac","bc","abc"]

tails :: [a] -> [[a]] #

$\mathcal{O}(n)$. The tails function returns all final segments of the argument, longest first. For example,

>>> tails "abc"
["abc","bc","c",""]

Note that tails has the following strictness property: tails _|_ = _|_ : _|_

take :: Int -> [a] -> [a] #

take n, applied to a list xs, returns the prefix of xs of length n, or xs itself if n > length xs:

take 5 "Hello World!" == "Hello"
take 3 [1,2,3,4,5] == [1,2,3]
take 3 [1,2] == [1,2]
take 3 [] == []
take (-1) [1,2] == []
take 0 [1,2] == []

It is an instance of the more general genericTake, in which n may be of any integral type.

takeWhile :: (a -> Bool) -> [a] -> [a] #

takeWhile, applied to a predicate p and a list xs, returns the longest prefix (possibly empty) of xs of elements that satisfy p:

takeWhile (< 3) [1,2,3,4,1,2,3,4] == [1,2]
takeWhile (< 9) [1,2,3] == [1,2,3]
takeWhile (< 0) [1,2,3] == []

transpose :: [[a]] -> [[a]] #

The transpose function transposes the rows and columns of its argument. For example,

>>> transpose [[1,2,3],[4,5,6]]
[[1,4],[2,5],[3,6]]

If some of the rows are shorter than the following rows, their elements are skipped:

>>> transpose [[10,11],[20],[],[30,31,32]]
[[10,20,30],[11,31],[32]]

unfoldr :: (b -> Maybe (a, b)) -> b -> [a] #

The unfoldr function is a `dual' to foldr: while foldr reduces a list to a summary value, unfoldr builds a list from a seed value. The function takes the element and returns Nothing if it is done producing the list or returns Just (a,b), in which case, a is a prepended to the list and b is used as the next element in a recursive call. For example,

iterate f == unfoldr (\x -> Just (x, f x))

In some cases, unfoldr can undo a foldr operation:

unfoldr f' (foldr f z xs) == xs

if the following holds:

f' (f x y) = Just (x,y)
f' z       = Nothing

A simple use of unfoldr:

>>> unfoldr (\b -> if b == 0 then Nothing else Just (b, b-1)) 10
[10,9,8,7,6,5,4,3,2,1]

unzip :: [(a, b)] -> ([a], [b]) #

unzip transforms a list of pairs into a list of first components and a list of second components.

unzip3 :: [(a, b, c)] -> ([a], [b], [c]) #

The unzip3 function takes a list of triples and returns three lists, analogous to unzip.

zip :: [a] -> [b] -> [(a, b)] #

$\mathcal{O}(\min(m,n))$. zip takes two lists and returns a list of corresponding pairs.

zip [1, 2] ['a', 'b'] = [(1, 'a'), (2, 'b')]

If one input list is short, excess elements of the longer list are discarded:

zip [1] ['a', 'b'] = [(1, 'a')]
zip [1, 2] ['a'] = [(1, 'a')]

zip is right-lazy:

zip [] _|_ = []
zip _|_ [] = _|_

zip is capable of list fusion, but it is restricted to its first list argument and its resulting list.

zip3 :: [a] -> [b] -> [c] -> [(a, b, c)] #

zip3 takes three lists and returns a list of triples, analogous to zip. It is capable of list fusion, but it is restricted to its first list argument and its resulting list.

zipWith :: (a -> b -> c) -> [a] -> [b] -> [c] #

$\mathcal{O}(\min(m,n))$. zipWith generalises zip by zipping with the function given as the first argument, instead of a tupling function. For example, zipWith (+) is applied to two lists to produce the list of corresponding sums:

>>> zipWith (+) [1, 2, 3] [4, 5, 6]
[5,7,9]

zipWith is right-lazy:

zipWith f [] _|_ = []

zipWith is capable of list fusion, but it is restricted to its first list argument and its resulting list.

zipWith3 :: (a -> b -> c -> d) -> [a] -> [b] -> [c] -> [d] #

The zipWith3 function takes a function which combines three elements, as well as three lists and returns a list of their point-wise combination, analogous to zipWith. It is capable of list fusion, but it is restricted to its first list argument and its resulting list.

genericLength :: Num i => [a] -> i #

$\mathcal{O}(n)$. The genericLength function is an overloaded version of length. In particular, instead of returning an Int, it returns any type which is an instance of Num. It is, however, less efficient than length.

>>> genericLength [1, 2, 3] :: Int
3
>>> genericLength [1, 2, 3] :: Float
3.0

genericTake :: Integral i => i -> [a] -> [a] #

The genericTake function is an overloaded version of take, which accepts any Integral value as the number of elements to take.

genericDrop :: Integral i => i -> [a] -> [a] #

The genericDrop function is an overloaded version of drop, which accepts any Integral value as the number of elements to drop.

genericSplitAt :: Integral i => i -> [a] -> ([a], [a]) #

The genericSplitAt function is an overloaded version of splitAt, which accepts any Integral value as the position at which to split.

genericIndex :: Integral i => [a] -> i -> a #

The genericIndex function is an overloaded version of !!, which accepts any Integral value as the index.

genericReplicate :: Integral i => i -> a -> [a] #

The genericReplicate function is an overloaded version of replicate, which accepts any Integral value as the number of repetitions to make.

cycleDef :: [a] -> [a] -> [a] #

cycleMay :: [a] -> Maybe [a] #

headDef :: a -> [a] -> a #

headMay :: [a] -> Maybe a #

initDef :: [a] -> [a] -> [a] #

initMay :: [a] -> Maybe [a] #

lastDef :: a -> [a] -> a #

lastMay :: [a] -> Maybe a #

tailDef :: [a] -> [a] -> [a] #

tailMay :: [a] -> Maybe [a] #

NonEmpty

data NonEmpty a #

Non-empty (and non-strict) list type.

Since: base-4.9.0.0

Constructors

a :| [a] infixr 5

Instances

Instances details

Monad NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (>>=) :: NonEmpty a -> (a -> NonEmpty b) -> NonEmpty b # (>>) :: NonEmpty a -> NonEmpty b -> NonEmpty b # return :: a -> NonEmpty a #
Functor NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> NonEmpty a -> NonEmpty b # (<$) :: a -> NonEmpty b -> NonEmpty a #
MonadFix NonEmpty	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> NonEmpty a) -> NonEmpty a #
Applicative NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods pure :: a -> NonEmpty a # (<>) :: NonEmpty (a -> b) -> NonEmpty a -> NonEmpty b # liftA2 :: (a -> b -> c) -> NonEmpty a -> NonEmpty b -> NonEmpty c # (>) :: NonEmpty a -> NonEmpty b -> NonEmpty b # (<*) :: NonEmpty a -> NonEmpty b -> NonEmpty a #
Foldable NonEmpty	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => NonEmpty m -> m # foldMap :: Monoid m => (a -> m) -> NonEmpty a -> m # foldMap' :: Monoid m => (a -> m) -> NonEmpty a -> m # foldr :: (a -> b -> b) -> b -> NonEmpty a -> b # foldr' :: (a -> b -> b) -> b -> NonEmpty a -> b # foldl :: (b -> a -> b) -> b -> NonEmpty a -> b # foldl' :: (b -> a -> b) -> b -> NonEmpty a -> b # foldr1 :: (a -> a -> a) -> NonEmpty a -> a # foldl1 :: (a -> a -> a) -> NonEmpty a -> a # toList :: NonEmpty a -> [a] # null :: NonEmpty a -> Bool # length :: NonEmpty a -> Int # elem :: Eq a => a -> NonEmpty a -> Bool # maximum :: Ord a => NonEmpty a -> a # minimum :: Ord a => NonEmpty a -> a # sum :: Num a => NonEmpty a -> a # product :: Num a => NonEmpty a -> a #
Traversable NonEmpty	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> NonEmpty a -> f (NonEmpty b) # sequenceA :: Applicative f => NonEmpty (f a) -> f (NonEmpty a) # mapM :: Monad m => (a -> m b) -> NonEmpty a -> m (NonEmpty b) # sequence :: Monad m => NonEmpty (m a) -> m (NonEmpty a) #
Eq1 NonEmpty	Since: base-4.10.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> NonEmpty a -> NonEmpty b -> Bool #
Ord1 NonEmpty	Since: base-4.10.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> NonEmpty a -> NonEmpty b -> Ordering #
Read1 NonEmpty	Since: base-4.10.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (NonEmpty a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [NonEmpty a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (NonEmpty a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [NonEmpty a] #
Show1 NonEmpty	Since: base-4.10.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> NonEmpty a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [NonEmpty a] -> ShowS #
IsList (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Exts Associated Types type Item (NonEmpty a) # Methods fromList :: [Item (NonEmpty a)] -> NonEmpty a # fromListN :: Int -> [Item (NonEmpty a)] -> NonEmpty a # toList :: NonEmpty a -> [Item (NonEmpty a)] #
Eq a => Eq (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (==) :: NonEmpty a -> NonEmpty a -> Bool # (/=) :: NonEmpty a -> NonEmpty a -> Bool #
Ord a => Ord (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods compare :: NonEmpty a -> NonEmpty a -> Ordering # (<) :: NonEmpty a -> NonEmpty a -> Bool # (<=) :: NonEmpty a -> NonEmpty a -> Bool # (>) :: NonEmpty a -> NonEmpty a -> Bool # (>=) :: NonEmpty a -> NonEmpty a -> Bool # max :: NonEmpty a -> NonEmpty a -> NonEmpty a # min :: NonEmpty a -> NonEmpty a -> NonEmpty a #
Read a => Read (NonEmpty a)	Since: base-4.11.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (NonEmpty a) # readList :: ReadS [NonEmpty a] # readPrec :: ReadPrec (NonEmpty a) # readListPrec :: ReadPrec [NonEmpty a] #
Show a => Show (NonEmpty a)	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> NonEmpty a -> ShowS # show :: NonEmpty a -> String # showList :: [NonEmpty a] -> ShowS #
Generic (NonEmpty a)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (NonEmpty a) :: Type -> Type # Methods from :: NonEmpty a -> Rep (NonEmpty a) x # to :: Rep (NonEmpty a) x -> NonEmpty a #
Semigroup (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: NonEmpty a -> NonEmpty a -> NonEmpty a # sconcat :: NonEmpty (NonEmpty a) -> NonEmpty a # stimes :: Integral b => b -> NonEmpty a -> NonEmpty a #
Generic1 NonEmpty	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 NonEmpty :: k -> Type # Methods from1 :: forall (a :: k). NonEmpty a -> Rep1 NonEmpty a # to1 :: forall (a :: k). Rep1 NonEmpty a -> NonEmpty a #
type Rep (NonEmpty a)
Instance details Defined in GHC.Generics type Rep (NonEmpty a) = D1 ('MetaData "NonEmpty" "GHC.Base" "base" 'False) (C1 ('MetaCons ":\|" ('InfixI 'LeftAssociative 9) 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [a])))
type Item (NonEmpty a)
Instance details Defined in GHC.Exts type Item (NonEmpty a) = a
type Rep1 NonEmpty
Instance details Defined in GHC.Generics type Rep1 NonEmpty = D1 ('MetaData "NonEmpty" "GHC.Base" "base" 'False) (C1 ('MetaCons ":\|" ('InfixI 'LeftAssociative 9) 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1 :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 [])))

scanl1 :: (a -> a -> a) -> NonEmpty a -> NonEmpty a #

scanl1 is a variant of scanl that has no starting value argument:

scanl1 f [x1, x2, ...] == x1 :| [x1 `f` x2, x1 `f` (x2 `f` x3), ...]

scanr1 :: (a -> a -> a) -> NonEmpty a -> NonEmpty a #

scanr1 is a variant of scanr that has no starting value argument.

head :: NonEmpty a -> a #

Extract the first element of the stream.

init :: NonEmpty a -> [a] #

Extract everything except the last element of the stream.

last :: NonEmpty a -> a #

Extract the last element of the stream.

tail :: NonEmpty a -> [a] #

Extract the possibly-empty tail of the stream.

cycle :: NonEmpty a -> NonEmpty a #

cycle xs returns the infinite repetition of xs:

cycle (1 :| [2,3]) = 1 :| [2,3,1,2,3,...]

Tuple

fst :: (a, b) -> a #

Extract the first component of a pair.

snd :: (a, b) -> b #

Extract the second component of a pair.

curry :: ((a, b) -> c) -> a -> b -> c #

curry converts an uncurried function to a curried function.

Examples

Expand

>>> curry fst 1 2
1

uncurry :: (a -> b -> c) -> (a, b) -> c #

uncurry converts a curried function to a function on pairs.

Examples

Expand

>>> uncurry (+) (1,2)
3

>>> uncurry ($) (show, 1)
"1"

>>> map (uncurry max) [(1,2), (3,4), (6,8)]
[2,4,8]

swap :: (a, b) -> (b, a) #

Swap the components of a pair.

Either

data Either a b #

The Either type represents values with two possibilities: a value of type Either a b is either Left a or Right b.

The Either type is sometimes used to represent a value which is either correct or an error; by convention, the Left constructor is used to hold an error value and the Right constructor is used to hold a correct value (mnemonic: "right" also means "correct").

Examples

Expand

The type Either String Int is the type of values which can be either a String or an Int. The Left constructor can be used only on Strings, and the Right constructor can be used only on Ints:

>>> let s = Left "foo" :: Either String Int
>>> s
Left "foo"
>>> let n = Right 3 :: Either String Int
>>> n
Right 3
>>> :type s
s :: Either String Int
>>> :type n
n :: Either String Int

The fmap from our Functor instance will ignore Left values, but will apply the supplied function to values contained in a Right:

>>> let s = Left "foo" :: Either String Int
>>> let n = Right 3 :: Either String Int
>>> fmap (*2) s
Left "foo"
>>> fmap (*2) n
Right 6

The Monad instance for Either allows us to chain together multiple actions which may fail, and fail overall if any of the individual steps failed. First we'll write a function that can either parse an Int from a Char, or fail.

>>> import Data.Char ( digitToInt, isDigit )
>>> :{
    let parseEither :: Char -> Either String Int
        parseEither c
          | isDigit c = Right (digitToInt c)
          | otherwise = Left "parse error"
>>> :}

The following should work, since both '1' and '2' can be parsed as Ints.

>>> :{
    let parseMultiple :: Either String Int
        parseMultiple = do
          x <- parseEither '1'
          y <- parseEither '2'
          return (x + y)
>>> :}

>>> parseMultiple
Right 3

But the following should fail overall, since the first operation where we attempt to parse 'm' as an Int will fail:

>>> :{
    let parseMultiple :: Either String Int
        parseMultiple = do
          x <- parseEither 'm'
          y <- parseEither '2'
          return (x + y)
>>> :}

>>> parseMultiple
Left "parse error"

Constructors

Left a
Right b

Instances

Instances details

Bitraversable Either	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Either a b -> f (Either c d) #
Bifoldable Either	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => Either m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Either a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Either a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Either a b -> c #
Bifunctor Either	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> Either a c -> Either b d # first :: (a -> b) -> Either a c -> Either b c # second :: (b -> c) -> Either a b -> Either a c #
Eq2 Either	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Either a c -> Either b d -> Bool #
Ord2 Either	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Either a c -> Either b d -> Ordering #
Read2 Either	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Either a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Either a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Either a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Either a b] #
Show2 Either	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Either a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Either a b] -> ShowS #
Monad (Either e)	Since: base-4.4.0.0
Instance details Defined in Data.Either Methods (>>=) :: Either e a -> (a -> Either e b) -> Either e b # (>>) :: Either e a -> Either e b -> Either e b # return :: a -> Either e a #
Functor (Either a)	Since: base-3.0
Instance details Defined in Data.Either Methods fmap :: (a0 -> b) -> Either a a0 -> Either a b # (<$) :: a0 -> Either a b -> Either a a0 #
MonadFix (Either e)	Since: base-4.3.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Either e a) -> Either e a #
Applicative (Either e)	Since: base-3.0
Instance details Defined in Data.Either Methods pure :: a -> Either e a # (<>) :: Either e (a -> b) -> Either e a -> Either e b # liftA2 :: (a -> b -> c) -> Either e a -> Either e b -> Either e c # (>) :: Either e a -> Either e b -> Either e b # (<*) :: Either e a -> Either e b -> Either e a #
Foldable (Either a)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Either a m -> m # foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # toList :: Either a a0 -> [a0] # null :: Either a a0 -> Bool # length :: Either a a0 -> Int # elem :: Eq a0 => a0 -> Either a a0 -> Bool # maximum :: Ord a0 => Either a a0 -> a0 # minimum :: Ord a0 => Either a a0 -> a0 # sum :: Num a0 => Either a a0 -> a0 # product :: Num a0 => Either a a0 -> a0 #
Traversable (Either a)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a0 -> f b) -> Either a a0 -> f (Either a b) # sequenceA :: Applicative f => Either a (f a0) -> f (Either a a0) # mapM :: Monad m => (a0 -> m b) -> Either a a0 -> m (Either a b) # sequence :: Monad m => Either a (m a0) -> m (Either a a0) #
Eq a => Eq1 (Either a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a0 -> b -> Bool) -> Either a a0 -> Either a b -> Bool #
Ord a => Ord1 (Either a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a0 -> b -> Ordering) -> Either a a0 -> Either a b -> Ordering #
Read a => Read1 (Either a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Either a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Either a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Either a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Either a a0] #
Show a => Show1 (Either a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> Either a a0 -> ShowS # liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [Either a a0] -> ShowS #
Generic1 (Either a :: Type -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (Either a) :: k -> Type # Methods from1 :: forall (a0 :: k). Either a a0 -> Rep1 (Either a) a0 # to1 :: forall (a0 :: k). Rep1 (Either a) a0 -> Either a a0 #
(Eq a, Eq b) => Eq (Either a b)	Since: base-2.1
Instance details Defined in Data.Either Methods (==) :: Either a b -> Either a b -> Bool # (/=) :: Either a b -> Either a b -> Bool #
(Ord a, Ord b) => Ord (Either a b)	Since: base-2.1
Instance details Defined in Data.Either Methods compare :: Either a b -> Either a b -> Ordering # (<) :: Either a b -> Either a b -> Bool # (<=) :: Either a b -> Either a b -> Bool # (>) :: Either a b -> Either a b -> Bool # (>=) :: Either a b -> Either a b -> Bool # max :: Either a b -> Either a b -> Either a b # min :: Either a b -> Either a b -> Either a b #
(Read a, Read b) => Read (Either a b)	Since: base-3.0
Instance details Defined in Data.Either Methods readsPrec :: Int -> ReadS (Either a b) # readList :: ReadS [Either a b] # readPrec :: ReadPrec (Either a b) # readListPrec :: ReadPrec [Either a b] #
(Show a, Show b) => Show (Either a b)	Since: base-3.0
Instance details Defined in Data.Either Methods showsPrec :: Int -> Either a b -> ShowS # show :: Either a b -> String # showList :: [Either a b] -> ShowS #
Generic (Either a b)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Either a b) :: Type -> Type # Methods from :: Either a b -> Rep (Either a b) x # to :: Rep (Either a b) x -> Either a b #
Semigroup (Either a b)	Since: base-4.9.0.0
Instance details Defined in Data.Either Methods (<>) :: Either a b -> Either a b -> Either a b # sconcat :: NonEmpty (Either a b) -> Either a b # stimes :: Integral b0 => b0 -> Either a b -> Either a b #
type Rep1 (Either a :: Type -> Type)
Instance details Defined in GHC.Generics type Rep1 (Either a :: Type -> Type) = D1 ('MetaData "Either" "Data.Either" "base" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))
type Rep (Either a b)
Instance details Defined in GHC.Generics type Rep (Either a b) = D1 ('MetaData "Either" "Data.Either" "base" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 b)))

either :: (a -> c) -> (b -> c) -> Either a b -> c #

Case analysis for the Either type. If the value is Left a, apply the first function to a; if it is Right b, apply the second function to b.

Examples

Expand

We create two values of type Either String Int, one using the Left constructor and another using the Right constructor. Then we apply "either" the length function (if we have a String) or the "times-two" function (if we have an Int):

>>> let s = Left "foo" :: Either String Int
>>> let n = Right 3 :: Either String Int
>>> either length (*2) s
3
>>> either length (*2) n
6

fromLeft :: a -> Either a b -> a #

Return the contents of a Left-value or a default value otherwise.

Examples

Expand

Basic usage:

>>> fromLeft 1 (Left 3)
3
>>> fromLeft 1 (Right "foo")
1

Since: base-4.10.0.0

fromRight :: b -> Either a b -> b #

Return the contents of a Right-value or a default value otherwise.

Examples

Expand

Basic usage:

>>> fromRight 1 (Right 3)
3
>>> fromRight 1 (Left "foo")
1

Since: base-4.10.0.0

isLeft :: Either a b -> Bool #

Return True if the given value is a Left-value, False otherwise.

Examples

Expand

Basic usage:

>>> isLeft (Left "foo")
True
>>> isLeft (Right 3)
False

Assuming a Left value signifies some sort of error, we can use isLeft to write a very simple error-reporting function that does absolutely nothing in the case of success, and outputs "ERROR" if any error occurred.

This example shows how isLeft might be used to avoid pattern matching when one does not care about the value contained in the constructor:

>>> import Control.Monad ( when )
>>> let report e = when (isLeft e) $ putStrLn "ERROR"
>>> report (Right 1)
>>> report (Left "parse error")
ERROR

Since: base-4.7.0.0

isRight :: Either a b -> Bool #

Return True if the given value is a Right-value, False otherwise.

Examples

Expand

Basic usage:

>>> isRight (Left "foo")
False
>>> isRight (Right 3)
True

Assuming a Left value signifies some sort of error, we can use isRight to write a very simple reporting function that only outputs "SUCCESS" when a computation has succeeded.

This example shows how isRight might be used to avoid pattern matching when one does not care about the value contained in the constructor:

>>> import Control.Monad ( when )
>>> let report e = when (isRight e) $ putStrLn "SUCCESS"
>>> report (Left "parse error")
>>> report (Right 1)
SUCCESS

Since: base-4.7.0.0

lefts :: [Either a b] -> [a] #

Extracts from a list of Either all the Left elements. All the Left elements are extracted in order.

Examples

Expand

Basic usage:

>>> let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]
>>> lefts list
["foo","bar","baz"]

rights :: [Either a b] -> [b] #

Extracts from a list of Either all the Right elements. All the Right elements are extracted in order.

Examples

Expand

Basic usage:

>>> let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]
>>> rights list
[3,7]

partitionEithers :: [Either a b] -> ([a], [b]) #

Partitions a list of Either into two lists. All the Left elements are extracted, in order, to the first component of the output. Similarly the Right elements are extracted to the second component of the output.

Examples

Expand

Basic usage:

>>> let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]
>>> partitionEithers list
(["foo","bar","baz"],[3,7])

The pair returned by partitionEithers x should be the same pair as (lefts x, rights x):

>>> let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]
>>> partitionEithers list == (lefts list, rights list)
True

eitherToMaybe :: Either a b -> Maybe b #

maybeToEither :: a -> Maybe b -> Either a b #

Text types

Char and String

data Char #

The character type Char is an enumeration whose values represent Unicode (or equivalently ISO/IEC 10646) code points (i.e. characters, see http://www.unicode.org/ for details). This set extends the ISO 8859-1 (Latin-1) character set (the first 256 characters), which is itself an extension of the ASCII character set (the first 128 characters). A character literal in Haskell has type Char.

To convert a Char to or from the corresponding Int value defined by Unicode, use toEnum and fromEnum from the Enum class respectively (or equivalently ord and chr).

Instances

Instances details

Bounded Char	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Char # maxBound :: Char #
Enum Char	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Char -> Char # pred :: Char -> Char # toEnum :: Int -> Char # fromEnum :: Char -> Int # enumFrom :: Char -> [Char] # enumFromThen :: Char -> Char -> [Char] # enumFromTo :: Char -> Char -> [Char] # enumFromThenTo :: Char -> Char -> Char -> [Char] #
Eq Char
Instance details Defined in GHC.Classes Methods (==) :: Char -> Char -> Bool # (/=) :: Char -> Char -> Bool #
Ord Char
Instance details Defined in GHC.Classes Methods compare :: Char -> Char -> Ordering # (<) :: Char -> Char -> Bool # (<=) :: Char -> Char -> Bool # (>) :: Char -> Char -> Bool # (>=) :: Char -> Char -> Bool # max :: Char -> Char -> Char # min :: Char -> Char -> Char #
Read Char	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Char # readList :: ReadS [Char] # readPrec :: ReadPrec Char # readListPrec :: ReadPrec [Char] #
Show Char	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Char -> ShowS # show :: Char -> String # showList :: [Char] -> ShowS #
ErrorList Char
Instance details Defined in Control.Monad.Trans.Error Methods listMsg :: String -> [Char] #
StringConv String String Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> String -> String Source #
StringConv String ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> String -> ByteString Source #
StringConv String ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> String -> ByteString Source #
StringConv String Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> String -> Text Source #
StringConv String Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> String -> Text Source #
StringConv ByteString String Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString -> String Source #
StringConv ByteString String Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString -> String Source #
StringConv Text String Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text -> String Source #
StringConv Text String Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text -> String Source #
Generic1 (URec Char :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Char) :: k -> Type # Methods from1 :: forall (a :: k0). URec Char a -> Rep1 (URec Char) a # to1 :: forall (a :: k0). Rep1 (URec Char) a -> URec Char a #
Foldable (UChar :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UChar m -> m # foldMap :: Monoid m => (a -> m) -> UChar a -> m # foldMap' :: Monoid m => (a -> m) -> UChar a -> m # foldr :: (a -> b -> b) -> b -> UChar a -> b # foldr' :: (a -> b -> b) -> b -> UChar a -> b # foldl :: (b -> a -> b) -> b -> UChar a -> b # foldl' :: (b -> a -> b) -> b -> UChar a -> b # foldr1 :: (a -> a -> a) -> UChar a -> a # foldl1 :: (a -> a -> a) -> UChar a -> a # toList :: UChar a -> [a] # null :: UChar a -> Bool # length :: UChar a -> Int # elem :: Eq a => a -> UChar a -> Bool # maximum :: Ord a => UChar a -> a # minimum :: Ord a => UChar a -> a # sum :: Num a => UChar a -> a # product :: Num a => UChar a -> a #
Traversable (UChar :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UChar a -> f (UChar b) # sequenceA :: Applicative f => UChar (f a) -> f (UChar a) # mapM :: Monad m => (a -> m b) -> UChar a -> m (UChar b) # sequence :: Monad m => UChar (m a) -> m (UChar a) #
Print [Char] Source #
Instance details Defined in Verset Methods hPutStr :: MonadIO m => Handle -> [Char] -> m () Source # putStr :: MonadIO m => [Char] -> m () Source # hPutStrLn :: MonadIO m => Handle -> [Char] -> m () Source # putStrLn :: MonadIO m => [Char] -> m () Source # putErrLn :: MonadIO m => [Char] -> m () Source #
Functor (URec Char :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods fmap :: (a -> b) -> URec Char a -> URec Char b # (<$) :: a -> URec Char b -> URec Char a #
Eq (URec Char p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: URec Char p -> URec Char p -> Bool # (/=) :: URec Char p -> URec Char p -> Bool #
Ord (URec Char p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: URec Char p -> URec Char p -> Ordering # (<) :: URec Char p -> URec Char p -> Bool # (<=) :: URec Char p -> URec Char p -> Bool # (>) :: URec Char p -> URec Char p -> Bool # (>=) :: URec Char p -> URec Char p -> Bool # max :: URec Char p -> URec Char p -> URec Char p # min :: URec Char p -> URec Char p -> URec Char p #
Show (URec Char p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Char p -> ShowS # show :: URec Char p -> String # showList :: [URec Char p] -> ShowS #
Generic (URec Char p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (URec Char p) :: Type -> Type # Methods from :: URec Char p -> Rep (URec Char p) x # to :: Rep (URec Char p) x -> URec Char p #
data URec Char (p :: k)	Used for marking occurrences of `Char#` Since: base-4.9.0.0
Instance details Defined in GHC.Generics data URec Char (p :: k) = UChar { uChar# :: Char# }
type Rep1 (URec Char :: k -> Type)
Instance details Defined in GHC.Generics type Rep1 (URec Char :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UChar" 'PrefixI 'True) (S1 ('MetaSel ('Just "uChar#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UChar :: k -> Type)))
type Rep (URec Char p)
Instance details Defined in GHC.Generics type Rep (URec Char p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UChar" 'PrefixI 'True) (S1 ('MetaSel ('Just "uChar#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UChar :: Type -> Type)))

String conversion

class IsString a where #

Class for string-like datastructures; used by the overloaded string extension (-XOverloadedStrings in GHC).

Methods

fromString :: String -> a #

Instances

Instances details

IsString ByteString	Beware: `fromString` truncates multi-byte characters to octets. e.g. "枯朶に烏のとまりけり秋の暮" becomes �6k�nh~�Q��n�
Instance details Defined in Data.ByteString.Lazy.Internal Methods fromString :: String -> ByteString #
IsString ByteString	Beware: `fromString` truncates multi-byte characters to octets. e.g. "枯朶に烏のとまりけり秋の暮" becomes �6k�nh~�Q��n�
Instance details Defined in Data.ByteString.Internal Methods fromString :: String -> ByteString #
a ~ Char => IsString [a]	`(a ~ Char)` context was introduced in `4.9.0.0` Since: base-2.1
Instance details Defined in Data.String Methods fromString :: String -> [a] #
IsString a => IsString (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.String Methods fromString :: String -> Identity a #
IsString a => IsString (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.String Methods fromString :: String -> Const a b #

Container types

Map and Set (Ordered)

data Map k a #

A Map from keys k to values a.

The Semigroup operation for Map is union, which prefers values from the left operand. If m1 maps a key k to a value a1, and m2 maps the same key to a different value a2, then their union m1 <> m2 maps k to a1.

Instances

Instances details

Bifoldable Map	Since: containers-0.6.3.1
Instance details Defined in Data.Map.Internal Methods bifold :: Monoid m => Map m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Map a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Map a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Map a b -> c #
Eq2 Map	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Map a c -> Map b d -> Bool #
Ord2 Map	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Map a c -> Map b d -> Ordering #
Show2 Map	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Map a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Map a b] -> ShowS #
Functor (Map k)
Instance details Defined in Data.Map.Internal Methods fmap :: (a -> b) -> Map k a -> Map k b # (<$) :: a -> Map k b -> Map k a #
Foldable (Map k)	Folds in order of increasing key.
Instance details Defined in Data.Map.Internal Methods fold :: Monoid m => Map k m -> m # foldMap :: Monoid m => (a -> m) -> Map k a -> m # foldMap' :: Monoid m => (a -> m) -> Map k a -> m # foldr :: (a -> b -> b) -> b -> Map k a -> b # foldr' :: (a -> b -> b) -> b -> Map k a -> b # foldl :: (b -> a -> b) -> b -> Map k a -> b # foldl' :: (b -> a -> b) -> b -> Map k a -> b # foldr1 :: (a -> a -> a) -> Map k a -> a # foldl1 :: (a -> a -> a) -> Map k a -> a # toList :: Map k a -> [a] # null :: Map k a -> Bool # length :: Map k a -> Int # elem :: Eq a => a -> Map k a -> Bool # maximum :: Ord a => Map k a -> a # minimum :: Ord a => Map k a -> a # sum :: Num a => Map k a -> a # product :: Num a => Map k a -> a #
Traversable (Map k)	Traverses in order of increasing key.
Instance details Defined in Data.Map.Internal Methods traverse :: Applicative f => (a -> f b) -> Map k a -> f (Map k b) # sequenceA :: Applicative f => Map k (f a) -> f (Map k a) # mapM :: Monad m => (a -> m b) -> Map k a -> m (Map k b) # sequence :: Monad m => Map k (m a) -> m (Map k a) #
Eq k => Eq1 (Map k)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftEq :: (a -> b -> Bool) -> Map k a -> Map k b -> Bool #
Ord k => Ord1 (Map k)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftCompare :: (a -> b -> Ordering) -> Map k a -> Map k b -> Ordering #
(Ord k, Read k) => Read1 (Map k)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Map k a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Map k a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Map k a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Map k a] #
Show k => Show1 (Map k)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Map k a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Map k a] -> ShowS #
Ord k => IsList (Map k v)	Since: containers-0.5.6.2
Instance details Defined in Data.Map.Internal Associated Types type Item (Map k v) # Methods fromList :: [Item (Map k v)] -> Map k v # fromListN :: Int -> [Item (Map k v)] -> Map k v # toList :: Map k v -> [Item (Map k v)] #
(Eq k, Eq a) => Eq (Map k a)
Instance details Defined in Data.Map.Internal Methods (==) :: Map k a -> Map k a -> Bool # (/=) :: Map k a -> Map k a -> Bool #
(Data k, Data a, Ord k) => Data (Map k a)
Instance details Defined in Data.Map.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Map k a -> c (Map k a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Map k a) # toConstr :: Map k a -> Constr # dataTypeOf :: Map k a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Map k a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Map k a)) # gmapT :: (forall b. Data b => b -> b) -> Map k a -> Map k a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Map k a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Map k a -> r # gmapQ :: (forall d. Data d => d -> u) -> Map k a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Map k a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Map k a -> m (Map k a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Map k a -> m (Map k a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Map k a -> m (Map k a) #
(Ord k, Ord v) => Ord (Map k v)
Instance details Defined in Data.Map.Internal Methods compare :: Map k v -> Map k v -> Ordering # (<) :: Map k v -> Map k v -> Bool # (<=) :: Map k v -> Map k v -> Bool # (>) :: Map k v -> Map k v -> Bool # (>=) :: Map k v -> Map k v -> Bool # max :: Map k v -> Map k v -> Map k v # min :: Map k v -> Map k v -> Map k v #
(Ord k, Read k, Read e) => Read (Map k e)
Instance details Defined in Data.Map.Internal Methods readsPrec :: Int -> ReadS (Map k e) # readList :: ReadS [Map k e] # readPrec :: ReadPrec (Map k e) # readListPrec :: ReadPrec [Map k e] #
(Show k, Show a) => Show (Map k a)
Instance details Defined in Data.Map.Internal Methods showsPrec :: Int -> Map k a -> ShowS # show :: Map k a -> String # showList :: [Map k a] -> ShowS #
Ord k => Semigroup (Map k v)
Instance details Defined in Data.Map.Internal Methods (<>) :: Map k v -> Map k v -> Map k v # sconcat :: NonEmpty (Map k v) -> Map k v # stimes :: Integral b => b -> Map k v -> Map k v #
Ord k => Monoid (Map k v)
Instance details Defined in Data.Map.Internal Methods mempty :: Map k v # mappend :: Map k v -> Map k v -> Map k v # mconcat :: [Map k v] -> Map k v #
(NFData k, NFData a) => NFData (Map k a)
Instance details Defined in Data.Map.Internal Methods rnf :: Map k a -> () #
type Item (Map k v)
Instance details Defined in Data.Map.Internal type Item (Map k v) = (k, v)

data Set a #

A set of values a.

Instances

Instances details

Foldable Set	Folds in order of increasing key.
Instance details Defined in Data.Set.Internal Methods fold :: Monoid m => Set m -> m # foldMap :: Monoid m => (a -> m) -> Set a -> m # foldMap' :: Monoid m => (a -> m) -> Set a -> m # foldr :: (a -> b -> b) -> b -> Set a -> b # foldr' :: (a -> b -> b) -> b -> Set a -> b # foldl :: (b -> a -> b) -> b -> Set a -> b # foldl' :: (b -> a -> b) -> b -> Set a -> b # foldr1 :: (a -> a -> a) -> Set a -> a # foldl1 :: (a -> a -> a) -> Set a -> a # toList :: Set a -> [a] # null :: Set a -> Bool # length :: Set a -> Int # elem :: Eq a => a -> Set a -> Bool # maximum :: Ord a => Set a -> a # minimum :: Ord a => Set a -> a # sum :: Num a => Set a -> a # product :: Num a => Set a -> a #
Eq1 Set	Since: containers-0.5.9
Instance details Defined in Data.Set.Internal Methods liftEq :: (a -> b -> Bool) -> Set a -> Set b -> Bool #
Ord1 Set	Since: containers-0.5.9
Instance details Defined in Data.Set.Internal Methods liftCompare :: (a -> b -> Ordering) -> Set a -> Set b -> Ordering #
Show1 Set	Since: containers-0.5.9
Instance details Defined in Data.Set.Internal Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Set a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Set a] -> ShowS #
Ord a => IsList (Set a)	Since: containers-0.5.6.2
Instance details Defined in Data.Set.Internal Associated Types type Item (Set a) # Methods fromList :: [Item (Set a)] -> Set a # fromListN :: Int -> [Item (Set a)] -> Set a # toList :: Set a -> [Item (Set a)] #
Eq a => Eq (Set a)
Instance details Defined in Data.Set.Internal Methods (==) :: Set a -> Set a -> Bool # (/=) :: Set a -> Set a -> Bool #
(Data a, Ord a) => Data (Set a)
Instance details Defined in Data.Set.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Set a -> c (Set a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Set a) # toConstr :: Set a -> Constr # dataTypeOf :: Set a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Set a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Set a)) # gmapT :: (forall b. Data b => b -> b) -> Set a -> Set a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r # gmapQ :: (forall d. Data d => d -> u) -> Set a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Set a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) #
Ord a => Ord (Set a)
Instance details Defined in Data.Set.Internal Methods compare :: Set a -> Set a -> Ordering # (<) :: Set a -> Set a -> Bool # (<=) :: Set a -> Set a -> Bool # (>) :: Set a -> Set a -> Bool # (>=) :: Set a -> Set a -> Bool # max :: Set a -> Set a -> Set a # min :: Set a -> Set a -> Set a #
(Read a, Ord a) => Read (Set a)
Instance details Defined in Data.Set.Internal Methods readsPrec :: Int -> ReadS (Set a) # readList :: ReadS [Set a] # readPrec :: ReadPrec (Set a) # readListPrec :: ReadPrec [Set a] #
Show a => Show (Set a)
Instance details Defined in Data.Set.Internal Methods showsPrec :: Int -> Set a -> ShowS # show :: Set a -> String # showList :: [Set a] -> ShowS #
Ord a => Semigroup (Set a)	Since: containers-0.5.7
Instance details Defined in Data.Set.Internal Methods (<>) :: Set a -> Set a -> Set a # sconcat :: NonEmpty (Set a) -> Set a # stimes :: Integral b => b -> Set a -> Set a #
Ord a => Monoid (Set a)
Instance details Defined in Data.Set.Internal Methods mempty :: Set a # mappend :: Set a -> Set a -> Set a # mconcat :: [Set a] -> Set a #
NFData a => NFData (Set a)
Instance details Defined in Data.Set.Internal Methods rnf :: Set a -> () #
type Item (Set a)
Instance details Defined in Data.Set.Internal type Item (Set a) = a

Seq

Numeric types

Big integers

data Integer #

Arbitrary precision integers. In contrast with fixed-size integral types such as Int, the Integer type represents the entire infinite range of integers.

For more information about this type's representation, see the comments in its implementation.

Instances

Instances details

Enum Integer	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Integer -> Integer # pred :: Integer -> Integer # toEnum :: Int -> Integer # fromEnum :: Integer -> Int # enumFrom :: Integer -> [Integer] # enumFromThen :: Integer -> Integer -> [Integer] # enumFromTo :: Integer -> Integer -> [Integer] # enumFromThenTo :: Integer -> Integer -> Integer -> [Integer] #
Eq Integer
Instance details Defined in GHC.Integer.Type Methods (==) :: Integer -> Integer -> Bool # (/=) :: Integer -> Integer -> Bool #
Integral Integer	Since: base-2.0.1
Instance details Defined in GHC.Real Methods quot :: Integer -> Integer -> Integer # rem :: Integer -> Integer -> Integer # div :: Integer -> Integer -> Integer # mod :: Integer -> Integer -> Integer # quotRem :: Integer -> Integer -> (Integer, Integer) # divMod :: Integer -> Integer -> (Integer, Integer) # toInteger :: Integer -> Integer #
Num Integer	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Integer -> Integer -> Integer # (-) :: Integer -> Integer -> Integer # (*) :: Integer -> Integer -> Integer # negate :: Integer -> Integer # abs :: Integer -> Integer # signum :: Integer -> Integer # fromInteger :: Integer -> Integer #
Ord Integer
Instance details Defined in GHC.Integer.Type Methods compare :: Integer -> Integer -> Ordering # (<) :: Integer -> Integer -> Bool # (<=) :: Integer -> Integer -> Bool # (>) :: Integer -> Integer -> Bool # (>=) :: Integer -> Integer -> Bool # max :: Integer -> Integer -> Integer # min :: Integer -> Integer -> Integer #
Read Integer	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Integer # readList :: ReadS [Integer] # readPrec :: ReadPrec Integer # readListPrec :: ReadPrec [Integer] #
Real Integer	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Integer -> Rational #
Show Integer	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Integer -> ShowS # show :: Integer -> String # showList :: [Integer] -> ShowS #
Bits Integer	Since: base-2.1
Instance details Defined in Data.Bits Methods (.&.) :: Integer -> Integer -> Integer # (.\|.) :: Integer -> Integer -> Integer # xor :: Integer -> Integer -> Integer # complement :: Integer -> Integer # shift :: Integer -> Int -> Integer # rotate :: Integer -> Int -> Integer # zeroBits :: Integer # bit :: Int -> Integer # setBit :: Integer -> Int -> Integer # clearBit :: Integer -> Int -> Integer # complementBit :: Integer -> Int -> Integer # testBit :: Integer -> Int -> Bool # bitSizeMaybe :: Integer -> Maybe Int # bitSize :: Integer -> Int # isSigned :: Integer -> Bool # shiftL :: Integer -> Int -> Integer # unsafeShiftL :: Integer -> Int -> Integer # shiftR :: Integer -> Int -> Integer # unsafeShiftR :: Integer -> Int -> Integer # rotateL :: Integer -> Int -> Integer # rotateR :: Integer -> Int -> Integer # popCount :: Integer -> Int #

data Natural #

Type representing arbitrary-precision non-negative integers.

>>> 2^100 :: Natural
1267650600228229401496703205376

Operations whose result would be negative throw (Underflow :: ArithException),

>>> -1 :: Natural
*** Exception: arithmetic underflow

Since: base-4.8.0.0

Instances

Instances details

Enum Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Enum Methods succ :: Natural -> Natural # pred :: Natural -> Natural # toEnum :: Int -> Natural # fromEnum :: Natural -> Int # enumFrom :: Natural -> [Natural] # enumFromThen :: Natural -> Natural -> [Natural] # enumFromTo :: Natural -> Natural -> [Natural] # enumFromThenTo :: Natural -> Natural -> Natural -> [Natural] #
Eq Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Natural Methods (==) :: Natural -> Natural -> Bool # (/=) :: Natural -> Natural -> Bool #
Integral Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Real Methods quot :: Natural -> Natural -> Natural # rem :: Natural -> Natural -> Natural # div :: Natural -> Natural -> Natural # mod :: Natural -> Natural -> Natural # quotRem :: Natural -> Natural -> (Natural, Natural) # divMod :: Natural -> Natural -> (Natural, Natural) # toInteger :: Natural -> Integer #
Num Natural	Note that `Natural`'s `Num` instance isn't a ring: no element but 0 has an additive inverse. It is a semiring though. Since: base-4.8.0.0
Instance details Defined in GHC.Num Methods (+) :: Natural -> Natural -> Natural # (-) :: Natural -> Natural -> Natural # (*) :: Natural -> Natural -> Natural # negate :: Natural -> Natural # abs :: Natural -> Natural # signum :: Natural -> Natural # fromInteger :: Integer -> Natural #
Ord Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Natural Methods compare :: Natural -> Natural -> Ordering # (<) :: Natural -> Natural -> Bool # (<=) :: Natural -> Natural -> Bool # (>) :: Natural -> Natural -> Bool # (>=) :: Natural -> Natural -> Bool # max :: Natural -> Natural -> Natural # min :: Natural -> Natural -> Natural #
Read Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Natural # readList :: ReadS [Natural] # readPrec :: ReadPrec Natural # readListPrec :: ReadPrec [Natural] #
Real Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Real Methods toRational :: Natural -> Rational #
Show Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Natural -> ShowS # show :: Natural -> String # showList :: [Natural] -> ShowS #
Bits Natural	Since: base-4.8.0
Instance details Defined in Data.Bits Methods (.&.) :: Natural -> Natural -> Natural # (.\|.) :: Natural -> Natural -> Natural # xor :: Natural -> Natural -> Natural # complement :: Natural -> Natural # shift :: Natural -> Int -> Natural # rotate :: Natural -> Int -> Natural # zeroBits :: Natural # bit :: Int -> Natural # setBit :: Natural -> Int -> Natural # clearBit :: Natural -> Int -> Natural # complementBit :: Natural -> Int -> Natural # testBit :: Natural -> Int -> Bool # bitSizeMaybe :: Natural -> Maybe Int # bitSize :: Natural -> Int # isSigned :: Natural -> Bool # shiftL :: Natural -> Int -> Natural # unsafeShiftL :: Natural -> Int -> Natural # shiftR :: Natural -> Int -> Natural # unsafeShiftR :: Natural -> Int -> Natural # rotateL :: Natural -> Int -> Natural # rotateR :: Natural -> Int -> Natural # popCount :: Natural -> Int #

Small integers

data Int #

A fixed-precision integer type with at least the range [-2^29 .. 2^29-1]. The exact range for a given implementation can be determined by using minBound and maxBound from the Bounded class.

Instances

Instances details

Bounded Int	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Int # maxBound :: Int #
Enum Int	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Int -> Int # pred :: Int -> Int # toEnum :: Int -> Int # fromEnum :: Int -> Int # enumFrom :: Int -> [Int] # enumFromThen :: Int -> Int -> [Int] # enumFromTo :: Int -> Int -> [Int] # enumFromThenTo :: Int -> Int -> Int -> [Int] #
Eq Int
Instance details Defined in GHC.Classes Methods (==) :: Int -> Int -> Bool # (/=) :: Int -> Int -> Bool #
Integral Int	Since: base-2.0.1
Instance details Defined in GHC.Real Methods quot :: Int -> Int -> Int # rem :: Int -> Int -> Int # div :: Int -> Int -> Int # mod :: Int -> Int -> Int # quotRem :: Int -> Int -> (Int, Int) # divMod :: Int -> Int -> (Int, Int) # toInteger :: Int -> Integer #
Num Int	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Int -> Int -> Int # (-) :: Int -> Int -> Int # (*) :: Int -> Int -> Int # negate :: Int -> Int # abs :: Int -> Int # signum :: Int -> Int # fromInteger :: Integer -> Int #
Ord Int
Instance details Defined in GHC.Classes Methods compare :: Int -> Int -> Ordering # (<) :: Int -> Int -> Bool # (<=) :: Int -> Int -> Bool # (>) :: Int -> Int -> Bool # (>=) :: Int -> Int -> Bool # max :: Int -> Int -> Int # min :: Int -> Int -> Int #
Read Int	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Int # readList :: ReadS [Int] # readPrec :: ReadPrec Int # readListPrec :: ReadPrec [Int] #
Real Int	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Int -> Rational #
Show Int	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Int -> ShowS # show :: Int -> String # showList :: [Int] -> ShowS #
Bits Int	Since: base-2.1
Instance details Defined in Data.Bits Methods (.&.) :: Int -> Int -> Int # (.\|.) :: Int -> Int -> Int # xor :: Int -> Int -> Int # complement :: Int -> Int # shift :: Int -> Int -> Int # rotate :: Int -> Int -> Int # zeroBits :: Int # bit :: Int -> Int # setBit :: Int -> Int -> Int # clearBit :: Int -> Int -> Int # complementBit :: Int -> Int -> Int # testBit :: Int -> Int -> Bool # bitSizeMaybe :: Int -> Maybe Int # bitSize :: Int -> Int # isSigned :: Int -> Bool # shiftL :: Int -> Int -> Int # unsafeShiftL :: Int -> Int -> Int # shiftR :: Int -> Int -> Int # unsafeShiftR :: Int -> Int -> Int # rotateL :: Int -> Int -> Int # rotateR :: Int -> Int -> Int # popCount :: Int -> Int #
FiniteBits Int	Since: base-4.6.0.0
Instance details Defined in Data.Bits Methods finiteBitSize :: Int -> Int # countLeadingZeros :: Int -> Int # countTrailingZeros :: Int -> Int #
Generic1 (URec Int :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Int) :: k -> Type # Methods from1 :: forall (a :: k0). URec Int a -> Rep1 (URec Int) a # to1 :: forall (a :: k0). Rep1 (URec Int) a -> URec Int a #
Foldable (UInt :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UInt m -> m # foldMap :: Monoid m => (a -> m) -> UInt a -> m # foldMap' :: Monoid m => (a -> m) -> UInt a -> m # foldr :: (a -> b -> b) -> b -> UInt a -> b # foldr' :: (a -> b -> b) -> b -> UInt a -> b # foldl :: (b -> a -> b) -> b -> UInt a -> b # foldl' :: (b -> a -> b) -> b -> UInt a -> b # foldr1 :: (a -> a -> a) -> UInt a -> a # foldl1 :: (a -> a -> a) -> UInt a -> a # toList :: UInt a -> [a] # null :: UInt a -> Bool # length :: UInt a -> Int # elem :: Eq a => a -> UInt a -> Bool # maximum :: Ord a => UInt a -> a # minimum :: Ord a => UInt a -> a # sum :: Num a => UInt a -> a # product :: Num a => UInt a -> a #
Traversable (UInt :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UInt a -> f (UInt b) # sequenceA :: Applicative f => UInt (f a) -> f (UInt a) # mapM :: Monad m => (a -> m b) -> UInt a -> m (UInt b) # sequence :: Monad m => UInt (m a) -> m (UInt a) #
Functor (URec Int :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods fmap :: (a -> b) -> URec Int a -> URec Int b # (<$) :: a -> URec Int b -> URec Int a #
Eq (URec Int p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: URec Int p -> URec Int p -> Bool # (/=) :: URec Int p -> URec Int p -> Bool #
Ord (URec Int p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: URec Int p -> URec Int p -> Ordering # (<) :: URec Int p -> URec Int p -> Bool # (<=) :: URec Int p -> URec Int p -> Bool # (>) :: URec Int p -> URec Int p -> Bool # (>=) :: URec Int p -> URec Int p -> Bool # max :: URec Int p -> URec Int p -> URec Int p # min :: URec Int p -> URec Int p -> URec Int p #
Show (URec Int p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Int p -> ShowS # show :: URec Int p -> String # showList :: [URec Int p] -> ShowS #
Generic (URec Int p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (URec Int p) :: Type -> Type # Methods from :: URec Int p -> Rep (URec Int p) x # to :: Rep (URec Int p) x -> URec Int p #
data URec Int (p :: k)	Used for marking occurrences of `Int#` Since: base-4.9.0.0
Instance details Defined in GHC.Generics data URec Int (p :: k) = UInt { uInt# :: Int# }
type Rep1 (URec Int :: k -> Type)
Instance details Defined in GHC.Generics type Rep1 (URec Int :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UInt" 'PrefixI 'True) (S1 ('MetaSel ('Just "uInt#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UInt :: k -> Type)))
type Rep (URec Int p)
Instance details Defined in GHC.Generics type Rep (URec Int p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UInt" 'PrefixI 'True) (S1 ('MetaSel ('Just "uInt#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UInt :: Type -> Type)))

data Int16 #

16-bit signed integer type

Instances

Instances details

Bounded Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods minBound :: Int16 # maxBound :: Int16 #
Enum Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods succ :: Int16 -> Int16 # pred :: Int16 -> Int16 # toEnum :: Int -> Int16 # fromEnum :: Int16 -> Int # enumFrom :: Int16 -> [Int16] # enumFromThen :: Int16 -> Int16 -> [Int16] # enumFromTo :: Int16 -> Int16 -> [Int16] # enumFromThenTo :: Int16 -> Int16 -> Int16 -> [Int16] #
Eq Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods (==) :: Int16 -> Int16 -> Bool # (/=) :: Int16 -> Int16 -> Bool #
Integral Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods quot :: Int16 -> Int16 -> Int16 # rem :: Int16 -> Int16 -> Int16 # div :: Int16 -> Int16 -> Int16 # mod :: Int16 -> Int16 -> Int16 # quotRem :: Int16 -> Int16 -> (Int16, Int16) # divMod :: Int16 -> Int16 -> (Int16, Int16) # toInteger :: Int16 -> Integer #
Num Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods (+) :: Int16 -> Int16 -> Int16 # (-) :: Int16 -> Int16 -> Int16 # (*) :: Int16 -> Int16 -> Int16 # negate :: Int16 -> Int16 # abs :: Int16 -> Int16 # signum :: Int16 -> Int16 # fromInteger :: Integer -> Int16 #
Ord Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods compare :: Int16 -> Int16 -> Ordering # (<) :: Int16 -> Int16 -> Bool # (<=) :: Int16 -> Int16 -> Bool # (>) :: Int16 -> Int16 -> Bool # (>=) :: Int16 -> Int16 -> Bool # max :: Int16 -> Int16 -> Int16 # min :: Int16 -> Int16 -> Int16 #
Read Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods readsPrec :: Int -> ReadS Int16 # readList :: ReadS [Int16] # readPrec :: ReadPrec Int16 # readListPrec :: ReadPrec [Int16] #
Real Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods toRational :: Int16 -> Rational #
Show Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods showsPrec :: Int -> Int16 -> ShowS # show :: Int16 -> String # showList :: [Int16] -> ShowS #
Ix Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods range :: (Int16, Int16) -> [Int16] # index :: (Int16, Int16) -> Int16 -> Int # unsafeIndex :: (Int16, Int16) -> Int16 -> Int # inRange :: (Int16, Int16) -> Int16 -> Bool # rangeSize :: (Int16, Int16) -> Int # unsafeRangeSize :: (Int16, Int16) -> Int #
Bits Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods (.&.) :: Int16 -> Int16 -> Int16 # (.\|.) :: Int16 -> Int16 -> Int16 # xor :: Int16 -> Int16 -> Int16 # complement :: Int16 -> Int16 # shift :: Int16 -> Int -> Int16 # rotate :: Int16 -> Int -> Int16 # zeroBits :: Int16 # bit :: Int -> Int16 # setBit :: Int16 -> Int -> Int16 # clearBit :: Int16 -> Int -> Int16 # complementBit :: Int16 -> Int -> Int16 # testBit :: Int16 -> Int -> Bool # bitSizeMaybe :: Int16 -> Maybe Int # bitSize :: Int16 -> Int # isSigned :: Int16 -> Bool # shiftL :: Int16 -> Int -> Int16 # unsafeShiftL :: Int16 -> Int -> Int16 # shiftR :: Int16 -> Int -> Int16 # unsafeShiftR :: Int16 -> Int -> Int16 # rotateL :: Int16 -> Int -> Int16 # rotateR :: Int16 -> Int -> Int16 # popCount :: Int16 -> Int #
FiniteBits Int16	Since: base-4.6.0.0
Instance details Defined in GHC.Int Methods finiteBitSize :: Int16 -> Int # countLeadingZeros :: Int16 -> Int # countTrailingZeros :: Int16 -> Int #

data Int32 #

32-bit signed integer type

Instances

Instances details

Bounded Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods minBound :: Int32 # maxBound :: Int32 #
Enum Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods succ :: Int32 -> Int32 # pred :: Int32 -> Int32 # toEnum :: Int -> Int32 # fromEnum :: Int32 -> Int # enumFrom :: Int32 -> [Int32] # enumFromThen :: Int32 -> Int32 -> [Int32] # enumFromTo :: Int32 -> Int32 -> [Int32] # enumFromThenTo :: Int32 -> Int32 -> Int32 -> [Int32] #
Eq Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods (==) :: Int32 -> Int32 -> Bool # (/=) :: Int32 -> Int32 -> Bool #
Integral Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods quot :: Int32 -> Int32 -> Int32 # rem :: Int32 -> Int32 -> Int32 # div :: Int32 -> Int32 -> Int32 # mod :: Int32 -> Int32 -> Int32 # quotRem :: Int32 -> Int32 -> (Int32, Int32) # divMod :: Int32 -> Int32 -> (Int32, Int32) # toInteger :: Int32 -> Integer #
Num Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods (+) :: Int32 -> Int32 -> Int32 # (-) :: Int32 -> Int32 -> Int32 # (*) :: Int32 -> Int32 -> Int32 # negate :: Int32 -> Int32 # abs :: Int32 -> Int32 # signum :: Int32 -> Int32 # fromInteger :: Integer -> Int32 #
Ord Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods compare :: Int32 -> Int32 -> Ordering # (<) :: Int32 -> Int32 -> Bool # (<=) :: Int32 -> Int32 -> Bool # (>) :: Int32 -> Int32 -> Bool # (>=) :: Int32 -> Int32 -> Bool # max :: Int32 -> Int32 -> Int32 # min :: Int32 -> Int32 -> Int32 #
Read Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods readsPrec :: Int -> ReadS Int32 # readList :: ReadS [Int32] # readPrec :: ReadPrec Int32 # readListPrec :: ReadPrec [Int32] #
Real Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods toRational :: Int32 -> Rational #
Show Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods showsPrec :: Int -> Int32 -> ShowS # show :: Int32 -> String # showList :: [Int32] -> ShowS #
Ix Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods range :: (Int32, Int32) -> [Int32] # index :: (Int32, Int32) -> Int32 -> Int # unsafeIndex :: (Int32, Int32) -> Int32 -> Int # inRange :: (Int32, Int32) -> Int32 -> Bool # rangeSize :: (Int32, Int32) -> Int # unsafeRangeSize :: (Int32, Int32) -> Int #
Bits Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods (.&.) :: Int32 -> Int32 -> Int32 # (.\|.) :: Int32 -> Int32 -> Int32 # xor :: Int32 -> Int32 -> Int32 # complement :: Int32 -> Int32 # shift :: Int32 -> Int -> Int32 # rotate :: Int32 -> Int -> Int32 # zeroBits :: Int32 # bit :: Int -> Int32 # setBit :: Int32 -> Int -> Int32 # clearBit :: Int32 -> Int -> Int32 # complementBit :: Int32 -> Int -> Int32 # testBit :: Int32 -> Int -> Bool # bitSizeMaybe :: Int32 -> Maybe Int # bitSize :: Int32 -> Int # isSigned :: Int32 -> Bool # shiftL :: Int32 -> Int -> Int32 # unsafeShiftL :: Int32 -> Int -> Int32 # shiftR :: Int32 -> Int -> Int32 # unsafeShiftR :: Int32 -> Int -> Int32 # rotateL :: Int32 -> Int -> Int32 # rotateR :: Int32 -> Int -> Int32 # popCount :: Int32 -> Int #
FiniteBits Int32	Since: base-4.6.0.0
Instance details Defined in GHC.Int Methods finiteBitSize :: Int32 -> Int # countLeadingZeros :: Int32 -> Int # countTrailingZeros :: Int32 -> Int #

data Int64 #

64-bit signed integer type

Instances

Instances details

Bounded Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods minBound :: Int64 # maxBound :: Int64 #
Enum Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods succ :: Int64 -> Int64 # pred :: Int64 -> Int64 # toEnum :: Int -> Int64 # fromEnum :: Int64 -> Int # enumFrom :: Int64 -> [Int64] # enumFromThen :: Int64 -> Int64 -> [Int64] # enumFromTo :: Int64 -> Int64 -> [Int64] # enumFromThenTo :: Int64 -> Int64 -> Int64 -> [Int64] #
Eq Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods (==) :: Int64 -> Int64 -> Bool # (/=) :: Int64 -> Int64 -> Bool #
Integral Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods quot :: Int64 -> Int64 -> Int64 # rem :: Int64 -> Int64 -> Int64 # div :: Int64 -> Int64 -> Int64 # mod :: Int64 -> Int64 -> Int64 # quotRem :: Int64 -> Int64 -> (Int64, Int64) # divMod :: Int64 -> Int64 -> (Int64, Int64) # toInteger :: Int64 -> Integer #
Num Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods (+) :: Int64 -> Int64 -> Int64 # (-) :: Int64 -> Int64 -> Int64 # (*) :: Int64 -> Int64 -> Int64 # negate :: Int64 -> Int64 # abs :: Int64 -> Int64 # signum :: Int64 -> Int64 # fromInteger :: Integer -> Int64 #
Ord Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods compare :: Int64 -> Int64 -> Ordering # (<) :: Int64 -> Int64 -> Bool # (<=) :: Int64 -> Int64 -> Bool # (>) :: Int64 -> Int64 -> Bool # (>=) :: Int64 -> Int64 -> Bool # max :: Int64 -> Int64 -> Int64 # min :: Int64 -> Int64 -> Int64 #
Read Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods readsPrec :: Int -> ReadS Int64 # readList :: ReadS [Int64] # readPrec :: ReadPrec Int64 # readListPrec :: ReadPrec [Int64] #
Real Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods toRational :: Int64 -> Rational #
Show Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods showsPrec :: Int -> Int64 -> ShowS # show :: Int64 -> String # showList :: [Int64] -> ShowS #
Ix Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods range :: (Int64, Int64) -> [Int64] # index :: (Int64, Int64) -> Int64 -> Int # unsafeIndex :: (Int64, Int64) -> Int64 -> Int # inRange :: (Int64, Int64) -> Int64 -> Bool # rangeSize :: (Int64, Int64) -> Int # unsafeRangeSize :: (Int64, Int64) -> Int #
Bits Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods (.&.) :: Int64 -> Int64 -> Int64 # (.\|.) :: Int64 -> Int64 -> Int64 # xor :: Int64 -> Int64 -> Int64 # complement :: Int64 -> Int64 # shift :: Int64 -> Int -> Int64 # rotate :: Int64 -> Int -> Int64 # zeroBits :: Int64 # bit :: Int -> Int64 # setBit :: Int64 -> Int -> Int64 # clearBit :: Int64 -> Int -> Int64 # complementBit :: Int64 -> Int -> Int64 # testBit :: Int64 -> Int -> Bool # bitSizeMaybe :: Int64 -> Maybe Int # bitSize :: Int64 -> Int # isSigned :: Int64 -> Bool # shiftL :: Int64 -> Int -> Int64 # unsafeShiftL :: Int64 -> Int -> Int64 # shiftR :: Int64 -> Int -> Int64 # unsafeShiftR :: Int64 -> Int -> Int64 # rotateL :: Int64 -> Int -> Int64 # rotateR :: Int64 -> Int -> Int64 # popCount :: Int64 -> Int #
FiniteBits Int64	Since: base-4.6.0.0
Instance details Defined in GHC.Int Methods finiteBitSize :: Int64 -> Int # countLeadingZeros :: Int64 -> Int # countTrailingZeros :: Int64 -> Int #

data Int8 #

8-bit signed integer type

Instances

Instances details

Bounded Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods minBound :: Int8 # maxBound :: Int8 #
Enum Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods succ :: Int8 -> Int8 # pred :: Int8 -> Int8 # toEnum :: Int -> Int8 # fromEnum :: Int8 -> Int # enumFrom :: Int8 -> [Int8] # enumFromThen :: Int8 -> Int8 -> [Int8] # enumFromTo :: Int8 -> Int8 -> [Int8] # enumFromThenTo :: Int8 -> Int8 -> Int8 -> [Int8] #
Eq Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods (==) :: Int8 -> Int8 -> Bool # (/=) :: Int8 -> Int8 -> Bool #
Integral Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods quot :: Int8 -> Int8 -> Int8 # rem :: Int8 -> Int8 -> Int8 # div :: Int8 -> Int8 -> Int8 # mod :: Int8 -> Int8 -> Int8 # quotRem :: Int8 -> Int8 -> (Int8, Int8) # divMod :: Int8 -> Int8 -> (Int8, Int8) # toInteger :: Int8 -> Integer #
Num Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods (+) :: Int8 -> Int8 -> Int8 # (-) :: Int8 -> Int8 -> Int8 # (*) :: Int8 -> Int8 -> Int8 # negate :: Int8 -> Int8 # abs :: Int8 -> Int8 # signum :: Int8 -> Int8 # fromInteger :: Integer -> Int8 #
Ord Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods compare :: Int8 -> Int8 -> Ordering # (<) :: Int8 -> Int8 -> Bool # (<=) :: Int8 -> Int8 -> Bool # (>) :: Int8 -> Int8 -> Bool # (>=) :: Int8 -> Int8 -> Bool # max :: Int8 -> Int8 -> Int8 # min :: Int8 -> Int8 -> Int8 #
Read Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods readsPrec :: Int -> ReadS Int8 # readList :: ReadS [Int8] # readPrec :: ReadPrec Int8 # readListPrec :: ReadPrec [Int8] #
Real Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods toRational :: Int8 -> Rational #
Show Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods showsPrec :: Int -> Int8 -> ShowS # show :: Int8 -> String # showList :: [Int8] -> ShowS #
Ix Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods range :: (Int8, Int8) -> [Int8] # index :: (Int8, Int8) -> Int8 -> Int # unsafeIndex :: (Int8, Int8) -> Int8 -> Int # inRange :: (Int8, Int8) -> Int8 -> Bool # rangeSize :: (Int8, Int8) -> Int # unsafeRangeSize :: (Int8, Int8) -> Int #
Bits Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods (.&.) :: Int8 -> Int8 -> Int8 # (.\|.) :: Int8 -> Int8 -> Int8 # xor :: Int8 -> Int8 -> Int8 # complement :: Int8 -> Int8 # shift :: Int8 -> Int -> Int8 # rotate :: Int8 -> Int -> Int8 # zeroBits :: Int8 # bit :: Int -> Int8 # setBit :: Int8 -> Int -> Int8 # clearBit :: Int8 -> Int -> Int8 # complementBit :: Int8 -> Int -> Int8 # testBit :: Int8 -> Int -> Bool # bitSizeMaybe :: Int8 -> Maybe Int # bitSize :: Int8 -> Int # isSigned :: Int8 -> Bool # shiftL :: Int8 -> Int -> Int8 # unsafeShiftL :: Int8 -> Int -> Int8 # shiftR :: Int8 -> Int -> Int8 # unsafeShiftR :: Int8 -> Int -> Int8 # rotateL :: Int8 -> Int -> Int8 # rotateR :: Int8 -> Int -> Int8 # popCount :: Int8 -> Int #
FiniteBits Int8	Since: base-4.6.0.0
Instance details Defined in GHC.Int Methods finiteBitSize :: Int8 -> Int # countLeadingZeros :: Int8 -> Int # countTrailingZeros :: Int8 -> Int #

data Word #

A Word is an unsigned integral type, with the same size as Int.

Instances

Instances details

Bounded Word	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Word # maxBound :: Word #
Enum Word	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Word -> Word # pred :: Word -> Word # toEnum :: Int -> Word # fromEnum :: Word -> Int # enumFrom :: Word -> [Word] # enumFromThen :: Word -> Word -> [Word] # enumFromTo :: Word -> Word -> [Word] # enumFromThenTo :: Word -> Word -> Word -> [Word] #
Eq Word
Instance details Defined in GHC.Classes Methods (==) :: Word -> Word -> Bool # (/=) :: Word -> Word -> Bool #
Integral Word	Since: base-2.1
Instance details Defined in GHC.Real Methods quot :: Word -> Word -> Word # rem :: Word -> Word -> Word # div :: Word -> Word -> Word # mod :: Word -> Word -> Word # quotRem :: Word -> Word -> (Word, Word) # divMod :: Word -> Word -> (Word, Word) # toInteger :: Word -> Integer #
Num Word	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Word -> Word -> Word # (-) :: Word -> Word -> Word # (*) :: Word -> Word -> Word # negate :: Word -> Word # abs :: Word -> Word # signum :: Word -> Word # fromInteger :: Integer -> Word #
Ord Word
Instance details Defined in GHC.Classes Methods compare :: Word -> Word -> Ordering # (<) :: Word -> Word -> Bool # (<=) :: Word -> Word -> Bool # (>) :: Word -> Word -> Bool # (>=) :: Word -> Word -> Bool # max :: Word -> Word -> Word # min :: Word -> Word -> Word #
Read Word	Since: base-4.5.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word # readList :: ReadS [Word] # readPrec :: ReadPrec Word # readListPrec :: ReadPrec [Word] #
Real Word	Since: base-2.1
Instance details Defined in GHC.Real Methods toRational :: Word -> Rational #
Show Word	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Word -> ShowS # show :: Word -> String # showList :: [Word] -> ShowS #
Bits Word	Since: base-2.1
Instance details Defined in Data.Bits Methods (.&.) :: Word -> Word -> Word # (.\|.) :: Word -> Word -> Word # xor :: Word -> Word -> Word # complement :: Word -> Word # shift :: Word -> Int -> Word # rotate :: Word -> Int -> Word # zeroBits :: Word # bit :: Int -> Word # setBit :: Word -> Int -> Word # clearBit :: Word -> Int -> Word # complementBit :: Word -> Int -> Word # testBit :: Word -> Int -> Bool # bitSizeMaybe :: Word -> Maybe Int # bitSize :: Word -> Int # isSigned :: Word -> Bool # shiftL :: Word -> Int -> Word # unsafeShiftL :: Word -> Int -> Word # shiftR :: Word -> Int -> Word # unsafeShiftR :: Word -> Int -> Word # rotateL :: Word -> Int -> Word # rotateR :: Word -> Int -> Word # popCount :: Word -> Int #
FiniteBits Word	Since: base-4.6.0.0
Instance details Defined in Data.Bits Methods finiteBitSize :: Word -> Int # countLeadingZeros :: Word -> Int # countTrailingZeros :: Word -> Int #
Generic1 (URec Word :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Word) :: k -> Type # Methods from1 :: forall (a :: k0). URec Word a -> Rep1 (URec Word) a # to1 :: forall (a :: k0). Rep1 (URec Word) a -> URec Word a #
Foldable (UWord :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UWord m -> m # foldMap :: Monoid m => (a -> m) -> UWord a -> m # foldMap' :: Monoid m => (a -> m) -> UWord a -> m # foldr :: (a -> b -> b) -> b -> UWord a -> b # foldr' :: (a -> b -> b) -> b -> UWord a -> b # foldl :: (b -> a -> b) -> b -> UWord a -> b # foldl' :: (b -> a -> b) -> b -> UWord a -> b # foldr1 :: (a -> a -> a) -> UWord a -> a # foldl1 :: (a -> a -> a) -> UWord a -> a # toList :: UWord a -> [a] # null :: UWord a -> Bool # length :: UWord a -> Int # elem :: Eq a => a -> UWord a -> Bool # maximum :: Ord a => UWord a -> a # minimum :: Ord a => UWord a -> a # sum :: Num a => UWord a -> a # product :: Num a => UWord a -> a #
Traversable (UWord :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UWord a -> f (UWord b) # sequenceA :: Applicative f => UWord (f a) -> f (UWord a) # mapM :: Monad m => (a -> m b) -> UWord a -> m (UWord b) # sequence :: Monad m => UWord (m a) -> m (UWord a) #
Functor (URec Word :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods fmap :: (a -> b) -> URec Word a -> URec Word b # (<$) :: a -> URec Word b -> URec Word a #
Eq (URec Word p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: URec Word p -> URec Word p -> Bool # (/=) :: URec Word p -> URec Word p -> Bool #
Ord (URec Word p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: URec Word p -> URec Word p -> Ordering # (<) :: URec Word p -> URec Word p -> Bool # (<=) :: URec Word p -> URec Word p -> Bool # (>) :: URec Word p -> URec Word p -> Bool # (>=) :: URec Word p -> URec Word p -> Bool # max :: URec Word p -> URec Word p -> URec Word p # min :: URec Word p -> URec Word p -> URec Word p #
Show (URec Word p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Word p -> ShowS # show :: URec Word p -> String # showList :: [URec Word p] -> ShowS #
Generic (URec Word p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (URec Word p) :: Type -> Type # Methods from :: URec Word p -> Rep (URec Word p) x # to :: Rep (URec Word p) x -> URec Word p #
data URec Word (p :: k)	Used for marking occurrences of `Word#` Since: base-4.9.0.0
Instance details Defined in GHC.Generics data URec Word (p :: k) = UWord { uWord# :: Word# }
type Rep1 (URec Word :: k -> Type)
Instance details Defined in GHC.Generics type Rep1 (URec Word :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UWord" 'PrefixI 'True) (S1 ('MetaSel ('Just "uWord#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UWord :: k -> Type)))
type Rep (URec Word p)
Instance details Defined in GHC.Generics type Rep (URec Word p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UWord" 'PrefixI 'True) (S1 ('MetaSel ('Just "uWord#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UWord :: Type -> Type)))

data Word16 #

16-bit unsigned integer type

Instances

Instances details

Bounded Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods minBound :: Word16 # maxBound :: Word16 #
Enum Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods succ :: Word16 -> Word16 # pred :: Word16 -> Word16 # toEnum :: Int -> Word16 # fromEnum :: Word16 -> Int # enumFrom :: Word16 -> [Word16] # enumFromThen :: Word16 -> Word16 -> [Word16] # enumFromTo :: Word16 -> Word16 -> [Word16] # enumFromThenTo :: Word16 -> Word16 -> Word16 -> [Word16] #
Eq Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods (==) :: Word16 -> Word16 -> Bool # (/=) :: Word16 -> Word16 -> Bool #
Integral Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods quot :: Word16 -> Word16 -> Word16 # rem :: Word16 -> Word16 -> Word16 # div :: Word16 -> Word16 -> Word16 # mod :: Word16 -> Word16 -> Word16 # quotRem :: Word16 -> Word16 -> (Word16, Word16) # divMod :: Word16 -> Word16 -> (Word16, Word16) # toInteger :: Word16 -> Integer #
Num Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods (+) :: Word16 -> Word16 -> Word16 # (-) :: Word16 -> Word16 -> Word16 # (*) :: Word16 -> Word16 -> Word16 # negate :: Word16 -> Word16 # abs :: Word16 -> Word16 # signum :: Word16 -> Word16 # fromInteger :: Integer -> Word16 #
Ord Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods compare :: Word16 -> Word16 -> Ordering # (<) :: Word16 -> Word16 -> Bool # (<=) :: Word16 -> Word16 -> Bool # (>) :: Word16 -> Word16 -> Bool # (>=) :: Word16 -> Word16 -> Bool # max :: Word16 -> Word16 -> Word16 # min :: Word16 -> Word16 -> Word16 #
Read Word16	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word16 # readList :: ReadS [Word16] # readPrec :: ReadPrec Word16 # readListPrec :: ReadPrec [Word16] #
Real Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods toRational :: Word16 -> Rational #
Show Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods showsPrec :: Int -> Word16 -> ShowS # show :: Word16 -> String # showList :: [Word16] -> ShowS #
Ix Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods range :: (Word16, Word16) -> [Word16] # index :: (Word16, Word16) -> Word16 -> Int # unsafeIndex :: (Word16, Word16) -> Word16 -> Int # inRange :: (Word16, Word16) -> Word16 -> Bool # rangeSize :: (Word16, Word16) -> Int # unsafeRangeSize :: (Word16, Word16) -> Int #
Bits Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods (.&.) :: Word16 -> Word16 -> Word16 # (.\|.) :: Word16 -> Word16 -> Word16 # xor :: Word16 -> Word16 -> Word16 # complement :: Word16 -> Word16 # shift :: Word16 -> Int -> Word16 # rotate :: Word16 -> Int -> Word16 # zeroBits :: Word16 # bit :: Int -> Word16 # setBit :: Word16 -> Int -> Word16 # clearBit :: Word16 -> Int -> Word16 # complementBit :: Word16 -> Int -> Word16 # testBit :: Word16 -> Int -> Bool # bitSizeMaybe :: Word16 -> Maybe Int # bitSize :: Word16 -> Int # isSigned :: Word16 -> Bool # shiftL :: Word16 -> Int -> Word16 # unsafeShiftL :: Word16 -> Int -> Word16 # shiftR :: Word16 -> Int -> Word16 # unsafeShiftR :: Word16 -> Int -> Word16 # rotateL :: Word16 -> Int -> Word16 # rotateR :: Word16 -> Int -> Word16 # popCount :: Word16 -> Int #
FiniteBits Word16	Since: base-4.6.0.0
Instance details Defined in GHC.Word Methods finiteBitSize :: Word16 -> Int # countLeadingZeros :: Word16 -> Int # countTrailingZeros :: Word16 -> Int #

data Word32 #

32-bit unsigned integer type

Instances

Instances details

Bounded Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods minBound :: Word32 # maxBound :: Word32 #
Enum Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods succ :: Word32 -> Word32 # pred :: Word32 -> Word32 # toEnum :: Int -> Word32 # fromEnum :: Word32 -> Int # enumFrom :: Word32 -> [Word32] # enumFromThen :: Word32 -> Word32 -> [Word32] # enumFromTo :: Word32 -> Word32 -> [Word32] # enumFromThenTo :: Word32 -> Word32 -> Word32 -> [Word32] #
Eq Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods (==) :: Word32 -> Word32 -> Bool # (/=) :: Word32 -> Word32 -> Bool #
Integral Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods quot :: Word32 -> Word32 -> Word32 # rem :: Word32 -> Word32 -> Word32 # div :: Word32 -> Word32 -> Word32 # mod :: Word32 -> Word32 -> Word32 # quotRem :: Word32 -> Word32 -> (Word32, Word32) # divMod :: Word32 -> Word32 -> (Word32, Word32) # toInteger :: Word32 -> Integer #
Num Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods (+) :: Word32 -> Word32 -> Word32 # (-) :: Word32 -> Word32 -> Word32 # (*) :: Word32 -> Word32 -> Word32 # negate :: Word32 -> Word32 # abs :: Word32 -> Word32 # signum :: Word32 -> Word32 # fromInteger :: Integer -> Word32 #
Ord Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods compare :: Word32 -> Word32 -> Ordering # (<) :: Word32 -> Word32 -> Bool # (<=) :: Word32 -> Word32 -> Bool # (>) :: Word32 -> Word32 -> Bool # (>=) :: Word32 -> Word32 -> Bool # max :: Word32 -> Word32 -> Word32 # min :: Word32 -> Word32 -> Word32 #
Read Word32	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word32 # readList :: ReadS [Word32] # readPrec :: ReadPrec Word32 # readListPrec :: ReadPrec [Word32] #
Real Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods toRational :: Word32 -> Rational #
Show Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods showsPrec :: Int -> Word32 -> ShowS # show :: Word32 -> String # showList :: [Word32] -> ShowS #
Ix Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods range :: (Word32, Word32) -> [Word32] # index :: (Word32, Word32) -> Word32 -> Int # unsafeIndex :: (Word32, Word32) -> Word32 -> Int # inRange :: (Word32, Word32) -> Word32 -> Bool # rangeSize :: (Word32, Word32) -> Int # unsafeRangeSize :: (Word32, Word32) -> Int #
Bits Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods (.&.) :: Word32 -> Word32 -> Word32 # (.\|.) :: Word32 -> Word32 -> Word32 # xor :: Word32 -> Word32 -> Word32 # complement :: Word32 -> Word32 # shift :: Word32 -> Int -> Word32 # rotate :: Word32 -> Int -> Word32 # zeroBits :: Word32 # bit :: Int -> Word32 # setBit :: Word32 -> Int -> Word32 # clearBit :: Word32 -> Int -> Word32 # complementBit :: Word32 -> Int -> Word32 # testBit :: Word32 -> Int -> Bool # bitSizeMaybe :: Word32 -> Maybe Int # bitSize :: Word32 -> Int # isSigned :: Word32 -> Bool # shiftL :: Word32 -> Int -> Word32 # unsafeShiftL :: Word32 -> Int -> Word32 # shiftR :: Word32 -> Int -> Word32 # unsafeShiftR :: Word32 -> Int -> Word32 # rotateL :: Word32 -> Int -> Word32 # rotateR :: Word32 -> Int -> Word32 # popCount :: Word32 -> Int #
FiniteBits Word32	Since: base-4.6.0.0
Instance details Defined in GHC.Word Methods finiteBitSize :: Word32 -> Int # countLeadingZeros :: Word32 -> Int # countTrailingZeros :: Word32 -> Int #

data Word64 #

64-bit unsigned integer type

Instances

Instances details

Bounded Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods minBound :: Word64 # maxBound :: Word64 #
Enum Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods succ :: Word64 -> Word64 # pred :: Word64 -> Word64 # toEnum :: Int -> Word64 # fromEnum :: Word64 -> Int # enumFrom :: Word64 -> [Word64] # enumFromThen :: Word64 -> Word64 -> [Word64] # enumFromTo :: Word64 -> Word64 -> [Word64] # enumFromThenTo :: Word64 -> Word64 -> Word64 -> [Word64] #
Eq Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods (==) :: Word64 -> Word64 -> Bool # (/=) :: Word64 -> Word64 -> Bool #
Integral Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods quot :: Word64 -> Word64 -> Word64 # rem :: Word64 -> Word64 -> Word64 # div :: Word64 -> Word64 -> Word64 # mod :: Word64 -> Word64 -> Word64 # quotRem :: Word64 -> Word64 -> (Word64, Word64) # divMod :: Word64 -> Word64 -> (Word64, Word64) # toInteger :: Word64 -> Integer #
Num Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods (+) :: Word64 -> Word64 -> Word64 # (-) :: Word64 -> Word64 -> Word64 # (*) :: Word64 -> Word64 -> Word64 # negate :: Word64 -> Word64 # abs :: Word64 -> Word64 # signum :: Word64 -> Word64 # fromInteger :: Integer -> Word64 #
Ord Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods compare :: Word64 -> Word64 -> Ordering # (<) :: Word64 -> Word64 -> Bool # (<=) :: Word64 -> Word64 -> Bool # (>) :: Word64 -> Word64 -> Bool # (>=) :: Word64 -> Word64 -> Bool # max :: Word64 -> Word64 -> Word64 # min :: Word64 -> Word64 -> Word64 #
Read Word64	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word64 # readList :: ReadS [Word64] # readPrec :: ReadPrec Word64 # readListPrec :: ReadPrec [Word64] #
Real Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods toRational :: Word64 -> Rational #
Show Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods showsPrec :: Int -> Word64 -> ShowS # show :: Word64 -> String # showList :: [Word64] -> ShowS #
Ix Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods range :: (Word64, Word64) -> [Word64] # index :: (Word64, Word64) -> Word64 -> Int # unsafeIndex :: (Word64, Word64) -> Word64 -> Int # inRange :: (Word64, Word64) -> Word64 -> Bool # rangeSize :: (Word64, Word64) -> Int # unsafeRangeSize :: (Word64, Word64) -> Int #
Bits Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods (.&.) :: Word64 -> Word64 -> Word64 # (.\|.) :: Word64 -> Word64 -> Word64 # xor :: Word64 -> Word64 -> Word64 # complement :: Word64 -> Word64 # shift :: Word64 -> Int -> Word64 # rotate :: Word64 -> Int -> Word64 # zeroBits :: Word64 # bit :: Int -> Word64 # setBit :: Word64 -> Int -> Word64 # clearBit :: Word64 -> Int -> Word64 # complementBit :: Word64 -> Int -> Word64 # testBit :: Word64 -> Int -> Bool # bitSizeMaybe :: Word64 -> Maybe Int # bitSize :: Word64 -> Int # isSigned :: Word64 -> Bool # shiftL :: Word64 -> Int -> Word64 # unsafeShiftL :: Word64 -> Int -> Word64 # shiftR :: Word64 -> Int -> Word64 # unsafeShiftR :: Word64 -> Int -> Word64 # rotateL :: Word64 -> Int -> Word64 # rotateR :: Word64 -> Int -> Word64 # popCount :: Word64 -> Int #
FiniteBits Word64	Since: base-4.6.0.0
Instance details Defined in GHC.Word Methods finiteBitSize :: Word64 -> Int # countLeadingZeros :: Word64 -> Int # countTrailingZeros :: Word64 -> Int #

data Word8 #

8-bit unsigned integer type

Instances

Instances details

Bounded Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods minBound :: Word8 # maxBound :: Word8 #
Enum Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods succ :: Word8 -> Word8 # pred :: Word8 -> Word8 # toEnum :: Int -> Word8 # fromEnum :: Word8 -> Int # enumFrom :: Word8 -> [Word8] # enumFromThen :: Word8 -> Word8 -> [Word8] # enumFromTo :: Word8 -> Word8 -> [Word8] # enumFromThenTo :: Word8 -> Word8 -> Word8 -> [Word8] #
Eq Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods (==) :: Word8 -> Word8 -> Bool # (/=) :: Word8 -> Word8 -> Bool #
Integral Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods quot :: Word8 -> Word8 -> Word8 # rem :: Word8 -> Word8 -> Word8 # div :: Word8 -> Word8 -> Word8 # mod :: Word8 -> Word8 -> Word8 # quotRem :: Word8 -> Word8 -> (Word8, Word8) # divMod :: Word8 -> Word8 -> (Word8, Word8) # toInteger :: Word8 -> Integer #
Num Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods (+) :: Word8 -> Word8 -> Word8 # (-) :: Word8 -> Word8 -> Word8 # (*) :: Word8 -> Word8 -> Word8 # negate :: Word8 -> Word8 # abs :: Word8 -> Word8 # signum :: Word8 -> Word8 # fromInteger :: Integer -> Word8 #
Ord Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods compare :: Word8 -> Word8 -> Ordering # (<) :: Word8 -> Word8 -> Bool # (<=) :: Word8 -> Word8 -> Bool # (>) :: Word8 -> Word8 -> Bool # (>=) :: Word8 -> Word8 -> Bool # max :: Word8 -> Word8 -> Word8 # min :: Word8 -> Word8 -> Word8 #
Read Word8	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word8 # readList :: ReadS [Word8] # readPrec :: ReadPrec Word8 # readListPrec :: ReadPrec [Word8] #
Real Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods toRational :: Word8 -> Rational #
Show Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods showsPrec :: Int -> Word8 -> ShowS # show :: Word8 -> String # showList :: [Word8] -> ShowS #
Ix Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods range :: (Word8, Word8) -> [Word8] # index :: (Word8, Word8) -> Word8 -> Int # unsafeIndex :: (Word8, Word8) -> Word8 -> Int # inRange :: (Word8, Word8) -> Word8 -> Bool # rangeSize :: (Word8, Word8) -> Int # unsafeRangeSize :: (Word8, Word8) -> Int #
Bits Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods (.&.) :: Word8 -> Word8 -> Word8 # (.\|.) :: Word8 -> Word8 -> Word8 # xor :: Word8 -> Word8 -> Word8 # complement :: Word8 -> Word8 # shift :: Word8 -> Int -> Word8 # rotate :: Word8 -> Int -> Word8 # zeroBits :: Word8 # bit :: Int -> Word8 # setBit :: Word8 -> Int -> Word8 # clearBit :: Word8 -> Int -> Word8 # complementBit :: Word8 -> Int -> Word8 # testBit :: Word8 -> Int -> Bool # bitSizeMaybe :: Word8 -> Maybe Int # bitSize :: Word8 -> Int # isSigned :: Word8 -> Bool # shiftL :: Word8 -> Int -> Word8 # unsafeShiftL :: Word8 -> Int -> Word8 # shiftR :: Word8 -> Int -> Word8 # unsafeShiftR :: Word8 -> Int -> Word8 # rotateL :: Word8 -> Int -> Word8 # rotateR :: Word8 -> Int -> Word8 # popCount :: Word8 -> Int #
FiniteBits Word8	Since: base-4.6.0.0
Instance details Defined in GHC.Word Methods finiteBitSize :: Word8 -> Int # countLeadingZeros :: Word8 -> Int # countTrailingZeros :: Word8 -> Int #

Floating point

data Float #

Single-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE single-precision type.

Instances

Instances details

Eq Float	Note that due to the presence of `NaN`, `Float`'s `Eq` instance does not satisfy reflexivity. `>>>` `0/0 == (0/0 :: Float)`False Also note that `Float`'s `Eq` instance does not satisfy substitutivity: `>>>` `0 == (-0 :: Float)`True `>>>` `recip 0 == recip (-0 :: Float)`False
Instance details Defined in GHC.Classes Methods (==) :: Float -> Float -> Bool # (/=) :: Float -> Float -> Bool #
Floating Float	Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Float # exp :: Float -> Float # log :: Float -> Float # sqrt :: Float -> Float # (**) :: Float -> Float -> Float # logBase :: Float -> Float -> Float # sin :: Float -> Float # cos :: Float -> Float # tan :: Float -> Float # asin :: Float -> Float # acos :: Float -> Float # atan :: Float -> Float # sinh :: Float -> Float # cosh :: Float -> Float # tanh :: Float -> Float # asinh :: Float -> Float # acosh :: Float -> Float # atanh :: Float -> Float # log1p :: Float -> Float # expm1 :: Float -> Float # log1pexp :: Float -> Float # log1mexp :: Float -> Float #
Ord Float	Note that due to the presence of `NaN`, `Float`'s `Ord` instance does not satisfy reflexivity. `>>>` `0/0 <= (0/0 :: Float)`False Also note that, due to the same, `Ord`'s operator interactions are not respected by `Float`'s instance: `>>>` `(0/0 :: Float) > 1`False `>>>` `compare (0/0 :: Float) 1`GT
Instance details Defined in GHC.Classes Methods compare :: Float -> Float -> Ordering # (<) :: Float -> Float -> Bool # (<=) :: Float -> Float -> Bool # (>) :: Float -> Float -> Bool # (>=) :: Float -> Float -> Bool # max :: Float -> Float -> Float # min :: Float -> Float -> Float #
Read Float	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Float # readList :: ReadS [Float] # readPrec :: ReadPrec Float # readListPrec :: ReadPrec [Float] #
RealFloat Float	Since: base-2.1
Instance details Defined in GHC.Float Methods floatRadix :: Float -> Integer # floatDigits :: Float -> Int # floatRange :: Float -> (Int, Int) # decodeFloat :: Float -> (Integer, Int) # encodeFloat :: Integer -> Int -> Float # exponent :: Float -> Int # significand :: Float -> Float # scaleFloat :: Int -> Float -> Float # isNaN :: Float -> Bool # isInfinite :: Float -> Bool # isDenormalized :: Float -> Bool # isNegativeZero :: Float -> Bool # isIEEE :: Float -> Bool # atan2 :: Float -> Float -> Float #
Generic1 (URec Float :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Float) :: k -> Type # Methods from1 :: forall (a :: k0). URec Float a -> Rep1 (URec Float) a # to1 :: forall (a :: k0). Rep1 (URec Float) a -> URec Float a #
Foldable (UFloat :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UFloat m -> m # foldMap :: Monoid m => (a -> m) -> UFloat a -> m # foldMap' :: Monoid m => (a -> m) -> UFloat a -> m # foldr :: (a -> b -> b) -> b -> UFloat a -> b # foldr' :: (a -> b -> b) -> b -> UFloat a -> b # foldl :: (b -> a -> b) -> b -> UFloat a -> b # foldl' :: (b -> a -> b) -> b -> UFloat a -> b # foldr1 :: (a -> a -> a) -> UFloat a -> a # foldl1 :: (a -> a -> a) -> UFloat a -> a # toList :: UFloat a -> [a] # null :: UFloat a -> Bool # length :: UFloat a -> Int # elem :: Eq a => a -> UFloat a -> Bool # maximum :: Ord a => UFloat a -> a # minimum :: Ord a => UFloat a -> a # sum :: Num a => UFloat a -> a # product :: Num a => UFloat a -> a #
Traversable (UFloat :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UFloat a -> f (UFloat b) # sequenceA :: Applicative f => UFloat (f a) -> f (UFloat a) # mapM :: Monad m => (a -> m b) -> UFloat a -> m (UFloat b) # sequence :: Monad m => UFloat (m a) -> m (UFloat a) #
Functor (URec Float :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods fmap :: (a -> b) -> URec Float a -> URec Float b # (<$) :: a -> URec Float b -> URec Float a #
Eq (URec Float p)
Instance details Defined in GHC.Generics Methods (==) :: URec Float p -> URec Float p -> Bool # (/=) :: URec Float p -> URec Float p -> Bool #
Ord (URec Float p)
Instance details Defined in GHC.Generics Methods compare :: URec Float p -> URec Float p -> Ordering # (<) :: URec Float p -> URec Float p -> Bool # (<=) :: URec Float p -> URec Float p -> Bool # (>) :: URec Float p -> URec Float p -> Bool # (>=) :: URec Float p -> URec Float p -> Bool # max :: URec Float p -> URec Float p -> URec Float p # min :: URec Float p -> URec Float p -> URec Float p #
Show (URec Float p)
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Float p -> ShowS # show :: URec Float p -> String # showList :: [URec Float p] -> ShowS #
Generic (URec Float p)
Instance details Defined in GHC.Generics Associated Types type Rep (URec Float p) :: Type -> Type # Methods from :: URec Float p -> Rep (URec Float p) x # to :: Rep (URec Float p) x -> URec Float p #
data URec Float (p :: k)	Used for marking occurrences of `Float#` Since: base-4.9.0.0
Instance details Defined in GHC.Generics data URec Float (p :: k) = UFloat { uFloat# :: Float# }
type Rep1 (URec Float :: k -> Type)
Instance details Defined in GHC.Generics type Rep1 (URec Float :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UFloat" 'PrefixI 'True) (S1 ('MetaSel ('Just "uFloat#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UFloat :: k -> Type)))
type Rep (URec Float p)
Instance details Defined in GHC.Generics type Rep (URec Float p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UFloat" 'PrefixI 'True) (S1 ('MetaSel ('Just "uFloat#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UFloat :: Type -> Type)))

data Double #

Double-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE double-precision type.

Instances

Instances details

Eq Double	Note that due to the presence of `NaN`, `Double`'s `Eq` instance does not satisfy reflexivity. `>>>` `0/0 == (0/0 :: Double)`False Also note that `Double`'s `Eq` instance does not satisfy substitutivity: `>>>` `0 == (-0 :: Double)`True `>>>` `recip 0 == recip (-0 :: Double)`False
Instance details Defined in GHC.Classes Methods (==) :: Double -> Double -> Bool # (/=) :: Double -> Double -> Bool #
Floating Double	Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Double # exp :: Double -> Double # log :: Double -> Double # sqrt :: Double -> Double # (**) :: Double -> Double -> Double # logBase :: Double -> Double -> Double # sin :: Double -> Double # cos :: Double -> Double # tan :: Double -> Double # asin :: Double -> Double # acos :: Double -> Double # atan :: Double -> Double # sinh :: Double -> Double # cosh :: Double -> Double # tanh :: Double -> Double # asinh :: Double -> Double # acosh :: Double -> Double # atanh :: Double -> Double # log1p :: Double -> Double # expm1 :: Double -> Double # log1pexp :: Double -> Double # log1mexp :: Double -> Double #
Ord Double	Note that due to the presence of `NaN`, `Double`'s `Ord` instance does not satisfy reflexivity. `>>>` `0/0 <= (0/0 :: Double)`False Also note that, due to the same, `Ord`'s operator interactions are not respected by `Double`'s instance: `>>>` `(0/0 :: Double) > 1`False `>>>` `compare (0/0 :: Double) 1`GT
Instance details Defined in GHC.Classes Methods compare :: Double -> Double -> Ordering # (<) :: Double -> Double -> Bool # (<=) :: Double -> Double -> Bool # (>) :: Double -> Double -> Bool # (>=) :: Double -> Double -> Bool # max :: Double -> Double -> Double # min :: Double -> Double -> Double #
Read Double	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Double # readList :: ReadS [Double] # readPrec :: ReadPrec Double # readListPrec :: ReadPrec [Double] #
RealFloat Double	Since: base-2.1
Instance details Defined in GHC.Float Methods floatRadix :: Double -> Integer # floatDigits :: Double -> Int # floatRange :: Double -> (Int, Int) # decodeFloat :: Double -> (Integer, Int) # encodeFloat :: Integer -> Int -> Double # exponent :: Double -> Int # significand :: Double -> Double # scaleFloat :: Int -> Double -> Double # isNaN :: Double -> Bool # isInfinite :: Double -> Bool # isDenormalized :: Double -> Bool # isNegativeZero :: Double -> Bool # isIEEE :: Double -> Bool # atan2 :: Double -> Double -> Double #
Generic1 (URec Double :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Double) :: k -> Type # Methods from1 :: forall (a :: k0). URec Double a -> Rep1 (URec Double) a # to1 :: forall (a :: k0). Rep1 (URec Double) a -> URec Double a #
Foldable (UDouble :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UDouble m -> m # foldMap :: Monoid m => (a -> m) -> UDouble a -> m # foldMap' :: Monoid m => (a -> m) -> UDouble a -> m # foldr :: (a -> b -> b) -> b -> UDouble a -> b # foldr' :: (a -> b -> b) -> b -> UDouble a -> b # foldl :: (b -> a -> b) -> b -> UDouble a -> b # foldl' :: (b -> a -> b) -> b -> UDouble a -> b # foldr1 :: (a -> a -> a) -> UDouble a -> a # foldl1 :: (a -> a -> a) -> UDouble a -> a # toList :: UDouble a -> [a] # null :: UDouble a -> Bool # length :: UDouble a -> Int # elem :: Eq a => a -> UDouble a -> Bool # maximum :: Ord a => UDouble a -> a # minimum :: Ord a => UDouble a -> a # sum :: Num a => UDouble a -> a # product :: Num a => UDouble a -> a #
Traversable (UDouble :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UDouble a -> f (UDouble b) # sequenceA :: Applicative f => UDouble (f a) -> f (UDouble a) # mapM :: Monad m => (a -> m b) -> UDouble a -> m (UDouble b) # sequence :: Monad m => UDouble (m a) -> m (UDouble a) #
Functor (URec Double :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods fmap :: (a -> b) -> URec Double a -> URec Double b # (<$) :: a -> URec Double b -> URec Double a #
Eq (URec Double p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: URec Double p -> URec Double p -> Bool # (/=) :: URec Double p -> URec Double p -> Bool #
Ord (URec Double p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: URec Double p -> URec Double p -> Ordering # (<) :: URec Double p -> URec Double p -> Bool # (<=) :: URec Double p -> URec Double p -> Bool # (>) :: URec Double p -> URec Double p -> Bool # (>=) :: URec Double p -> URec Double p -> Bool # max :: URec Double p -> URec Double p -> URec Double p # min :: URec Double p -> URec Double p -> URec Double p #
Show (URec Double p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Double p -> ShowS # show :: URec Double p -> String # showList :: [URec Double p] -> ShowS #
Generic (URec Double p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (URec Double p) :: Type -> Type # Methods from :: URec Double p -> Rep (URec Double p) x # to :: Rep (URec Double p) x -> URec Double p #
data URec Double (p :: k)	Used for marking occurrences of `Double#` Since: base-4.9.0.0
Instance details Defined in GHC.Generics data URec Double (p :: k) = UDouble { uDouble# :: Double# }
type Rep1 (URec Double :: k -> Type)
Instance details Defined in GHC.Generics type Rep1 (URec Double :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UDouble" 'PrefixI 'True) (S1 ('MetaSel ('Just "uDouble#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UDouble :: k -> Type)))
type Rep (URec Double p)
Instance details Defined in GHC.Generics type Rep (URec Double p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UDouble" 'PrefixI 'True) (S1 ('MetaSel ('Just "uDouble#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UDouble :: Type -> Type)))

Numeric type classes

Num

class Num a where #

Basic numeric class.

The Haskell Report defines no laws for Num. However, (+) and (*) are customarily expected to define a ring and have the following properties:

Associativity of (+): (x + y) + z = x + (y + z)
Commutativity of (+): x + y = y + x
fromInteger 0 is the additive identity: x + fromInteger 0 = x
negate gives the additive inverse: x + negate x = fromInteger 0
Associativity of (*): (x * y) * z = x * (y * z)
fromInteger 1 is the multiplicative identity: x * fromInteger 1 = x and fromInteger 1 * x = x
Distributivity of (*) with respect to (+): a * (b + c) = (a * b) + (a * c) and (b + c) * a = (b * a) + (c * a)

Note that it isn't customarily expected that a type instance of both Num and Ord implement an ordered ring. Indeed, in base only Integer and Rational do.

Minimal complete definition

(+), (*), abs, signum, fromInteger, (negate | (-))

Methods

(+) :: a -> a -> a infixl 6 #

(-) :: a -> a -> a infixl 6 #

(*) :: a -> a -> a infixl 7 #

negate :: a -> a #

Unary negation.

abs :: a -> a #

Absolute value.

signum :: a -> a #

Sign of a number. The functions abs and signum should satisfy the law:

abs x * signum x == x

For real numbers, the signum is either -1 (negative), 0 (zero) or 1 (positive).

fromInteger :: Integer -> a #

Conversion from an Integer. An integer literal represents the application of the function fromInteger to the appropriate value of type Integer, so such literals have type (Num a) => a.

Instances

Instances details

Num Int	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Int -> Int -> Int # (-) :: Int -> Int -> Int # (*) :: Int -> Int -> Int # negate :: Int -> Int # abs :: Int -> Int # signum :: Int -> Int # fromInteger :: Integer -> Int #
Num Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods (+) :: Int8 -> Int8 -> Int8 # (-) :: Int8 -> Int8 -> Int8 # (*) :: Int8 -> Int8 -> Int8 # negate :: Int8 -> Int8 # abs :: Int8 -> Int8 # signum :: Int8 -> Int8 # fromInteger :: Integer -> Int8 #
Num Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods (+) :: Int16 -> Int16 -> Int16 # (-) :: Int16 -> Int16 -> Int16 # (*) :: Int16 -> Int16 -> Int16 # negate :: Int16 -> Int16 # abs :: Int16 -> Int16 # signum :: Int16 -> Int16 # fromInteger :: Integer -> Int16 #
Num Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods (+) :: Int32 -> Int32 -> Int32 # (-) :: Int32 -> Int32 -> Int32 # (*) :: Int32 -> Int32 -> Int32 # negate :: Int32 -> Int32 # abs :: Int32 -> Int32 # signum :: Int32 -> Int32 # fromInteger :: Integer -> Int32 #
Num Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods (+) :: Int64 -> Int64 -> Int64 # (-) :: Int64 -> Int64 -> Int64 # (*) :: Int64 -> Int64 -> Int64 # negate :: Int64 -> Int64 # abs :: Int64 -> Int64 # signum :: Int64 -> Int64 # fromInteger :: Integer -> Int64 #
Num Integer	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Integer -> Integer -> Integer # (-) :: Integer -> Integer -> Integer # (*) :: Integer -> Integer -> Integer # negate :: Integer -> Integer # abs :: Integer -> Integer # signum :: Integer -> Integer # fromInteger :: Integer -> Integer #
Num Natural	Note that `Natural`'s `Num` instance isn't a ring: no element but 0 has an additive inverse. It is a semiring though. Since: base-4.8.0.0
Instance details Defined in GHC.Num Methods (+) :: Natural -> Natural -> Natural # (-) :: Natural -> Natural -> Natural # (*) :: Natural -> Natural -> Natural # negate :: Natural -> Natural # abs :: Natural -> Natural # signum :: Natural -> Natural # fromInteger :: Integer -> Natural #
Num Word	Since: base-2.1
Instance details Defined in GHC.Num Methods (+) :: Word -> Word -> Word # (-) :: Word -> Word -> Word # (*) :: Word -> Word -> Word # negate :: Word -> Word # abs :: Word -> Word # signum :: Word -> Word # fromInteger :: Integer -> Word #
Num Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods (+) :: Word8 -> Word8 -> Word8 # (-) :: Word8 -> Word8 -> Word8 # (*) :: Word8 -> Word8 -> Word8 # negate :: Word8 -> Word8 # abs :: Word8 -> Word8 # signum :: Word8 -> Word8 # fromInteger :: Integer -> Word8 #
Num Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods (+) :: Word16 -> Word16 -> Word16 # (-) :: Word16 -> Word16 -> Word16 # (*) :: Word16 -> Word16 -> Word16 # negate :: Word16 -> Word16 # abs :: Word16 -> Word16 # signum :: Word16 -> Word16 # fromInteger :: Integer -> Word16 #
Num Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods (+) :: Word32 -> Word32 -> Word32 # (-) :: Word32 -> Word32 -> Word32 # (*) :: Word32 -> Word32 -> Word32 # negate :: Word32 -> Word32 # abs :: Word32 -> Word32 # signum :: Word32 -> Word32 # fromInteger :: Integer -> Word32 #
Num Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods (+) :: Word64 -> Word64 -> Word64 # (-) :: Word64 -> Word64 -> Word64 # (*) :: Word64 -> Word64 -> Word64 # negate :: Word64 -> Word64 # abs :: Word64 -> Word64 # signum :: Word64 -> Word64 # fromInteger :: Integer -> Word64 #
Num NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (+) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # (-) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # (*) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # negate :: NominalDiffTime -> NominalDiffTime # abs :: NominalDiffTime -> NominalDiffTime # signum :: NominalDiffTime -> NominalDiffTime # fromInteger :: Integer -> NominalDiffTime #
Num DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods (+) :: DiffTime -> DiffTime -> DiffTime # (-) :: DiffTime -> DiffTime -> DiffTime # (*) :: DiffTime -> DiffTime -> DiffTime # negate :: DiffTime -> DiffTime # abs :: DiffTime -> DiffTime # signum :: DiffTime -> DiffTime # fromInteger :: Integer -> DiffTime #
Num CodePoint
Instance details Defined in Data.Text.Encoding Methods (+) :: CodePoint -> CodePoint -> CodePoint # (-) :: CodePoint -> CodePoint -> CodePoint # (*) :: CodePoint -> CodePoint -> CodePoint # negate :: CodePoint -> CodePoint # abs :: CodePoint -> CodePoint # signum :: CodePoint -> CodePoint # fromInteger :: Integer -> CodePoint #
Num DecoderState
Instance details Defined in Data.Text.Encoding Methods (+) :: DecoderState -> DecoderState -> DecoderState # (-) :: DecoderState -> DecoderState -> DecoderState # (*) :: DecoderState -> DecoderState -> DecoderState # negate :: DecoderState -> DecoderState # abs :: DecoderState -> DecoderState # signum :: DecoderState -> DecoderState # fromInteger :: Integer -> DecoderState #
Integral a => Num (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods (+) :: Ratio a -> Ratio a -> Ratio a # (-) :: Ratio a -> Ratio a -> Ratio a # (*) :: Ratio a -> Ratio a -> Ratio a # negate :: Ratio a -> Ratio a # abs :: Ratio a -> Ratio a # signum :: Ratio a -> Ratio a # fromInteger :: Integer -> Ratio a #
Num a => Num (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (+) :: Min a -> Min a -> Min a # (-) :: Min a -> Min a -> Min a # (*) :: Min a -> Min a -> Min a # negate :: Min a -> Min a # abs :: Min a -> Min a # signum :: Min a -> Min a # fromInteger :: Integer -> Min a #
Num a => Num (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (+) :: Max a -> Max a -> Max a # (-) :: Max a -> Max a -> Max a # (*) :: Max a -> Max a -> Max a # negate :: Max a -> Max a # abs :: Max a -> Max a # signum :: Max a -> Max a # fromInteger :: Integer -> Max a #
Num a => Num (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods (+) :: Identity a -> Identity a -> Identity a # (-) :: Identity a -> Identity a -> Identity a # (*) :: Identity a -> Identity a -> Identity a # negate :: Identity a -> Identity a # abs :: Identity a -> Identity a # signum :: Identity a -> Identity a # fromInteger :: Integer -> Identity a #
Num a => Num (Sum a)	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Methods (+) :: Sum a -> Sum a -> Sum a # (-) :: Sum a -> Sum a -> Sum a # (*) :: Sum a -> Sum a -> Sum a # negate :: Sum a -> Sum a # abs :: Sum a -> Sum a # signum :: Sum a -> Sum a # fromInteger :: Integer -> Sum a #
Num a => Num (Product a)	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Methods (+) :: Product a -> Product a -> Product a # (-) :: Product a -> Product a -> Product a # (*) :: Product a -> Product a -> Product a # negate :: Product a -> Product a # abs :: Product a -> Product a # signum :: Product a -> Product a # fromInteger :: Integer -> Product a #
Num a => Num (Down a)	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods (+) :: Down a -> Down a -> Down a # (-) :: Down a -> Down a -> Down a # (*) :: Down a -> Down a -> Down a # negate :: Down a -> Down a # abs :: Down a -> Down a # signum :: Down a -> Down a # fromInteger :: Integer -> Down a #
Num a => Num (Op a b)
Instance details Defined in Data.Functor.Contravariant Methods (+) :: Op a b -> Op a b -> Op a b # (-) :: Op a b -> Op a b -> Op a b # (*) :: Op a b -> Op a b -> Op a b # negate :: Op a b -> Op a b # abs :: Op a b -> Op a b # signum :: Op a b -> Op a b # fromInteger :: Integer -> Op a b #
Num a => Num (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (+) :: Const a b -> Const a b -> Const a b # (-) :: Const a b -> Const a b -> Const a b # (*) :: Const a b -> Const a b -> Const a b # negate :: Const a b -> Const a b # abs :: Const a b -> Const a b # signum :: Const a b -> Const a b # fromInteger :: Integer -> Const a b #
(Applicative f, Num a) => Num (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods (+) :: Ap f a -> Ap f a -> Ap f a # (-) :: Ap f a -> Ap f a -> Ap f a # (*) :: Ap f a -> Ap f a -> Ap f a # negate :: Ap f a -> Ap f a # abs :: Ap f a -> Ap f a # signum :: Ap f a -> Ap f a # fromInteger :: Integer -> Ap f a #
Num (f a) => Num (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (+) :: Alt f a -> Alt f a -> Alt f a # (-) :: Alt f a -> Alt f a -> Alt f a # (*) :: Alt f a -> Alt f a -> Alt f a # negate :: Alt f a -> Alt f a # abs :: Alt f a -> Alt f a # signum :: Alt f a -> Alt f a # fromInteger :: Integer -> Alt f a #

subtract :: Num a => a -> a -> a #

the same as flip (-).

Because - is treated specially in the Haskell grammar, (- e) is not a section, but an application of prefix negation. However, (subtract exp) is equivalent to the disallowed section.

(^) :: (Num a, Integral b) => a -> b -> a infixr 8 #

raise a number to a non-negative integral power

Real

class (Num a, Ord a) => Real a where #

Methods

toRational :: a -> Rational #

the rational equivalent of its real argument with full precision

Instances

Instances details

Real Int	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Int -> Rational #
Real Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods toRational :: Int8 -> Rational #
Real Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods toRational :: Int16 -> Rational #
Real Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods toRational :: Int32 -> Rational #
Real Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods toRational :: Int64 -> Rational #
Real Integer	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Integer -> Rational #
Real Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Real Methods toRational :: Natural -> Rational #
Real Word	Since: base-2.1
Instance details Defined in GHC.Real Methods toRational :: Word -> Rational #
Real Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods toRational :: Word8 -> Rational #
Real Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods toRational :: Word16 -> Rational #
Real Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods toRational :: Word32 -> Rational #
Real Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods toRational :: Word64 -> Rational #
Real NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods toRational :: NominalDiffTime -> Rational #
Real DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods toRational :: DiffTime -> Rational #
Integral a => Real (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods toRational :: Ratio a -> Rational #
Real a => Real (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods toRational :: Identity a -> Rational #
Real a => Real (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods toRational :: Down a -> Rational #
Real a => Real (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods toRational :: Const a b -> Rational #

realToFrac :: (Real a, Fractional b) => a -> b #

general coercion to fractional types

Integral

class (Real a, Enum a) => Integral a where #

Integral numbers, supporting integer division.

The Haskell Report defines no laws for Integral. However, Integral instances are customarily expected to define a Euclidean domain and have the following properties for the div/mod and quot/rem pairs, given suitable Euclidean functions f and g:

x = y * quot x y + rem x y with rem x y = fromInteger 0 or g (rem x y) < g y
x = y * div x y + mod x y with mod x y = fromInteger 0 or f (mod x y) < f y

An example of a suitable Euclidean function, for Integer's instance, is abs.

Minimal complete definition

quotRem, toInteger

Methods

quot :: a -> a -> a infixl 7 #

integer division truncated toward zero

rem :: a -> a -> a infixl 7 #

integer remainder, satisfying

(x `quot` y)*y + (x `rem` y) == x

div :: a -> a -> a infixl 7 #

integer division truncated toward negative infinity

mod :: a -> a -> a infixl 7 #

integer modulus, satisfying

(x `div` y)*y + (x `mod` y) == x

quotRem :: a -> a -> (a, a) #

simultaneous quot and rem

divMod :: a -> a -> (a, a) #

simultaneous div and mod

toInteger :: a -> Integer #

conversion to Integer

Instances

Instances details

Integral Int	Since: base-2.0.1
Instance details Defined in GHC.Real Methods quot :: Int -> Int -> Int # rem :: Int -> Int -> Int # div :: Int -> Int -> Int # mod :: Int -> Int -> Int # quotRem :: Int -> Int -> (Int, Int) # divMod :: Int -> Int -> (Int, Int) # toInteger :: Int -> Integer #
Integral Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods quot :: Int8 -> Int8 -> Int8 # rem :: Int8 -> Int8 -> Int8 # div :: Int8 -> Int8 -> Int8 # mod :: Int8 -> Int8 -> Int8 # quotRem :: Int8 -> Int8 -> (Int8, Int8) # divMod :: Int8 -> Int8 -> (Int8, Int8) # toInteger :: Int8 -> Integer #
Integral Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods quot :: Int16 -> Int16 -> Int16 # rem :: Int16 -> Int16 -> Int16 # div :: Int16 -> Int16 -> Int16 # mod :: Int16 -> Int16 -> Int16 # quotRem :: Int16 -> Int16 -> (Int16, Int16) # divMod :: Int16 -> Int16 -> (Int16, Int16) # toInteger :: Int16 -> Integer #
Integral Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods quot :: Int32 -> Int32 -> Int32 # rem :: Int32 -> Int32 -> Int32 # div :: Int32 -> Int32 -> Int32 # mod :: Int32 -> Int32 -> Int32 # quotRem :: Int32 -> Int32 -> (Int32, Int32) # divMod :: Int32 -> Int32 -> (Int32, Int32) # toInteger :: Int32 -> Integer #
Integral Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods quot :: Int64 -> Int64 -> Int64 # rem :: Int64 -> Int64 -> Int64 # div :: Int64 -> Int64 -> Int64 # mod :: Int64 -> Int64 -> Int64 # quotRem :: Int64 -> Int64 -> (Int64, Int64) # divMod :: Int64 -> Int64 -> (Int64, Int64) # toInteger :: Int64 -> Integer #
Integral Integer	Since: base-2.0.1
Instance details Defined in GHC.Real Methods quot :: Integer -> Integer -> Integer # rem :: Integer -> Integer -> Integer # div :: Integer -> Integer -> Integer # mod :: Integer -> Integer -> Integer # quotRem :: Integer -> Integer -> (Integer, Integer) # divMod :: Integer -> Integer -> (Integer, Integer) # toInteger :: Integer -> Integer #
Integral Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Real Methods quot :: Natural -> Natural -> Natural # rem :: Natural -> Natural -> Natural # div :: Natural -> Natural -> Natural # mod :: Natural -> Natural -> Natural # quotRem :: Natural -> Natural -> (Natural, Natural) # divMod :: Natural -> Natural -> (Natural, Natural) # toInteger :: Natural -> Integer #
Integral Word	Since: base-2.1
Instance details Defined in GHC.Real Methods quot :: Word -> Word -> Word # rem :: Word -> Word -> Word # div :: Word -> Word -> Word # mod :: Word -> Word -> Word # quotRem :: Word -> Word -> (Word, Word) # divMod :: Word -> Word -> (Word, Word) # toInteger :: Word -> Integer #
Integral Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods quot :: Word8 -> Word8 -> Word8 # rem :: Word8 -> Word8 -> Word8 # div :: Word8 -> Word8 -> Word8 # mod :: Word8 -> Word8 -> Word8 # quotRem :: Word8 -> Word8 -> (Word8, Word8) # divMod :: Word8 -> Word8 -> (Word8, Word8) # toInteger :: Word8 -> Integer #
Integral Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods quot :: Word16 -> Word16 -> Word16 # rem :: Word16 -> Word16 -> Word16 # div :: Word16 -> Word16 -> Word16 # mod :: Word16 -> Word16 -> Word16 # quotRem :: Word16 -> Word16 -> (Word16, Word16) # divMod :: Word16 -> Word16 -> (Word16, Word16) # toInteger :: Word16 -> Integer #
Integral Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods quot :: Word32 -> Word32 -> Word32 # rem :: Word32 -> Word32 -> Word32 # div :: Word32 -> Word32 -> Word32 # mod :: Word32 -> Word32 -> Word32 # quotRem :: Word32 -> Word32 -> (Word32, Word32) # divMod :: Word32 -> Word32 -> (Word32, Word32) # toInteger :: Word32 -> Integer #
Integral Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods quot :: Word64 -> Word64 -> Word64 # rem :: Word64 -> Word64 -> Word64 # div :: Word64 -> Word64 -> Word64 # mod :: Word64 -> Word64 -> Word64 # quotRem :: Word64 -> Word64 -> (Word64, Word64) # divMod :: Word64 -> Word64 -> (Word64, Word64) # toInteger :: Word64 -> Integer #
Integral a => Integral (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods quot :: Identity a -> Identity a -> Identity a # rem :: Identity a -> Identity a -> Identity a # div :: Identity a -> Identity a -> Identity a # mod :: Identity a -> Identity a -> Identity a # quotRem :: Identity a -> Identity a -> (Identity a, Identity a) # divMod :: Identity a -> Identity a -> (Identity a, Identity a) # toInteger :: Identity a -> Integer #
Integral a => Integral (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods quot :: Down a -> Down a -> Down a # rem :: Down a -> Down a -> Down a # div :: Down a -> Down a -> Down a # mod :: Down a -> Down a -> Down a # quotRem :: Down a -> Down a -> (Down a, Down a) # divMod :: Down a -> Down a -> (Down a, Down a) # toInteger :: Down a -> Integer #
Integral a => Integral (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods quot :: Const a b -> Const a b -> Const a b # rem :: Const a b -> Const a b -> Const a b # div :: Const a b -> Const a b -> Const a b # mod :: Const a b -> Const a b -> Const a b # quotRem :: Const a b -> Const a b -> (Const a b, Const a b) # divMod :: Const a b -> Const a b -> (Const a b, Const a b) # toInteger :: Const a b -> Integer #

toIntegralSized :: (Integral a, Integral b, Bits a, Bits b) => a -> Maybe b #

Attempt to convert an Integral type a to an Integral type b using the size of the types as measured by Bits methods.

A simpler version of this function is:

toIntegral :: (Integral a, Integral b) => a -> Maybe b
toIntegral x
  | toInteger x == y = Just (fromInteger y)
  | otherwise        = Nothing
  where
    y = toInteger x

This version requires going through Integer, which can be inefficient. However, toIntegralSized is optimized to allow GHC to statically determine the relative type sizes (as measured by bitSizeMaybe and isSigned) and avoid going through Integer for many types. (The implementation uses fromIntegral, which is itself optimized with rules for base types but may go through Integer for some type pairs.)

Since: base-4.8.0.0

even :: Integral a => a -> Bool #

odd :: Integral a => a -> Bool #

Fractional

class Num a => Fractional a where #

Fractional numbers, supporting real division.

The Haskell Report defines no laws for Fractional. However, (+) and (*) are customarily expected to define a division ring and have the following properties:

recip gives the multiplicative inverse: x * recip x = recip x * x = fromInteger 1

Note that it isn't customarily expected that a type instance of Fractional implement a field. However, all instances in base do.

Minimal complete definition

fromRational, (recip | (/))

Methods

(/) :: a -> a -> a infixl 7 #

Fractional division.

recip :: a -> a #

Reciprocal fraction.

fromRational :: Rational -> a #

Conversion from a Rational (that is Ratio Integer). A floating literal stands for an application of fromRational to a value of type Rational, so such literals have type (Fractional a) => a.

Instances

Instances details

Fractional NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (/) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # recip :: NominalDiffTime -> NominalDiffTime # fromRational :: Rational -> NominalDiffTime #
Fractional DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods (/) :: DiffTime -> DiffTime -> DiffTime # recip :: DiffTime -> DiffTime # fromRational :: Rational -> DiffTime #
Integral a => Fractional (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods (/) :: Ratio a -> Ratio a -> Ratio a # recip :: Ratio a -> Ratio a # fromRational :: Rational -> Ratio a #
Fractional a => Fractional (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods (/) :: Identity a -> Identity a -> Identity a # recip :: Identity a -> Identity a # fromRational :: Rational -> Identity a #
Fractional a => Fractional (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods (/) :: Down a -> Down a -> Down a # recip :: Down a -> Down a # fromRational :: Rational -> Down a #
Fractional a => Fractional (Op a b)
Instance details Defined in Data.Functor.Contravariant Methods (/) :: Op a b -> Op a b -> Op a b # recip :: Op a b -> Op a b # fromRational :: Rational -> Op a b #
Fractional a => Fractional (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (/) :: Const a b -> Const a b -> Const a b # recip :: Const a b -> Const a b # fromRational :: Rational -> Const a b #

(^^) :: (Fractional a, Integral b) => a -> b -> a infixr 8 #

raise a number to an integral power

Floating

class Fractional a => Floating a where #

Trigonometric and hyperbolic functions and related functions.

The Haskell Report defines no laws for Floating. However, (+), (*) and exp are customarily expected to define an exponential field and have the following properties:

exp (a + b) = exp a * exp b
exp (fromInteger 0) = fromInteger 1

Minimal complete definition

pi, exp, log, sin, cos, asin, acos, atan, sinh, cosh, asinh, acosh, atanh

Methods

pi :: a #

exp :: a -> a #

log :: a -> a #

sqrt :: a -> a #

(**) :: a -> a -> a infixr 8 #

logBase :: a -> a -> a #

sin :: a -> a #

cos :: a -> a #

tan :: a -> a #

asin :: a -> a #

acos :: a -> a #

atan :: a -> a #

sinh :: a -> a #

cosh :: a -> a #

tanh :: a -> a #

asinh :: a -> a #

acosh :: a -> a #

atanh :: a -> a #

Instances

Instances details

Floating Double	Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Double # exp :: Double -> Double # log :: Double -> Double # sqrt :: Double -> Double # (**) :: Double -> Double -> Double # logBase :: Double -> Double -> Double # sin :: Double -> Double # cos :: Double -> Double # tan :: Double -> Double # asin :: Double -> Double # acos :: Double -> Double # atan :: Double -> Double # sinh :: Double -> Double # cosh :: Double -> Double # tanh :: Double -> Double # asinh :: Double -> Double # acosh :: Double -> Double # atanh :: Double -> Double # log1p :: Double -> Double # expm1 :: Double -> Double # log1pexp :: Double -> Double # log1mexp :: Double -> Double #
Floating Float	Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Float # exp :: Float -> Float # log :: Float -> Float # sqrt :: Float -> Float # (**) :: Float -> Float -> Float # logBase :: Float -> Float -> Float # sin :: Float -> Float # cos :: Float -> Float # tan :: Float -> Float # asin :: Float -> Float # acos :: Float -> Float # atan :: Float -> Float # sinh :: Float -> Float # cosh :: Float -> Float # tanh :: Float -> Float # asinh :: Float -> Float # acosh :: Float -> Float # atanh :: Float -> Float # log1p :: Float -> Float # expm1 :: Float -> Float # log1pexp :: Float -> Float # log1mexp :: Float -> Float #
Floating a => Floating (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods pi :: Identity a # exp :: Identity a -> Identity a # log :: Identity a -> Identity a # sqrt :: Identity a -> Identity a # (**) :: Identity a -> Identity a -> Identity a # logBase :: Identity a -> Identity a -> Identity a # sin :: Identity a -> Identity a # cos :: Identity a -> Identity a # tan :: Identity a -> Identity a # asin :: Identity a -> Identity a # acos :: Identity a -> Identity a # atan :: Identity a -> Identity a # sinh :: Identity a -> Identity a # cosh :: Identity a -> Identity a # tanh :: Identity a -> Identity a # asinh :: Identity a -> Identity a # acosh :: Identity a -> Identity a # atanh :: Identity a -> Identity a # log1p :: Identity a -> Identity a # expm1 :: Identity a -> Identity a # log1pexp :: Identity a -> Identity a # log1mexp :: Identity a -> Identity a #
Floating a => Floating (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods pi :: Down a # exp :: Down a -> Down a # log :: Down a -> Down a # sqrt :: Down a -> Down a # (**) :: Down a -> Down a -> Down a # logBase :: Down a -> Down a -> Down a # sin :: Down a -> Down a # cos :: Down a -> Down a # tan :: Down a -> Down a # asin :: Down a -> Down a # acos :: Down a -> Down a # atan :: Down a -> Down a # sinh :: Down a -> Down a # cosh :: Down a -> Down a # tanh :: Down a -> Down a # asinh :: Down a -> Down a # acosh :: Down a -> Down a # atanh :: Down a -> Down a # log1p :: Down a -> Down a # expm1 :: Down a -> Down a # log1pexp :: Down a -> Down a # log1mexp :: Down a -> Down a #
Floating a => Floating (Op a b)
Instance details Defined in Data.Functor.Contravariant Methods pi :: Op a b # exp :: Op a b -> Op a b # log :: Op a b -> Op a b # sqrt :: Op a b -> Op a b # (**) :: Op a b -> Op a b -> Op a b # logBase :: Op a b -> Op a b -> Op a b # sin :: Op a b -> Op a b # cos :: Op a b -> Op a b # tan :: Op a b -> Op a b # asin :: Op a b -> Op a b # acos :: Op a b -> Op a b # atan :: Op a b -> Op a b # sinh :: Op a b -> Op a b # cosh :: Op a b -> Op a b # tanh :: Op a b -> Op a b # asinh :: Op a b -> Op a b # acosh :: Op a b -> Op a b # atanh :: Op a b -> Op a b # log1p :: Op a b -> Op a b # expm1 :: Op a b -> Op a b # log1pexp :: Op a b -> Op a b # log1mexp :: Op a b -> Op a b #
Floating a => Floating (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods pi :: Const a b # exp :: Const a b -> Const a b # log :: Const a b -> Const a b # sqrt :: Const a b -> Const a b # (**) :: Const a b -> Const a b -> Const a b # logBase :: Const a b -> Const a b -> Const a b # sin :: Const a b -> Const a b # cos :: Const a b -> Const a b # tan :: Const a b -> Const a b # asin :: Const a b -> Const a b # acos :: Const a b -> Const a b # atan :: Const a b -> Const a b # sinh :: Const a b -> Const a b # cosh :: Const a b -> Const a b # tanh :: Const a b -> Const a b # asinh :: Const a b -> Const a b # acosh :: Const a b -> Const a b # atanh :: Const a b -> Const a b # log1p :: Const a b -> Const a b # expm1 :: Const a b -> Const a b # log1pexp :: Const a b -> Const a b # log1mexp :: Const a b -> Const a b #

RealFrac

class (Real a, Fractional a) => RealFrac a where #

Extracting components of fractions.

Minimal complete definition

properFraction

Methods

properFraction :: Integral b => a -> (b, a) #

The function properFraction takes a real fractional number x and returns a pair (n,f) such that x = n+f, and:

n is an integral number with the same sign as x; and
f is a fraction with the same type and sign as x, and with absolute value less than 1.

The default definitions of the ceiling, floor, truncate and round functions are in terms of properFraction.

truncate :: Integral b => a -> b #

truncate x returns the integer nearest x between zero and x

round :: Integral b => a -> b #

round x returns the nearest integer to x; the even integer if x is equidistant between two integers

ceiling :: Integral b => a -> b #

ceiling x returns the least integer not less than x

floor :: Integral b => a -> b #

floor x returns the greatest integer not greater than x

Instances

Instances details

RealFrac NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods properFraction :: Integral b => NominalDiffTime -> (b, NominalDiffTime) # truncate :: Integral b => NominalDiffTime -> b # round :: Integral b => NominalDiffTime -> b # ceiling :: Integral b => NominalDiffTime -> b # floor :: Integral b => NominalDiffTime -> b #
RealFrac DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods properFraction :: Integral b => DiffTime -> (b, DiffTime) # truncate :: Integral b => DiffTime -> b # round :: Integral b => DiffTime -> b # ceiling :: Integral b => DiffTime -> b # floor :: Integral b => DiffTime -> b #
Integral a => RealFrac (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods properFraction :: Integral b => Ratio a -> (b, Ratio a) # truncate :: Integral b => Ratio a -> b # round :: Integral b => Ratio a -> b # ceiling :: Integral b => Ratio a -> b # floor :: Integral b => Ratio a -> b #
RealFrac a => RealFrac (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods properFraction :: Integral b => Identity a -> (b, Identity a) # truncate :: Integral b => Identity a -> b # round :: Integral b => Identity a -> b # ceiling :: Integral b => Identity a -> b # floor :: Integral b => Identity a -> b #
RealFrac a => RealFrac (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods properFraction :: Integral b => Down a -> (b, Down a) # truncate :: Integral b => Down a -> b # round :: Integral b => Down a -> b # ceiling :: Integral b => Down a -> b # floor :: Integral b => Down a -> b #
RealFrac a => RealFrac (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods properFraction :: Integral b0 => Const a b -> (b0, Const a b) # truncate :: Integral b0 => Const a b -> b0 # round :: Integral b0 => Const a b -> b0 # ceiling :: Integral b0 => Const a b -> b0 # floor :: Integral b0 => Const a b -> b0 #

RealFloat

class (RealFrac a, Floating a) => RealFloat a where #

Efficient, machine-independent access to the components of a floating-point number.

Minimal complete definition

floatRadix, floatDigits, floatRange, decodeFloat, encodeFloat, isNaN, isInfinite, isDenormalized, isNegativeZero, isIEEE

Methods

floatRadix :: a -> Integer #

a constant function, returning the radix of the representation (often 2)

floatDigits :: a -> Int #

a constant function, returning the number of digits of floatRadix in the significand

floatRange :: a -> (Int, Int) #

a constant function, returning the lowest and highest values the exponent may assume

decodeFloat :: a -> (Integer, Int) #

The function decodeFloat applied to a real floating-point number returns the significand expressed as an Integer and an appropriately scaled exponent (an Int). If decodeFloat x yields (m,n), then x is equal in value to m*b^^n, where b is the floating-point radix, and furthermore, either m and n are both zero or else b^(d-1) <= abs m < b^d, where d is the value of floatDigits x. In particular, decodeFloat 0 = (0,0). If the type contains a negative zero, also decodeFloat (-0.0) = (0,0). The result of decodeFloat x is unspecified if either of isNaN x or isInfinite x is True.

encodeFloat :: Integer -> Int -> a #

encodeFloat performs the inverse of decodeFloat in the sense that for finite x with the exception of -0.0, uncurry encodeFloat (decodeFloat x) = x. encodeFloat m n is one of the two closest representable floating-point numbers to m*b^^n (or ±Infinity if overflow occurs); usually the closer, but if m contains too many bits, the result may be rounded in the wrong direction.

exponent :: a -> Int #

exponent corresponds to the second component of decodeFloat. exponent 0 = 0 and for finite nonzero x, exponent x = snd (decodeFloat x) + floatDigits x. If x is a finite floating-point number, it is equal in value to significand x * b ^^ exponent x, where b is the floating-point radix. The behaviour is unspecified on infinite or NaN values.

significand :: a -> a #

The first component of decodeFloat, scaled to lie in the open interval (-1,1), either 0.0 or of absolute value >= 1/b, where b is the floating-point radix. The behaviour is unspecified on infinite or NaN values.

scaleFloat :: Int -> a -> a #

multiplies a floating-point number by an integer power of the radix

isNaN :: a -> Bool #

True if the argument is an IEEE "not-a-number" (NaN) value

isInfinite :: a -> Bool #

True if the argument is an IEEE infinity or negative infinity

isDenormalized :: a -> Bool #

True if the argument is too small to be represented in normalized format

isNegativeZero :: a -> Bool #

True if the argument is an IEEE negative zero

isIEEE :: a -> Bool #

True if the argument is an IEEE floating point number

atan2 :: a -> a -> a #

a version of arctangent taking two real floating-point arguments. For real floating x and y, atan2 y x computes the angle (from the positive x-axis) of the vector from the origin to the point (x,y). atan2 y x returns a value in the range [-pi, pi]. It follows the Common Lisp semantics for the origin when signed zeroes are supported. atan2 y 1, with y in a type that is RealFloat, should return the same value as atan y. A default definition of atan2 is provided, but implementors can provide a more accurate implementation.

Instances

Instances details

RealFloat Double	Since: base-2.1
Instance details Defined in GHC.Float Methods floatRadix :: Double -> Integer # floatDigits :: Double -> Int # floatRange :: Double -> (Int, Int) # decodeFloat :: Double -> (Integer, Int) # encodeFloat :: Integer -> Int -> Double # exponent :: Double -> Int # significand :: Double -> Double # scaleFloat :: Int -> Double -> Double # isNaN :: Double -> Bool # isInfinite :: Double -> Bool # isDenormalized :: Double -> Bool # isNegativeZero :: Double -> Bool # isIEEE :: Double -> Bool # atan2 :: Double -> Double -> Double #
RealFloat Float	Since: base-2.1
Instance details Defined in GHC.Float Methods floatRadix :: Float -> Integer # floatDigits :: Float -> Int # floatRange :: Float -> (Int, Int) # decodeFloat :: Float -> (Integer, Int) # encodeFloat :: Integer -> Int -> Float # exponent :: Float -> Int # significand :: Float -> Float # scaleFloat :: Int -> Float -> Float # isNaN :: Float -> Bool # isInfinite :: Float -> Bool # isDenormalized :: Float -> Bool # isNegativeZero :: Float -> Bool # isIEEE :: Float -> Bool # atan2 :: Float -> Float -> Float #
RealFloat a => RealFloat (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods floatRadix :: Identity a -> Integer # floatDigits :: Identity a -> Int # floatRange :: Identity a -> (Int, Int) # decodeFloat :: Identity a -> (Integer, Int) # encodeFloat :: Integer -> Int -> Identity a # exponent :: Identity a -> Int # significand :: Identity a -> Identity a # scaleFloat :: Int -> Identity a -> Identity a # isNaN :: Identity a -> Bool # isInfinite :: Identity a -> Bool # isDenormalized :: Identity a -> Bool # isNegativeZero :: Identity a -> Bool # isIEEE :: Identity a -> Bool # atan2 :: Identity a -> Identity a -> Identity a #
RealFloat a => RealFloat (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods floatRadix :: Down a -> Integer # floatDigits :: Down a -> Int # floatRange :: Down a -> (Int, Int) # decodeFloat :: Down a -> (Integer, Int) # encodeFloat :: Integer -> Int -> Down a # exponent :: Down a -> Int # significand :: Down a -> Down a # scaleFloat :: Int -> Down a -> Down a # isNaN :: Down a -> Bool # isInfinite :: Down a -> Bool # isDenormalized :: Down a -> Bool # isNegativeZero :: Down a -> Bool # isIEEE :: Down a -> Bool # atan2 :: Down a -> Down a -> Down a #
RealFloat a => RealFloat (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods floatRadix :: Const a b -> Integer # floatDigits :: Const a b -> Int # floatRange :: Const a b -> (Int, Int) # decodeFloat :: Const a b -> (Integer, Int) # encodeFloat :: Integer -> Int -> Const a b # exponent :: Const a b -> Int # significand :: Const a b -> Const a b # scaleFloat :: Int -> Const a b -> Const a b # isNaN :: Const a b -> Bool # isInfinite :: Const a b -> Bool # isDenormalized :: Const a b -> Bool # isNegativeZero :: Const a b -> Bool # isIEEE :: Const a b -> Bool # atan2 :: Const a b -> Const a b -> Const a b #

Read and Show

Show

class Show a #

Conversion of values to readable Strings.

Derived instances of Show have the following properties, which are compatible with derived instances of Read:

The result of show is a syntactically correct Haskell expression containing only constants, given the fixity declarations in force at the point where the type is declared. It contains only the constructor names defined in the data type, parentheses, and spaces. When labelled constructor fields are used, braces, commas, field names, and equal signs are also used.
If the constructor is defined to be an infix operator, then showsPrec will produce infix applications of the constructor.
the representation will be enclosed in parentheses if the precedence of the top-level constructor in x is less than d (associativity is ignored). Thus, if d is 0 then the result is never surrounded in parentheses; if d is 11 it is always surrounded in parentheses, unless it is an atomic expression.
If the constructor is defined using record syntax, then show will produce the record-syntax form, with the fields given in the same order as the original declaration.

For example, given the declarations

infixr 5 :^:
data Tree a =  Leaf a  |  Tree a :^: Tree a

the derived instance of Show is equivalent to

instance (Show a) => Show (Tree a) where

       showsPrec d (Leaf m) = showParen (d > app_prec) $
            showString "Leaf " . showsPrec (app_prec+1) m
         where app_prec = 10

       showsPrec d (u :^: v) = showParen (d > up_prec) $
            showsPrec (up_prec+1) u .
            showString " :^: "      .
            showsPrec (up_prec+1) v
         where up_prec = 5

Note that right-associativity of :^: is ignored. For example,

show (Leaf 1 :^: Leaf 2 :^: Leaf 3) produces the string "Leaf 1 :^: (Leaf 2 :^: Leaf 3)".

Minimal complete definition

showsPrec | show

Instances

Instances details

Show Bool	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Bool -> ShowS # show :: Bool -> String # showList :: [Bool] -> ShowS #
Show Char	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Char -> ShowS # show :: Char -> String # showList :: [Char] -> ShowS #
Show Int	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Int -> ShowS # show :: Int -> String # showList :: [Int] -> ShowS #
Show Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods showsPrec :: Int -> Int8 -> ShowS # show :: Int8 -> String # showList :: [Int8] -> ShowS #
Show Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods showsPrec :: Int -> Int16 -> ShowS # show :: Int16 -> String # showList :: [Int16] -> ShowS #
Show Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods showsPrec :: Int -> Int32 -> ShowS # show :: Int32 -> String # showList :: [Int32] -> ShowS #
Show Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods showsPrec :: Int -> Int64 -> ShowS # show :: Int64 -> String # showList :: [Int64] -> ShowS #
Show Integer	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Integer -> ShowS # show :: Integer -> String # showList :: [Integer] -> ShowS #
Show Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Natural -> ShowS # show :: Natural -> String # showList :: [Natural] -> ShowS #
Show Ordering	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Ordering -> ShowS # show :: Ordering -> String # showList :: [Ordering] -> ShowS #
Show Word	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Word -> ShowS # show :: Word -> String # showList :: [Word] -> ShowS #
Show Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods showsPrec :: Int -> Word8 -> ShowS # show :: Word8 -> String # showList :: [Word8] -> ShowS #
Show Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods showsPrec :: Int -> Word16 -> ShowS # show :: Word16 -> String # showList :: [Word16] -> ShowS #
Show Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods showsPrec :: Int -> Word32 -> ShowS # show :: Word32 -> String # showList :: [Word32] -> ShowS #
Show Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods showsPrec :: Int -> Word64 -> ShowS # show :: Word64 -> String # showList :: [Word64] -> ShowS #
Show RuntimeRep	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> RuntimeRep -> ShowS # show :: RuntimeRep -> String # showList :: [RuntimeRep] -> ShowS #
Show VecCount	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> VecCount -> ShowS # show :: VecCount -> String # showList :: [VecCount] -> ShowS #
Show VecElem	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> VecElem -> ShowS # show :: VecElem -> String # showList :: [VecElem] -> ShowS #
Show CallStack	Since: base-4.9.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> CallStack -> ShowS # show :: CallStack -> String # showList :: [CallStack] -> ShowS #
Show SomeTypeRep	Since: base-4.10.0.0
Instance details Defined in Data.Typeable.Internal Methods showsPrec :: Int -> SomeTypeRep -> ShowS # show :: SomeTypeRep -> String # showList :: [SomeTypeRep] -> ShowS #
Show ()	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> () -> ShowS # show :: () -> String # showList :: [()] -> ShowS #
Show TyCon	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> TyCon -> ShowS # show :: TyCon -> String # showList :: [TyCon] -> ShowS #
Show Module	Since: base-4.9.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Module -> ShowS # show :: Module -> String # showList :: [Module] -> ShowS #
Show TrName	Since: base-4.9.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> TrName -> ShowS # show :: TrName -> String # showList :: [TrName] -> ShowS #
Show KindRep
Instance details Defined in GHC.Show Methods showsPrec :: Int -> KindRep -> ShowS # show :: KindRep -> String # showList :: [KindRep] -> ShowS #
Show TypeLitSort	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> TypeLitSort -> ShowS # show :: TypeLitSort -> String # showList :: [TypeLitSort] -> ShowS #
Show Handle	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> Handle -> ShowS # show :: Handle -> String # showList :: [Handle] -> ShowS #
Show Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods showsPrec :: Int -> Void -> ShowS # show :: Void -> String # showList :: [Void] -> ShowS #
Show ThreadId	Since: base-4.2.0.0
Instance details Defined in GHC.Conc.Sync Methods showsPrec :: Int -> ThreadId -> ShowS # show :: ThreadId -> String # showList :: [ThreadId] -> ShowS #
Show BlockReason	Since: base-4.3.0.0
Instance details Defined in GHC.Conc.Sync Methods showsPrec :: Int -> BlockReason -> ShowS # show :: BlockReason -> String # showList :: [BlockReason] -> ShowS #
Show ThreadStatus	Since: base-4.3.0.0
Instance details Defined in GHC.Conc.Sync Methods showsPrec :: Int -> ThreadStatus -> ShowS # show :: ThreadStatus -> String # showList :: [ThreadStatus] -> ShowS #
Show BlockedIndefinitelyOnMVar	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> BlockedIndefinitelyOnMVar -> ShowS # show :: BlockedIndefinitelyOnMVar -> String # showList :: [BlockedIndefinitelyOnMVar] -> ShowS #
Show BlockedIndefinitelyOnSTM	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> BlockedIndefinitelyOnSTM -> ShowS # show :: BlockedIndefinitelyOnSTM -> String # showList :: [BlockedIndefinitelyOnSTM] -> ShowS #
Show Deadlock	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> Deadlock -> ShowS # show :: Deadlock -> String # showList :: [Deadlock] -> ShowS #
Show AllocationLimitExceeded	Since: base-4.7.1.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> AllocationLimitExceeded -> ShowS # show :: AllocationLimitExceeded -> String # showList :: [AllocationLimitExceeded] -> ShowS #
Show CompactionFailed	Since: base-4.10.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> CompactionFailed -> ShowS # show :: CompactionFailed -> String # showList :: [CompactionFailed] -> ShowS #
Show AssertionFailed	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> AssertionFailed -> ShowS # show :: AssertionFailed -> String # showList :: [AssertionFailed] -> ShowS #
Show SomeAsyncException	Since: base-4.7.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> SomeAsyncException -> ShowS # show :: SomeAsyncException -> String # showList :: [SomeAsyncException] -> ShowS #
Show AsyncException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> AsyncException -> ShowS # show :: AsyncException -> String # showList :: [AsyncException] -> ShowS #
Show ArrayException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> ArrayException -> ShowS # show :: ArrayException -> String # showList :: [ArrayException] -> ShowS #
Show FixIOException	Since: base-4.11.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> FixIOException -> ShowS # show :: FixIOException -> String # showList :: [FixIOException] -> ShowS #
Show ExitCode
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> ExitCode -> ShowS # show :: ExitCode -> String # showList :: [ExitCode] -> ShowS #
Show IOErrorType	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> IOErrorType -> ShowS # show :: IOErrorType -> String # showList :: [IOErrorType] -> ShowS #
Show HandleType	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> HandleType -> ShowS # show :: HandleType -> String # showList :: [HandleType] -> ShowS #
Show BufferMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> BufferMode -> ShowS # show :: BufferMode -> String # showList :: [BufferMode] -> ShowS #
Show Newline	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> Newline -> ShowS # show :: Newline -> String # showList :: [Newline] -> ShowS #
Show NewlineMode	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> NewlineMode -> ShowS # show :: NewlineMode -> String # showList :: [NewlineMode] -> ShowS #
Show MaskingState	Since: base-4.3.0.0
Instance details Defined in GHC.IO Methods showsPrec :: Int -> MaskingState -> ShowS # show :: MaskingState -> String # showList :: [MaskingState] -> ShowS #
Show IOException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods showsPrec :: Int -> IOException -> ShowS # show :: IOException -> String # showList :: [IOException] -> ShowS #
Show ArithException	Since: base-4.0.0.0
Instance details Defined in GHC.Exception.Type Methods showsPrec :: Int -> ArithException -> ShowS # show :: ArithException -> String # showList :: [ArithException] -> ShowS #
Show All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> All -> ShowS # show :: All -> String # showList :: [All] -> ShowS #
Show Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> Any -> ShowS # show :: Any -> String # showList :: [Any] -> ShowS #
Show Fixity	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> Fixity -> ShowS # show :: Fixity -> String # showList :: [Fixity] -> ShowS #
Show Associativity	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> Associativity -> ShowS # show :: Associativity -> String # showList :: [Associativity] -> ShowS #
Show SourceUnpackedness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> SourceUnpackedness -> ShowS # show :: SourceUnpackedness -> String # showList :: [SourceUnpackedness] -> ShowS #
Show SourceStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> SourceStrictness -> ShowS # show :: SourceStrictness -> String # showList :: [SourceStrictness] -> ShowS #
Show DecidedStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> DecidedStrictness -> ShowS # show :: DecidedStrictness -> String # showList :: [DecidedStrictness] -> ShowS #
Show SrcLoc	Since: base-4.9.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> SrcLoc -> ShowS # show :: SrcLoc -> String # showList :: [SrcLoc] -> ShowS #
Show SomeException	Since: base-3.0
Instance details Defined in GHC.Exception.Type Methods showsPrec :: Int -> SomeException -> ShowS # show :: SomeException -> String # showList :: [SomeException] -> ShowS #
Show ByteString
Instance details Defined in Data.ByteString.Lazy.Internal Methods showsPrec :: Int -> ByteString -> ShowS # show :: ByteString -> String # showList :: [ByteString] -> ShowS #
Show ByteString
Instance details Defined in Data.ByteString.Internal Methods showsPrec :: Int -> ByteString -> ShowS # show :: ByteString -> String # showList :: [ByteString] -> ShowS #
Show Decoding
Instance details Defined in Data.Text.Encoding Methods showsPrec :: Int -> Decoding -> ShowS # show :: Decoding -> String # showList :: [Decoding] -> ShowS #
Show UnicodeException
Instance details Defined in Data.Text.Encoding.Error Methods showsPrec :: Int -> UnicodeException -> ShowS # show :: UnicodeException -> String # showList :: [UnicodeException] -> ShowS #
Show ZonedTime
Instance details Defined in Data.Time.LocalTime.Internal.ZonedTime Methods showsPrec :: Int -> ZonedTime -> ShowS # show :: ZonedTime -> String # showList :: [ZonedTime] -> ShowS #
Show LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods showsPrec :: Int -> LocalTime -> ShowS # show :: LocalTime -> String # showList :: [LocalTime] -> ShowS #
Show TimeOfDay
Instance details Defined in Data.Time.LocalTime.Internal.TimeOfDay Methods showsPrec :: Int -> TimeOfDay -> ShowS # show :: TimeOfDay -> String # showList :: [TimeOfDay] -> ShowS #
Show NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods showsPrec :: Int -> NominalDiffTime -> ShowS # show :: NominalDiffTime -> String # showList :: [NominalDiffTime] -> ShowS #
Show DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods showsPrec :: Int -> DiffTime -> ShowS # show :: DiffTime -> String # showList :: [DiffTime] -> ShowS #
Show CodePoint
Instance details Defined in Data.Text.Encoding Methods showsPrec :: Int -> CodePoint -> ShowS # show :: CodePoint -> String # showList :: [CodePoint] -> ShowS #
Show DecoderState
Instance details Defined in Data.Text.Encoding Methods showsPrec :: Int -> DecoderState -> ShowS # show :: DecoderState -> String # showList :: [DecoderState] -> ShowS #
Show Leniency Source #
Instance details Defined in Verset.Conv Methods showsPrec :: Int -> Leniency -> ShowS # show :: Leniency -> String # showList :: [Leniency] -> ShowS #
Show UUID
Instance details Defined in Data.UUID.Types.Internal Methods showsPrec :: Int -> UUID -> ShowS # show :: UUID -> String # showList :: [UUID] -> ShowS #
Show UnpackedUUID
Instance details Defined in Data.UUID.Types.Internal Methods showsPrec :: Int -> UnpackedUUID -> ShowS # show :: UnpackedUUID -> String # showList :: [UnpackedUUID] -> ShowS #
Show a => Show [a]	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> [a] -> ShowS # show :: [a] -> String # showList :: [[a]] -> ShowS #
Show a => Show (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Maybe a -> ShowS # show :: Maybe a -> String # showList :: [Maybe a] -> ShowS #
Show a => Show (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods showsPrec :: Int -> Ratio a -> ShowS # show :: Ratio a -> String # showList :: [Ratio a] -> ShowS #
Show (Ptr a)	Since: base-2.1
Instance details Defined in GHC.Ptr Methods showsPrec :: Int -> Ptr a -> ShowS # show :: Ptr a -> String # showList :: [Ptr a] -> ShowS #
Show (FunPtr a)	Since: base-2.1
Instance details Defined in GHC.Ptr Methods showsPrec :: Int -> FunPtr a -> ShowS # show :: FunPtr a -> String # showList :: [FunPtr a] -> ShowS #
Show p => Show (Par1 p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> Par1 p -> ShowS # show :: Par1 p -> String # showList :: [Par1 p] -> ShowS #
Show a => Show (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> Min a -> ShowS # show :: Min a -> String # showList :: [Min a] -> ShowS #
Show a => Show (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> Max a -> ShowS # show :: Max a -> String # showList :: [Max a] -> ShowS #
Show a => Show (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> First a -> ShowS # show :: First a -> String # showList :: [First a] -> ShowS #
Show a => Show (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> Last a -> ShowS # show :: Last a -> String # showList :: [Last a] -> ShowS #
Show m => Show (WrappedMonoid m)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> WrappedMonoid m -> ShowS # show :: WrappedMonoid m -> String # showList :: [WrappedMonoid m] -> ShowS #
Show a => Show (Option a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> Option a -> ShowS # show :: Option a -> String # showList :: [Option a] -> ShowS #
Show a => Show (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods showsPrec :: Int -> ZipList a -> ShowS # show :: ZipList a -> String # showList :: [ZipList a] -> ShowS #
Show a => Show (Identity a)	This instance would be equivalent to the derived instances of the `Identity` newtype if the `runIdentity` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods showsPrec :: Int -> Identity a -> ShowS # show :: Identity a -> String # showList :: [Identity a] -> ShowS #
Show a => Show (First a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods showsPrec :: Int -> First a -> ShowS # show :: First a -> String # showList :: [First a] -> ShowS #
Show a => Show (Last a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods showsPrec :: Int -> Last a -> ShowS # show :: Last a -> String # showList :: [Last a] -> ShowS #
Show a => Show (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> Dual a -> ShowS # show :: Dual a -> String # showList :: [Dual a] -> ShowS #
Show a => Show (Sum a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> Sum a -> ShowS # show :: Sum a -> String # showList :: [Sum a] -> ShowS #
Show a => Show (Product a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> Product a -> ShowS # show :: Product a -> String # showList :: [Product a] -> ShowS #
Show a => Show (Down a)	This instance would be equivalent to the derived instances of the `Down` newtype if the `getDown` field were removed Since: base-4.7.0.0
Instance details Defined in Data.Ord Methods showsPrec :: Int -> Down a -> ShowS # show :: Down a -> String # showList :: [Down a] -> ShowS #
Show a => Show (NonEmpty a)	Since: base-4.11.0.0
Instance details Defined in GHC.Show Methods showsPrec :: Int -> NonEmpty a -> ShowS # show :: NonEmpty a -> String # showList :: [NonEmpty a] -> ShowS #
Show a => Show (Set a)
Instance details Defined in Data.Set.Internal Methods showsPrec :: Int -> Set a -> ShowS # show :: Set a -> String # showList :: [Set a] -> ShowS #
Show a => Show (RB a)
Instance details Defined in Data.List.Extra Methods showsPrec :: Int -> RB a -> ShowS # show :: RB a -> String # showList :: [RB a] -> ShowS #
(Show a, Show b) => Show (Either a b)	Since: base-3.0
Instance details Defined in Data.Either Methods showsPrec :: Int -> Either a b -> ShowS # show :: Either a b -> String # showList :: [Either a b] -> ShowS #
Show (V1 p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> V1 p -> ShowS # show :: V1 p -> String # showList :: [V1 p] -> ShowS #
Show (U1 p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> U1 p -> ShowS # show :: U1 p -> String # showList :: [U1 p] -> ShowS #
Show (TypeRep a)
Instance details Defined in Data.Typeable.Internal Methods showsPrec :: Int -> TypeRep a -> ShowS # show :: TypeRep a -> String # showList :: [TypeRep a] -> ShowS #
(Show a, Show b) => Show (a, b)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b) -> ShowS # show :: (a, b) -> String # showList :: [(a, b)] -> ShowS #
(Show a, Show b) => Show (Arg a b)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> Arg a b -> ShowS # show :: Arg a b -> String # showList :: [Arg a b] -> ShowS #
Show (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods showsPrec :: Int -> Proxy s -> ShowS # show :: Proxy s -> String # showList :: [Proxy s] -> ShowS #
(Show k, Show a) => Show (Map k a)
Instance details Defined in Data.Map.Internal Methods showsPrec :: Int -> Map k a -> ShowS # show :: Map k a -> String # showList :: [Map k a] -> ShowS #
Show (f p) => Show (Rec1 f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> Rec1 f p -> ShowS # show :: Rec1 f p -> String # showList :: [Rec1 f p] -> ShowS #
Show (URec Char p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Char p -> ShowS # show :: URec Char p -> String # showList :: [URec Char p] -> ShowS #
Show (URec Double p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Double p -> ShowS # show :: URec Double p -> String # showList :: [URec Double p] -> ShowS #
Show (URec Float p)
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Float p -> ShowS # show :: URec Float p -> String # showList :: [URec Float p] -> ShowS #
Show (URec Int p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Int p -> ShowS # show :: URec Int p -> String # showList :: [URec Int p] -> ShowS #
Show (URec Word p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> URec Word p -> ShowS # show :: URec Word p -> String # showList :: [URec Word p] -> ShowS #
(Show a, Show b, Show c) => Show (a, b, c)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c) -> ShowS # show :: (a, b, c) -> String # showList :: [(a, b, c)] -> ShowS #
Show a => Show (Const a b)	This instance would be equivalent to the derived instances of the `Const` newtype if the `getConst` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Const Methods showsPrec :: Int -> Const a b -> ShowS # show :: Const a b -> String # showList :: [Const a b] -> ShowS #
Show (f a) => Show (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods showsPrec :: Int -> Ap f a -> ShowS # show :: Ap f a -> String # showList :: [Ap f a] -> ShowS #
Show (f a) => Show (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> Alt f a -> ShowS # show :: Alt f a -> String # showList :: [Alt f a] -> ShowS #
(Show e, Show1 m, Show a) => Show (ErrorT e m a)
Instance details Defined in Control.Monad.Trans.Error Methods showsPrec :: Int -> ErrorT e m a -> ShowS # show :: ErrorT e m a -> String # showList :: [ErrorT e m a] -> ShowS #
Show c => Show (K1 i c p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> K1 i c p -> ShowS # show :: K1 i c p -> String # showList :: [K1 i c p] -> ShowS #
(Show (f p), Show (g p)) => Show ((f :+: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> (f :+: g) p -> ShowS # show :: (f :+: g) p -> String # showList :: [(f :+: g) p] -> ShowS #
(Show (f p), Show (g p)) => Show ((f :*: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> (f :: g) p -> ShowS # show :: (f :: g) p -> String # showList :: [(f :*: g) p] -> ShowS #
(Show a, Show b, Show c, Show d) => Show (a, b, c, d)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d) -> ShowS # show :: (a, b, c, d) -> String # showList :: [(a, b, c, d)] -> ShowS #
(Show1 f, Show1 g, Show a) => Show (Product f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods showsPrec :: Int -> Product f g a -> ShowS # show :: Product f g a -> String # showList :: [Product f g a] -> ShowS #
(Show1 f, Show1 g, Show a) => Show (Sum f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods showsPrec :: Int -> Sum f g a -> ShowS # show :: Sum f g a -> String # showList :: [Sum f g a] -> ShowS #
Show (f p) => Show (M1 i c f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> M1 i c f p -> ShowS # show :: M1 i c f p -> String # showList :: [M1 i c f p] -> ShowS #
Show (f (g p)) => Show ((f :.: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods showsPrec :: Int -> (f :.: g) p -> ShowS # show :: (f :.: g) p -> String # showList :: [(f :.: g) p] -> ShowS #
(Show a, Show b, Show c, Show d, Show e) => Show (a, b, c, d, e)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e) -> ShowS # show :: (a, b, c, d, e) -> String # showList :: [(a, b, c, d, e)] -> ShowS #
(Show1 f, Show1 g, Show a) => Show (Compose f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods showsPrec :: Int -> Compose f g a -> ShowS # show :: Compose f g a -> String # showList :: [Compose f g a] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f) => Show (a, b, c, d, e, f)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f) -> ShowS # show :: (a, b, c, d, e, f) -> String # showList :: [(a, b, c, d, e, f)] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f, Show g) => Show (a, b, c, d, e, f, g)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g) -> ShowS # show :: (a, b, c, d, e, f, g) -> String # showList :: [(a, b, c, d, e, f, g)] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h) => Show (a, b, c, d, e, f, g, h)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h) -> ShowS # show :: (a, b, c, d, e, f, g, h) -> String # showList :: [(a, b, c, d, e, f, g, h)] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i) => Show (a, b, c, d, e, f, g, h, i)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i) -> ShowS # show :: (a, b, c, d, e, f, g, h, i) -> String # showList :: [(a, b, c, d, e, f, g, h, i)] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j) => Show (a, b, c, d, e, f, g, h, i, j)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j) -> ShowS # show :: (a, b, c, d, e, f, g, h, i, j) -> String # showList :: [(a, b, c, d, e, f, g, h, i, j)] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k) => Show (a, b, c, d, e, f, g, h, i, j, k)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k) -> ShowS # show :: (a, b, c, d, e, f, g, h, i, j, k) -> String # showList :: [(a, b, c, d, e, f, g, h, i, j, k)] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l) => Show (a, b, c, d, e, f, g, h, i, j, k, l)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l) -> ShowS # show :: (a, b, c, d, e, f, g, h, i, j, k, l) -> String # showList :: [(a, b, c, d, e, f, g, h, i, j, k, l)] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> ShowS # show :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> String # showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m)] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m, Show n) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m, n)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> ShowS # show :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> String # showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] -> ShowS #
(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m, Show n, Show o) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> ShowS # show :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> String # showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] -> ShowS #

class Show1 (f :: Type -> Type) #

Lifting of the Show class to unary type constructors.

Since: base-4.9.0.0

Minimal complete definition

liftShowsPrec

Instances

Instances details

Show1 []	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> [a] -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [[a]] -> ShowS #
Show1 Maybe	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Maybe a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Maybe a] -> ShowS #
Show1 Identity	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Identity a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Identity a] -> ShowS #
Show1 Down	Since: base-4.12.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Down a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Down a] -> ShowS #
Show1 NonEmpty	Since: base-4.10.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> NonEmpty a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [NonEmpty a] -> ShowS #
Show1 Set	Since: containers-0.5.9
Instance details Defined in Data.Set.Internal Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Set a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Set a] -> ShowS #
Show a => Show1 (Either a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> Either a a0 -> ShowS # liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [Either a a0] -> ShowS #
Show a => Show1 ((,) a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> (a, a0) -> ShowS # liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [(a, a0)] -> ShowS #
Show1 (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Proxy a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Proxy a] -> ShowS #
Show k => Show1 (Map k)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Map k a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Map k a] -> ShowS #
Show a => Show1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> Const a a0 -> ShowS # liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [Const a a0] -> ShowS #
(Show e, Show1 m) => Show1 (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> ErrorT e m a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [ErrorT e m a] -> ShowS #
(Show1 f, Show1 g) => Show1 (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Product f g a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Product f g a] -> ShowS #
(Show1 f, Show1 g) => Show1 (Sum f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Sum f g a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Sum f g a] -> ShowS #
(Show1 f, Show1 g) => Show1 (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Compose f g a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Compose f g a] -> ShowS #

class Show2 (f :: Type -> Type -> Type) #

Lifting of the Show class to binary type constructors.

Since: base-4.9.0.0

Minimal complete definition

liftShowsPrec2

Instances

Instances details

Show2 Either	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Either a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Either a b] -> ShowS #
Show2 (,)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> (a, b) -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [(a, b)] -> ShowS #
Show2 Map	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Map a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Map a b] -> ShowS #
Show2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Const a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Const a b] -> ShowS #

show :: (Show a, StringConv String b) => a -> b Source #

Read

class Read a #

Parsing of Strings, producing values.

Derived instances of Read make the following assumptions, which derived instances of Show obey:

If the constructor is defined to be an infix operator, then the derived Read instance will parse only infix applications of the constructor (not the prefix form).
Associativity is not used to reduce the occurrence of parentheses, although precedence may be.
If the constructor is defined using record syntax, the derived Read will parse only the record-syntax form, and furthermore, the fields must be given in the same order as the original declaration.
The derived Read instance allows arbitrary Haskell whitespace between tokens of the input string. Extra parentheses are also allowed.

For example, given the declarations

infixr 5 :^:
data Tree a =  Leaf a  |  Tree a :^: Tree a

the derived instance of Read in Haskell 2010 is equivalent to

instance (Read a) => Read (Tree a) where

        readsPrec d r =  readParen (d > app_prec)
                         (\r -> [(Leaf m,t) |
                                 ("Leaf",s) <- lex r,
                                 (m,t) <- readsPrec (app_prec+1) s]) r

                      ++ readParen (d > up_prec)
                         (\r -> [(u:^:v,w) |
                                 (u,s) <- readsPrec (up_prec+1) r,
                                 (":^:",t) <- lex s,
                                 (v,w) <- readsPrec (up_prec+1) t]) r

          where app_prec = 10
                up_prec = 5

Note that right-associativity of :^: is unused.

The derived instance in GHC is equivalent to

instance (Read a) => Read (Tree a) where

        readPrec = parens $ (prec app_prec $ do
                                 Ident "Leaf" <- lexP
                                 m <- step readPrec
                                 return (Leaf m))

                     +++ (prec up_prec $ do
                                 u <- step readPrec
                                 Symbol ":^:" <- lexP
                                 v <- step readPrec
                                 return (u :^: v))

          where app_prec = 10
                up_prec = 5

        readListPrec = readListPrecDefault

Why do both readsPrec and readPrec exist, and why does GHC opt to implement readPrec in derived Read instances instead of readsPrec? The reason is that readsPrec is based on the ReadS type, and although ReadS is mentioned in the Haskell 2010 Report, it is not a very efficient parser data structure.

readPrec, on the other hand, is based on a much more efficient ReadPrec datatype (a.k.a "new-style parsers"), but its definition relies on the use of the RankNTypes language extension. Therefore, readPrec (and its cousin, readListPrec) are marked as GHC-only. Nevertheless, it is recommended to use readPrec instead of readsPrec whenever possible for the efficiency improvements it brings.

As mentioned above, derived Read instances in GHC will implement readPrec instead of readsPrec. The default implementations of readsPrec (and its cousin, readList) will simply use readPrec under the hood. If you are writing a Read instance by hand, it is recommended to write it like so:

instance Read T where
  readPrec     = ...
  readListPrec = readListPrecDefault

Minimal complete definition

readsPrec | readPrec

Instances

Instances details

Read Bool	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Bool # readList :: ReadS [Bool] # readPrec :: ReadPrec Bool # readListPrec :: ReadPrec [Bool] #
Read Char	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Char # readList :: ReadS [Char] # readPrec :: ReadPrec Char # readListPrec :: ReadPrec [Char] #
Read Double	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Double # readList :: ReadS [Double] # readPrec :: ReadPrec Double # readListPrec :: ReadPrec [Double] #
Read Float	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Float # readList :: ReadS [Float] # readPrec :: ReadPrec Float # readListPrec :: ReadPrec [Float] #
Read Int	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Int # readList :: ReadS [Int] # readPrec :: ReadPrec Int # readListPrec :: ReadPrec [Int] #
Read Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods readsPrec :: Int -> ReadS Int8 # readList :: ReadS [Int8] # readPrec :: ReadPrec Int8 # readListPrec :: ReadPrec [Int8] #
Read Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods readsPrec :: Int -> ReadS Int16 # readList :: ReadS [Int16] # readPrec :: ReadPrec Int16 # readListPrec :: ReadPrec [Int16] #
Read Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods readsPrec :: Int -> ReadS Int32 # readList :: ReadS [Int32] # readPrec :: ReadPrec Int32 # readListPrec :: ReadPrec [Int32] #
Read Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods readsPrec :: Int -> ReadS Int64 # readList :: ReadS [Int64] # readPrec :: ReadPrec Int64 # readListPrec :: ReadPrec [Int64] #
Read Integer	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Integer # readList :: ReadS [Integer] # readPrec :: ReadPrec Integer # readListPrec :: ReadPrec [Integer] #
Read Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Natural # readList :: ReadS [Natural] # readPrec :: ReadPrec Natural # readListPrec :: ReadPrec [Natural] #
Read Ordering	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Ordering # readList :: ReadS [Ordering] # readPrec :: ReadPrec Ordering # readListPrec :: ReadPrec [Ordering] #
Read Word	Since: base-4.5.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word # readList :: ReadS [Word] # readPrec :: ReadPrec Word # readListPrec :: ReadPrec [Word] #
Read Word8	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word8 # readList :: ReadS [Word8] # readPrec :: ReadPrec Word8 # readListPrec :: ReadPrec [Word8] #
Read Word16	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word16 # readList :: ReadS [Word16] # readPrec :: ReadPrec Word16 # readListPrec :: ReadPrec [Word16] #
Read Word32	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word32 # readList :: ReadS [Word32] # readPrec :: ReadPrec Word32 # readListPrec :: ReadPrec [Word32] #
Read Word64	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Word64 # readList :: ReadS [Word64] # readPrec :: ReadPrec Word64 # readListPrec :: ReadPrec [Word64] #
Read ()	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS () # readList :: ReadS [()] # readPrec :: ReadPrec () # readListPrec :: ReadPrec [()] #
Read Void	Reading a `Void` value is always a parse error, considering `Void` as a data type with no constructors. Since: base-4.8.0.0
Instance details Defined in Data.Void Methods readsPrec :: Int -> ReadS Void # readList :: ReadS [Void] # readPrec :: ReadPrec Void # readListPrec :: ReadPrec [Void] #
Read ExitCode
Instance details Defined in GHC.IO.Exception Methods readsPrec :: Int -> ReadS ExitCode # readList :: ReadS [ExitCode] # readPrec :: ReadPrec ExitCode # readListPrec :: ReadPrec [ExitCode] #
Read BufferMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS BufferMode # readList :: ReadS [BufferMode] # readPrec :: ReadPrec BufferMode # readListPrec :: ReadPrec [BufferMode] #
Read Newline	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS Newline # readList :: ReadS [Newline] # readPrec :: ReadPrec Newline # readListPrec :: ReadPrec [Newline] #
Read NewlineMode	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS NewlineMode # readList :: ReadS [NewlineMode] # readPrec :: ReadPrec NewlineMode # readListPrec :: ReadPrec [NewlineMode] #
Read All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS All # readList :: ReadS [All] # readPrec :: ReadPrec All # readListPrec :: ReadPrec [All] #
Read Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS Any # readList :: ReadS [Any] # readPrec :: ReadPrec Any # readListPrec :: ReadPrec [Any] #
Read Fixity	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS Fixity # readList :: ReadS [Fixity] # readPrec :: ReadPrec Fixity # readListPrec :: ReadPrec [Fixity] #
Read Associativity	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS Associativity # readList :: ReadS [Associativity] # readPrec :: ReadPrec Associativity # readListPrec :: ReadPrec [Associativity] #
Read SourceUnpackedness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS SourceUnpackedness # readList :: ReadS [SourceUnpackedness] # readPrec :: ReadPrec SourceUnpackedness # readListPrec :: ReadPrec [SourceUnpackedness] #
Read SourceStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS SourceStrictness # readList :: ReadS [SourceStrictness] # readPrec :: ReadPrec SourceStrictness # readListPrec :: ReadPrec [SourceStrictness] #
Read DecidedStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS DecidedStrictness # readList :: ReadS [DecidedStrictness] # readPrec :: ReadPrec DecidedStrictness # readListPrec :: ReadPrec [DecidedStrictness] #
Read Lexeme	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Lexeme # readList :: ReadS [Lexeme] # readPrec :: ReadPrec Lexeme # readListPrec :: ReadPrec [Lexeme] #
Read GeneralCategory	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS GeneralCategory # readList :: ReadS [GeneralCategory] # readPrec :: ReadPrec GeneralCategory # readListPrec :: ReadPrec [GeneralCategory] #
Read ByteString
Instance details Defined in Data.ByteString.Lazy.Internal Methods readsPrec :: Int -> ReadS ByteString # readList :: ReadS [ByteString] # readPrec :: ReadPrec ByteString # readListPrec :: ReadPrec [ByteString] #
Read ByteString
Instance details Defined in Data.ByteString.Internal Methods readsPrec :: Int -> ReadS ByteString # readList :: ReadS [ByteString] # readPrec :: ReadPrec ByteString # readListPrec :: ReadPrec [ByteString] #
Read UUID
Instance details Defined in Data.UUID.Types.Internal Methods readsPrec :: Int -> ReadS UUID # readList :: ReadS [UUID] # readPrec :: ReadPrec UUID # readListPrec :: ReadPrec [UUID] #
Read UnpackedUUID
Instance details Defined in Data.UUID.Types.Internal Methods readsPrec :: Int -> ReadS UnpackedUUID # readList :: ReadS [UnpackedUUID] # readPrec :: ReadPrec UnpackedUUID # readListPrec :: ReadPrec [UnpackedUUID] #
Read a => Read [a]	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS [a] # readList :: ReadS [[a]] # readPrec :: ReadPrec [a] # readListPrec :: ReadPrec [[a]] #
Read a => Read (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (Maybe a) # readList :: ReadS [Maybe a] # readPrec :: ReadPrec (Maybe a) # readListPrec :: ReadPrec [Maybe a] #
(Integral a, Read a) => Read (Ratio a)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (Ratio a) # readList :: ReadS [Ratio a] # readPrec :: ReadPrec (Ratio a) # readListPrec :: ReadPrec [Ratio a] #
Read p => Read (Par1 p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS (Par1 p) # readList :: ReadS [Par1 p] # readPrec :: ReadPrec (Par1 p) # readListPrec :: ReadPrec [Par1 p] #
Read a => Read (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (Min a) # readList :: ReadS [Min a] # readPrec :: ReadPrec (Min a) # readListPrec :: ReadPrec [Min a] #
Read a => Read (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (Max a) # readList :: ReadS [Max a] # readPrec :: ReadPrec (Max a) # readListPrec :: ReadPrec [Max a] #
Read a => Read (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (First a) # readList :: ReadS [First a] # readPrec :: ReadPrec (First a) # readListPrec :: ReadPrec [First a] #
Read a => Read (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (Last a) # readList :: ReadS [Last a] # readPrec :: ReadPrec (Last a) # readListPrec :: ReadPrec [Last a] #
Read m => Read (WrappedMonoid m)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (WrappedMonoid m) # readList :: ReadS [WrappedMonoid m] # readPrec :: ReadPrec (WrappedMonoid m) # readListPrec :: ReadPrec [WrappedMonoid m] #
Read a => Read (Option a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (Option a) # readList :: ReadS [Option a] # readPrec :: ReadPrec (Option a) # readListPrec :: ReadPrec [Option a] #
Read a => Read (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods readsPrec :: Int -> ReadS (ZipList a) # readList :: ReadS [ZipList a] # readPrec :: ReadPrec (ZipList a) # readListPrec :: ReadPrec [ZipList a] #
Read a => Read (Identity a)	This instance would be equivalent to the derived instances of the `Identity` newtype if the `runIdentity` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods readsPrec :: Int -> ReadS (Identity a) # readList :: ReadS [Identity a] # readPrec :: ReadPrec (Identity a) # readListPrec :: ReadPrec [Identity a] #
Read a => Read (First a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods readsPrec :: Int -> ReadS (First a) # readList :: ReadS [First a] # readPrec :: ReadPrec (First a) # readListPrec :: ReadPrec [First a] #
Read a => Read (Last a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods readsPrec :: Int -> ReadS (Last a) # readList :: ReadS [Last a] # readPrec :: ReadPrec (Last a) # readListPrec :: ReadPrec [Last a] #
Read a => Read (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS (Dual a) # readList :: ReadS [Dual a] # readPrec :: ReadPrec (Dual a) # readListPrec :: ReadPrec [Dual a] #
Read a => Read (Sum a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS (Sum a) # readList :: ReadS [Sum a] # readPrec :: ReadPrec (Sum a) # readListPrec :: ReadPrec [Sum a] #
Read a => Read (Product a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS (Product a) # readList :: ReadS [Product a] # readPrec :: ReadPrec (Product a) # readListPrec :: ReadPrec [Product a] #
Read a => Read (Down a)	This instance would be equivalent to the derived instances of the `Down` newtype if the `getDown` field were removed Since: base-4.7.0.0
Instance details Defined in Data.Ord Methods readsPrec :: Int -> ReadS (Down a) # readList :: ReadS [Down a] # readPrec :: ReadPrec (Down a) # readListPrec :: ReadPrec [Down a] #
Read a => Read (NonEmpty a)	Since: base-4.11.0.0
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (NonEmpty a) # readList :: ReadS [NonEmpty a] # readPrec :: ReadPrec (NonEmpty a) # readListPrec :: ReadPrec [NonEmpty a] #
(Read a, Ord a) => Read (Set a)
Instance details Defined in Data.Set.Internal Methods readsPrec :: Int -> ReadS (Set a) # readList :: ReadS [Set a] # readPrec :: ReadPrec (Set a) # readListPrec :: ReadPrec [Set a] #
(Read a, Read b) => Read (Either a b)	Since: base-3.0
Instance details Defined in Data.Either Methods readsPrec :: Int -> ReadS (Either a b) # readList :: ReadS [Either a b] # readPrec :: ReadPrec (Either a b) # readListPrec :: ReadPrec [Either a b] #
Read (V1 p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS (V1 p) # readList :: ReadS [V1 p] # readPrec :: ReadPrec (V1 p) # readListPrec :: ReadPrec [V1 p] #
Read (U1 p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS (U1 p) # readList :: ReadS [U1 p] # readPrec :: ReadPrec (U1 p) # readListPrec :: ReadPrec [U1 p] #
(Read a, Read b) => Read (a, b)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b) # readList :: ReadS [(a, b)] # readPrec :: ReadPrec (a, b) # readListPrec :: ReadPrec [(a, b)] #
(Ix a, Read a, Read b) => Read (Array a b)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (Array a b) # readList :: ReadS [Array a b] # readPrec :: ReadPrec (Array a b) # readListPrec :: ReadPrec [Array a b] #
(Read a, Read b) => Read (Arg a b)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (Arg a b) # readList :: ReadS [Arg a b] # readPrec :: ReadPrec (Arg a b) # readListPrec :: ReadPrec [Arg a b] #
Read (Proxy t)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods readsPrec :: Int -> ReadS (Proxy t) # readList :: ReadS [Proxy t] # readPrec :: ReadPrec (Proxy t) # readListPrec :: ReadPrec [Proxy t] #
(Ord k, Read k, Read e) => Read (Map k e)
Instance details Defined in Data.Map.Internal Methods readsPrec :: Int -> ReadS (Map k e) # readList :: ReadS [Map k e] # readPrec :: ReadPrec (Map k e) # readListPrec :: ReadPrec [Map k e] #
Read (f p) => Read (Rec1 f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS (Rec1 f p) # readList :: ReadS [Rec1 f p] # readPrec :: ReadPrec (Rec1 f p) # readListPrec :: ReadPrec [Rec1 f p] #
(Read a, Read b, Read c) => Read (a, b, c)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c) # readList :: ReadS [(a, b, c)] # readPrec :: ReadPrec (a, b, c) # readListPrec :: ReadPrec [(a, b, c)] #
Read a => Read (Const a b)	This instance would be equivalent to the derived instances of the `Const` newtype if the `getConst` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Const Methods readsPrec :: Int -> ReadS (Const a b) # readList :: ReadS [Const a b] # readPrec :: ReadPrec (Const a b) # readListPrec :: ReadPrec [Const a b] #
Read (f a) => Read (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods readsPrec :: Int -> ReadS (Ap f a) # readList :: ReadS [Ap f a] # readPrec :: ReadPrec (Ap f a) # readListPrec :: ReadPrec [Ap f a] #
Read (f a) => Read (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS (Alt f a) # readList :: ReadS [Alt f a] # readPrec :: ReadPrec (Alt f a) # readListPrec :: ReadPrec [Alt f a] #
(Read e, Read1 m, Read a) => Read (ErrorT e m a)
Instance details Defined in Control.Monad.Trans.Error Methods readsPrec :: Int -> ReadS (ErrorT e m a) # readList :: ReadS [ErrorT e m a] # readPrec :: ReadPrec (ErrorT e m a) # readListPrec :: ReadPrec [ErrorT e m a] #
Read c => Read (K1 i c p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS (K1 i c p) # readList :: ReadS [K1 i c p] # readPrec :: ReadPrec (K1 i c p) # readListPrec :: ReadPrec [K1 i c p] #
(Read (f p), Read (g p)) => Read ((f :+: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS ((f :+: g) p) # readList :: ReadS [(f :+: g) p] # readPrec :: ReadPrec ((f :+: g) p) # readListPrec :: ReadPrec [(f :+: g) p] #
(Read (f p), Read (g p)) => Read ((f :*: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS ((f :: g) p) # readList :: ReadS [(f :: g) p] # readPrec :: ReadPrec ((f :: g) p) # readListPrec :: ReadPrec [(f :: g) p] #
(Read a, Read b, Read c, Read d) => Read (a, b, c, d)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d) # readList :: ReadS [(a, b, c, d)] # readPrec :: ReadPrec (a, b, c, d) # readListPrec :: ReadPrec [(a, b, c, d)] #
(Read1 f, Read1 g, Read a) => Read (Product f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods readsPrec :: Int -> ReadS (Product f g a) # readList :: ReadS [Product f g a] # readPrec :: ReadPrec (Product f g a) # readListPrec :: ReadPrec [Product f g a] #
(Read1 f, Read1 g, Read a) => Read (Sum f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods readsPrec :: Int -> ReadS (Sum f g a) # readList :: ReadS [Sum f g a] # readPrec :: ReadPrec (Sum f g a) # readListPrec :: ReadPrec [Sum f g a] #
Read (f p) => Read (M1 i c f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS (M1 i c f p) # readList :: ReadS [M1 i c f p] # readPrec :: ReadPrec (M1 i c f p) # readListPrec :: ReadPrec [M1 i c f p] #
Read (f (g p)) => Read ((f :.: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods readsPrec :: Int -> ReadS ((f :.: g) p) # readList :: ReadS [(f :.: g) p] # readPrec :: ReadPrec ((f :.: g) p) # readListPrec :: ReadPrec [(f :.: g) p] #
(Read a, Read b, Read c, Read d, Read e) => Read (a, b, c, d, e)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e) # readList :: ReadS [(a, b, c, d, e)] # readPrec :: ReadPrec (a, b, c, d, e) # readListPrec :: ReadPrec [(a, b, c, d, e)] #
(Read1 f, Read1 g, Read a) => Read (Compose f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods readsPrec :: Int -> ReadS (Compose f g a) # readList :: ReadS [Compose f g a] # readPrec :: ReadPrec (Compose f g a) # readListPrec :: ReadPrec [Compose f g a] #
(Read a, Read b, Read c, Read d, Read e, Read f) => Read (a, b, c, d, e, f)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f) # readList :: ReadS [(a, b, c, d, e, f)] # readPrec :: ReadPrec (a, b, c, d, e, f) # readListPrec :: ReadPrec [(a, b, c, d, e, f)] #
(Read a, Read b, Read c, Read d, Read e, Read f, Read g) => Read (a, b, c, d, e, f, g)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g) # readList :: ReadS [(a, b, c, d, e, f, g)] # readPrec :: ReadPrec (a, b, c, d, e, f, g) # readListPrec :: ReadPrec [(a, b, c, d, e, f, g)] #
(Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h) => Read (a, b, c, d, e, f, g, h)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h) # readList :: ReadS [(a, b, c, d, e, f, g, h)] # readPrec :: ReadPrec (a, b, c, d, e, f, g, h) # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h)] #
(Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i) => Read (a, b, c, d, e, f, g, h, i)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i) # readList :: ReadS [(a, b, c, d, e, f, g, h, i)] # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i) # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i)] #
(Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j) => Read (a, b, c, d, e, f, g, h, i, j)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j) # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j)] # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j) # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j)] #
(Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k) => Read (a, b, c, d, e, f, g, h, i, j, k)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k) # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k)] # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k) # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k)] #
(Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l) => Read (a, b, c, d, e, f, g, h, i, j, k, l)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l) # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l)] # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l) # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l)] #
(Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l, m) # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l, m)] # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l, m) # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l, m)] #
(Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m, Read n) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m, n)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] #
(Read a, Read b, Read c, Read d, Read e, Read f, Read g, Read h, Read i, Read j, Read k, Read l, Read m, Read n, Read o) => Read (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # readList :: ReadS [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] # readPrec :: ReadPrec (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # readListPrec :: ReadPrec [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] #

class Read1 (f :: Type -> Type) #

Lifting of the Read class to unary type constructors.

Both liftReadsPrec and liftReadPrec exist to match the interface provided in the Read type class, but it is recommended to implement Read1 instances using liftReadPrec as opposed to liftReadsPrec, since the former is more efficient than the latter. For example:

instance Read1 T where
  liftReadPrec     = ...
  liftReadListPrec = liftReadListPrecDefault

For more information, refer to the documentation for the Read class.

Since: base-4.9.0.0

Minimal complete definition

liftReadsPrec | liftReadPrec

Instances

Instances details

Read1 []	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS [a] # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [[a]] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [a] # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [[a]] #
Read1 Maybe	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Maybe a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Maybe a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Maybe a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Maybe a] #
Read1 Identity	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Identity a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Identity a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Identity a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Identity a] #
Read1 Down	Since: base-4.12.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Down a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Down a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Down a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Down a] #
Read1 NonEmpty	Since: base-4.10.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (NonEmpty a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [NonEmpty a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (NonEmpty a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [NonEmpty a] #
Read a => Read1 (Either a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Either a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Either a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Either a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Either a a0] #
Read a => Read1 ((,) a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (a, a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [(a, a0)] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (a, a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [(a, a0)] #
Read1 (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Proxy a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Proxy a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Proxy a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Proxy a] #
(Ord k, Read k) => Read1 (Map k)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Map k a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Map k a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Map k a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Map k a] #
Read a => Read1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Const a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Const a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Const a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Const a a0] #
(Read e, Read1 m) => Read1 (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (ErrorT e m a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [ErrorT e m a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (ErrorT e m a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [ErrorT e m a] #
(Read1 f, Read1 g) => Read1 (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Product f g a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Product f g a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Product f g a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Product f g a] #
(Read1 f, Read1 g) => Read1 (Sum f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Sum f g a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Sum f g a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Sum f g a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Sum f g a] #
(Read1 f, Read1 g) => Read1 (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Compose f g a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Compose f g a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Compose f g a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Compose f g a] #

class Read2 (f :: Type -> Type -> Type) #

Lifting of the Read class to binary type constructors.

Both liftReadsPrec2 and liftReadPrec2 exist to match the interface provided in the Read type class, but it is recommended to implement Read2 instances using liftReadPrec2 as opposed to liftReadsPrec2, since the former is more efficient than the latter. For example:

instance Read2 T where
  liftReadPrec2     = ...
  liftReadListPrec2 = liftReadListPrec2Default

For more information, refer to the documentation for the Read class. @since 4.9.0.0

Minimal complete definition

liftReadsPrec2 | liftReadPrec2

Instances

Instances details

Read2 Either	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Either a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Either a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Either a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Either a b] #
Read2 (,)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (a, b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [(a, b)] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (a, b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [(a, b)] #
Read2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Const a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Const a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Const a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Const a b] #

readMaybe :: Read a => String -> Maybe a #

Parse a string using the Read instance. Succeeds if there is exactly one valid result.

>>> readMaybe "123" :: Maybe Int
Just 123

>>> readMaybe "hello" :: Maybe Int
Nothing

Since: base-4.6.0.0

Equality and ordering

Eq

class Eq a where #

The Eq class defines equality (==) and inequality (/=). All the basic datatypes exported by the Prelude are instances of Eq, and Eq may be derived for any datatype whose constituents are also instances of Eq.

The Haskell Report defines no laws for Eq. However, == is customarily expected to implement an equivalence relationship where two values comparing equal are indistinguishable by "public" functions, with a "public" function being one not allowing to see implementation details. For example, for a type representing non-normalised natural numbers modulo 100, a "public" function doesn't make the difference between 1 and 201. It is expected to have the following properties:

Reflexivity: x == x = True
Symmetry: x == y = y == x
Transitivity: if x == y && y == z = True, then x == z = True
Substitutivity: if x == y = True and f is a "public" function whose return type is an instance of Eq, then f x == f y = True
Negation: x /= y = not (x == y)

Minimal complete definition: either == or /=.

Minimal complete definition

(==) | (/=)

Methods

(==) :: a -> a -> Bool infix 4 #

(/=) :: a -> a -> Bool infix 4 #

Instances

Instances details

Eq Bool
Instance details Defined in GHC.Classes Methods (==) :: Bool -> Bool -> Bool # (/=) :: Bool -> Bool -> Bool #
Eq Char
Instance details Defined in GHC.Classes Methods (==) :: Char -> Char -> Bool # (/=) :: Char -> Char -> Bool #
Eq Double	Note that due to the presence of `NaN`, `Double`'s `Eq` instance does not satisfy reflexivity. `>>>` `0/0 == (0/0 :: Double)`False Also note that `Double`'s `Eq` instance does not satisfy substitutivity: `>>>` `0 == (-0 :: Double)`True `>>>` `recip 0 == recip (-0 :: Double)`False
Instance details Defined in GHC.Classes Methods (==) :: Double -> Double -> Bool # (/=) :: Double -> Double -> Bool #
Eq Float	Note that due to the presence of `NaN`, `Float`'s `Eq` instance does not satisfy reflexivity. `>>>` `0/0 == (0/0 :: Float)`False Also note that `Float`'s `Eq` instance does not satisfy substitutivity: `>>>` `0 == (-0 :: Float)`True `>>>` `recip 0 == recip (-0 :: Float)`False
Instance details Defined in GHC.Classes Methods (==) :: Float -> Float -> Bool # (/=) :: Float -> Float -> Bool #
Eq Int
Instance details Defined in GHC.Classes Methods (==) :: Int -> Int -> Bool # (/=) :: Int -> Int -> Bool #
Eq Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods (==) :: Int8 -> Int8 -> Bool # (/=) :: Int8 -> Int8 -> Bool #
Eq Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods (==) :: Int16 -> Int16 -> Bool # (/=) :: Int16 -> Int16 -> Bool #
Eq Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods (==) :: Int32 -> Int32 -> Bool # (/=) :: Int32 -> Int32 -> Bool #
Eq Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods (==) :: Int64 -> Int64 -> Bool # (/=) :: Int64 -> Int64 -> Bool #
Eq Integer
Instance details Defined in GHC.Integer.Type Methods (==) :: Integer -> Integer -> Bool # (/=) :: Integer -> Integer -> Bool #
Eq Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Natural Methods (==) :: Natural -> Natural -> Bool # (/=) :: Natural -> Natural -> Bool #
Eq Ordering
Instance details Defined in GHC.Classes Methods (==) :: Ordering -> Ordering -> Bool # (/=) :: Ordering -> Ordering -> Bool #
Eq Word
Instance details Defined in GHC.Classes Methods (==) :: Word -> Word -> Bool # (/=) :: Word -> Word -> Bool #
Eq Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods (==) :: Word8 -> Word8 -> Bool # (/=) :: Word8 -> Word8 -> Bool #
Eq Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods (==) :: Word16 -> Word16 -> Bool # (/=) :: Word16 -> Word16 -> Bool #
Eq Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods (==) :: Word32 -> Word32 -> Bool # (/=) :: Word32 -> Word32 -> Bool #
Eq Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods (==) :: Word64 -> Word64 -> Bool # (/=) :: Word64 -> Word64 -> Bool #
Eq SomeTypeRep
Instance details Defined in Data.Typeable.Internal Methods (==) :: SomeTypeRep -> SomeTypeRep -> Bool # (/=) :: SomeTypeRep -> SomeTypeRep -> Bool #
Eq ()
Instance details Defined in GHC.Classes Methods (==) :: () -> () -> Bool # (/=) :: () -> () -> Bool #
Eq TyCon
Instance details Defined in GHC.Classes Methods (==) :: TyCon -> TyCon -> Bool # (/=) :: TyCon -> TyCon -> Bool #
Eq Module
Instance details Defined in GHC.Classes Methods (==) :: Module -> Module -> Bool # (/=) :: Module -> Module -> Bool #
Eq TrName
Instance details Defined in GHC.Classes Methods (==) :: TrName -> TrName -> Bool # (/=) :: TrName -> TrName -> Bool #
Eq Handle	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: Handle -> Handle -> Bool # (/=) :: Handle -> Handle -> Bool #
Eq Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods (==) :: Void -> Void -> Bool # (/=) :: Void -> Void -> Bool #
Eq SpecConstrAnnotation	Since: base-4.3.0.0
Instance details Defined in GHC.Exts Methods (==) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool # (/=) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool #
Eq ThreadId	Since: base-4.2.0.0
Instance details Defined in GHC.Conc.Sync Methods (==) :: ThreadId -> ThreadId -> Bool # (/=) :: ThreadId -> ThreadId -> Bool #
Eq BlockReason	Since: base-4.3.0.0
Instance details Defined in GHC.Conc.Sync Methods (==) :: BlockReason -> BlockReason -> Bool # (/=) :: BlockReason -> BlockReason -> Bool #
Eq ThreadStatus	Since: base-4.3.0.0
Instance details Defined in GHC.Conc.Sync Methods (==) :: ThreadStatus -> ThreadStatus -> Bool # (/=) :: ThreadStatus -> ThreadStatus -> Bool #
Eq AsyncException	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Exception Methods (==) :: AsyncException -> AsyncException -> Bool # (/=) :: AsyncException -> AsyncException -> Bool #
Eq ArrayException	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Exception Methods (==) :: ArrayException -> ArrayException -> Bool # (/=) :: ArrayException -> ArrayException -> Bool #
Eq ExitCode
Instance details Defined in GHC.IO.Exception Methods (==) :: ExitCode -> ExitCode -> Bool # (/=) :: ExitCode -> ExitCode -> Bool #
Eq IOErrorType	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods (==) :: IOErrorType -> IOErrorType -> Bool # (/=) :: IOErrorType -> IOErrorType -> Bool #
Eq BufferMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: BufferMode -> BufferMode -> Bool # (/=) :: BufferMode -> BufferMode -> Bool #
Eq Newline	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: Newline -> Newline -> Bool # (/=) :: Newline -> Newline -> Bool #
Eq NewlineMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods (==) :: NewlineMode -> NewlineMode -> Bool # (/=) :: NewlineMode -> NewlineMode -> Bool #
Eq MaskingState	Since: base-4.3.0.0
Instance details Defined in GHC.IO Methods (==) :: MaskingState -> MaskingState -> Bool # (/=) :: MaskingState -> MaskingState -> Bool #
Eq IOException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods (==) :: IOException -> IOException -> Bool # (/=) :: IOException -> IOException -> Bool #
Eq ArithException	Since: base-3.0
Instance details Defined in GHC.Exception.Type Methods (==) :: ArithException -> ArithException -> Bool # (/=) :: ArithException -> ArithException -> Bool #
Eq All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods (==) :: All -> All -> Bool # (/=) :: All -> All -> Bool #
Eq Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods (==) :: Any -> Any -> Bool # (/=) :: Any -> Any -> Bool #
Eq Fixity	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Methods (==) :: Fixity -> Fixity -> Bool # (/=) :: Fixity -> Fixity -> Bool #
Eq Associativity	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Methods (==) :: Associativity -> Associativity -> Bool # (/=) :: Associativity -> Associativity -> Bool #
Eq SourceUnpackedness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (/=) :: SourceUnpackedness -> SourceUnpackedness -> Bool #
Eq SourceStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: SourceStrictness -> SourceStrictness -> Bool # (/=) :: SourceStrictness -> SourceStrictness -> Bool #
Eq DecidedStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: DecidedStrictness -> DecidedStrictness -> Bool # (/=) :: DecidedStrictness -> DecidedStrictness -> Bool #
Eq SrcLoc	Since: base-4.9.0.0
Instance details Defined in GHC.Stack.Types Methods (==) :: SrcLoc -> SrcLoc -> Bool # (/=) :: SrcLoc -> SrcLoc -> Bool #
Eq ByteString
Instance details Defined in Data.ByteString.Lazy.Internal Methods (==) :: ByteString -> ByteString -> Bool # (/=) :: ByteString -> ByteString -> Bool #
Eq ByteString
Instance details Defined in Data.ByteString.Internal Methods (==) :: ByteString -> ByteString -> Bool # (/=) :: ByteString -> ByteString -> Bool #
Eq BigNat
Instance details Defined in GHC.Integer.Type Methods (==) :: BigNat -> BigNat -> Bool # (/=) :: BigNat -> BigNat -> Bool #
Eq UnicodeException
Instance details Defined in Data.Text.Encoding.Error Methods (==) :: UnicodeException -> UnicodeException -> Bool # (/=) :: UnicodeException -> UnicodeException -> Bool #
Eq LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods (==) :: LocalTime -> LocalTime -> Bool # (/=) :: LocalTime -> LocalTime -> Bool #
Eq TimeOfDay
Instance details Defined in Data.Time.LocalTime.Internal.TimeOfDay Methods (==) :: TimeOfDay -> TimeOfDay -> Bool # (/=) :: TimeOfDay -> TimeOfDay -> Bool #
Eq UniversalTime
Instance details Defined in Data.Time.Clock.Internal.UniversalTime Methods (==) :: UniversalTime -> UniversalTime -> Bool # (/=) :: UniversalTime -> UniversalTime -> Bool #
Eq UTCTime
Instance details Defined in Data.Time.Clock.Internal.UTCTime Methods (==) :: UTCTime -> UTCTime -> Bool # (/=) :: UTCTime -> UTCTime -> Bool #
Eq NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (==) :: NominalDiffTime -> NominalDiffTime -> Bool # (/=) :: NominalDiffTime -> NominalDiffTime -> Bool #
Eq DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods (==) :: DiffTime -> DiffTime -> Bool # (/=) :: DiffTime -> DiffTime -> Bool #
Eq Day
Instance details Defined in Data.Time.Calendar.Days Methods (==) :: Day -> Day -> Bool # (/=) :: Day -> Day -> Bool #
Eq CodePoint
Instance details Defined in Data.Text.Encoding Methods (==) :: CodePoint -> CodePoint -> Bool # (/=) :: CodePoint -> CodePoint -> Bool #
Eq DecoderState
Instance details Defined in Data.Text.Encoding Methods (==) :: DecoderState -> DecoderState -> Bool # (/=) :: DecoderState -> DecoderState -> Bool #
Eq Leniency Source #
Instance details Defined in Verset.Conv Methods (==) :: Leniency -> Leniency -> Bool # (/=) :: Leniency -> Leniency -> Bool #
Eq UUID
Instance details Defined in Data.UUID.Types.Internal Methods (==) :: UUID -> UUID -> Bool # (/=) :: UUID -> UUID -> Bool #
Eq UnpackedUUID
Instance details Defined in Data.UUID.Types.Internal Methods (==) :: UnpackedUUID -> UnpackedUUID -> Bool # (/=) :: UnpackedUUID -> UnpackedUUID -> Bool #
Eq a => Eq [a]
Instance details Defined in GHC.Classes Methods (==) :: [a] -> [a] -> Bool # (/=) :: [a] -> [a] -> Bool #
Eq a => Eq (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods (==) :: Maybe a -> Maybe a -> Bool # (/=) :: Maybe a -> Maybe a -> Bool #
Eq a => Eq (Ratio a)	Since: base-2.1
Instance details Defined in GHC.Real Methods (==) :: Ratio a -> Ratio a -> Bool # (/=) :: Ratio a -> Ratio a -> Bool #
Eq (Ptr a)	Since: base-2.1
Instance details Defined in GHC.Ptr Methods (==) :: Ptr a -> Ptr a -> Bool # (/=) :: Ptr a -> Ptr a -> Bool #
Eq (FunPtr a)
Instance details Defined in GHC.Ptr Methods (==) :: FunPtr a -> FunPtr a -> Bool # (/=) :: FunPtr a -> FunPtr a -> Bool #
Eq p => Eq (Par1 p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods (==) :: Par1 p -> Par1 p -> Bool # (/=) :: Par1 p -> Par1 p -> Bool #
Eq a => Eq (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: Min a -> Min a -> Bool # (/=) :: Min a -> Min a -> Bool #
Eq a => Eq (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: Max a -> Max a -> Bool # (/=) :: Max a -> Max a -> Bool #
Eq a => Eq (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: First a -> First a -> Bool # (/=) :: First a -> First a -> Bool #
Eq a => Eq (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: Last a -> Last a -> Bool # (/=) :: Last a -> Last a -> Bool #
Eq m => Eq (WrappedMonoid m)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (/=) :: WrappedMonoid m -> WrappedMonoid m -> Bool #
Eq a => Eq (Option a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: Option a -> Option a -> Bool # (/=) :: Option a -> Option a -> Bool #
Eq a => Eq (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods (==) :: ZipList a -> ZipList a -> Bool # (/=) :: ZipList a -> ZipList a -> Bool #
Eq a => Eq (Identity a)	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods (==) :: Identity a -> Identity a -> Bool # (/=) :: Identity a -> Identity a -> Bool #
Eq (TVar a)	Since: base-4.8.0.0
Instance details Defined in GHC.Conc.Sync Methods (==) :: TVar a -> TVar a -> Bool # (/=) :: TVar a -> TVar a -> Bool #
Eq a => Eq (First a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods (==) :: First a -> First a -> Bool # (/=) :: First a -> First a -> Bool #
Eq a => Eq (Last a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods (==) :: Last a -> Last a -> Bool # (/=) :: Last a -> Last a -> Bool #
Eq a => Eq (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods (==) :: Dual a -> Dual a -> Bool # (/=) :: Dual a -> Dual a -> Bool #
Eq a => Eq (Sum a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods (==) :: Sum a -> Sum a -> Bool # (/=) :: Sum a -> Sum a -> Bool #
Eq a => Eq (Product a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods (==) :: Product a -> Product a -> Bool # (/=) :: Product a -> Product a -> Bool #
Eq a => Eq (Down a)	Since: base-4.6.0.0
Instance details Defined in Data.Ord Methods (==) :: Down a -> Down a -> Bool # (/=) :: Down a -> Down a -> Bool #
Eq a => Eq (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (==) :: NonEmpty a -> NonEmpty a -> Bool # (/=) :: NonEmpty a -> NonEmpty a -> Bool #
Eq a => Eq (Set a)
Instance details Defined in Data.Set.Internal Methods (==) :: Set a -> Set a -> Bool # (/=) :: Set a -> Set a -> Bool #
(Eq a, Eq b) => Eq (Either a b)	Since: base-2.1
Instance details Defined in Data.Either Methods (==) :: Either a b -> Either a b -> Bool # (/=) :: Either a b -> Either a b -> Bool #
Eq (V1 p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: V1 p -> V1 p -> Bool # (/=) :: V1 p -> V1 p -> Bool #
Eq (U1 p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: U1 p -> U1 p -> Bool # (/=) :: U1 p -> U1 p -> Bool #
Eq (TypeRep a)	Since: base-2.1
Instance details Defined in Data.Typeable.Internal Methods (==) :: TypeRep a -> TypeRep a -> Bool # (/=) :: TypeRep a -> TypeRep a -> Bool #
(Eq a, Eq b) => Eq (a, b)
Instance details Defined in GHC.Classes Methods (==) :: (a, b) -> (a, b) -> Bool # (/=) :: (a, b) -> (a, b) -> Bool #
Eq a => Eq (Arg a b)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: Arg a b -> Arg a b -> Bool # (/=) :: Arg a b -> Arg a b -> Bool #
Eq (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods (==) :: Proxy s -> Proxy s -> Bool # (/=) :: Proxy s -> Proxy s -> Bool #
(Eq k, Eq a) => Eq (Map k a)
Instance details Defined in Data.Map.Internal Methods (==) :: Map k a -> Map k a -> Bool # (/=) :: Map k a -> Map k a -> Bool #
Eq (f p) => Eq (Rec1 f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods (==) :: Rec1 f p -> Rec1 f p -> Bool # (/=) :: Rec1 f p -> Rec1 f p -> Bool #
Eq (URec (Ptr ()) p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (/=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool #
Eq (URec Char p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: URec Char p -> URec Char p -> Bool # (/=) :: URec Char p -> URec Char p -> Bool #
Eq (URec Double p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: URec Double p -> URec Double p -> Bool # (/=) :: URec Double p -> URec Double p -> Bool #
Eq (URec Float p)
Instance details Defined in GHC.Generics Methods (==) :: URec Float p -> URec Float p -> Bool # (/=) :: URec Float p -> URec Float p -> Bool #
Eq (URec Int p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: URec Int p -> URec Int p -> Bool # (/=) :: URec Int p -> URec Int p -> Bool #
Eq (URec Word p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (==) :: URec Word p -> URec Word p -> Bool # (/=) :: URec Word p -> URec Word p -> Bool #
(Eq a, Eq b, Eq c) => Eq (a, b, c)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c) -> (a, b, c) -> Bool # (/=) :: (a, b, c) -> (a, b, c) -> Bool #
Eq a => Eq (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (==) :: Const a b -> Const a b -> Bool # (/=) :: Const a b -> Const a b -> Bool #
Eq (f a) => Eq (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods (==) :: Ap f a -> Ap f a -> Bool # (/=) :: Ap f a -> Ap f a -> Bool #
Eq (f a) => Eq (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (==) :: Alt f a -> Alt f a -> Bool # (/=) :: Alt f a -> Alt f a -> Bool #
(Eq e, Eq1 m, Eq a) => Eq (ErrorT e m a)
Instance details Defined in Control.Monad.Trans.Error Methods (==) :: ErrorT e m a -> ErrorT e m a -> Bool # (/=) :: ErrorT e m a -> ErrorT e m a -> Bool #
Eq c => Eq (K1 i c p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods (==) :: K1 i c p -> K1 i c p -> Bool # (/=) :: K1 i c p -> K1 i c p -> Bool #
(Eq (f p), Eq (g p)) => Eq ((f :+: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods (==) :: (f :+: g) p -> (f :+: g) p -> Bool # (/=) :: (f :+: g) p -> (f :+: g) p -> Bool #
(Eq (f p), Eq (g p)) => Eq ((f :*: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods (==) :: (f :: g) p -> (f :: g) p -> Bool # (/=) :: (f :: g) p -> (f :: g) p -> Bool #
(Eq a, Eq b, Eq c, Eq d) => Eq (a, b, c, d)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d) -> (a, b, c, d) -> Bool # (/=) :: (a, b, c, d) -> (a, b, c, d) -> Bool #
(Eq1 f, Eq1 g, Eq a) => Eq (Product f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods (==) :: Product f g a -> Product f g a -> Bool # (/=) :: Product f g a -> Product f g a -> Bool #
(Eq1 f, Eq1 g, Eq a) => Eq (Sum f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods (==) :: Sum f g a -> Sum f g a -> Bool # (/=) :: Sum f g a -> Sum f g a -> Bool #
Eq (f p) => Eq (M1 i c f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods (==) :: M1 i c f p -> M1 i c f p -> Bool # (/=) :: M1 i c f p -> M1 i c f p -> Bool #
Eq (f (g p)) => Eq ((f :.: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods (==) :: (f :.: g) p -> (f :.: g) p -> Bool # (/=) :: (f :.: g) p -> (f :.: g) p -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e) => Eq (a, b, c, d, e)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (/=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool #
(Eq1 f, Eq1 g, Eq a) => Eq (Compose f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods (==) :: Compose f g a -> Compose f g a -> Bool # (/=) :: Compose f g a -> Compose f g a -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f) => Eq (a, b, c, d, e, f)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool # (/=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g) => Eq (a, b, c, d, e, f, g)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool # (/=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h) => Eq (a, b, c, d, e, f, g, h)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool # (/=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i) => Eq (a, b, c, d, e, f, g, h, i)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool # (/=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j) => Eq (a, b, c, d, e, f, g, h, i, j)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (/=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k) => Eq (a, b, c, d, e, f, g, h, i, j, k)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (/=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l) => Eq (a, b, c, d, e, f, g, h, i, j, k, l)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (/=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (/=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m, Eq n) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m, n)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (/=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool #
(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m, Eq n, Eq o) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)
Instance details Defined in GHC.Classes Methods (==) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (/=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool #

class Eq1 (f :: Type -> Type) #

Lifting of the Eq class to unary type constructors.

Since: base-4.9.0.0

Minimal complete definition

liftEq

Instances

Instances details

Eq1 []	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> [a] -> [b] -> Bool #
Eq1 Maybe	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> Maybe a -> Maybe b -> Bool #
Eq1 Identity	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> Identity a -> Identity b -> Bool #
Eq1 Down	Since: base-4.12.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> Down a -> Down b -> Bool #
Eq1 NonEmpty	Since: base-4.10.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> NonEmpty a -> NonEmpty b -> Bool #
Eq1 Set	Since: containers-0.5.9
Instance details Defined in Data.Set.Internal Methods liftEq :: (a -> b -> Bool) -> Set a -> Set b -> Bool #
Eq a => Eq1 (Either a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a0 -> b -> Bool) -> Either a a0 -> Either a b -> Bool #
Eq a => Eq1 ((,) a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a0 -> b -> Bool) -> (a, a0) -> (a, b) -> Bool #
Eq1 (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> Proxy a -> Proxy b -> Bool #
Eq k => Eq1 (Map k)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftEq :: (a -> b -> Bool) -> Map k a -> Map k b -> Bool #
Eq a => Eq1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a0 -> b -> Bool) -> Const a a0 -> Const a b -> Bool #
(Eq e, Eq1 m) => Eq1 (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods liftEq :: (a -> b -> Bool) -> ErrorT e m a -> ErrorT e m b -> Bool #
(Eq1 f, Eq1 g) => Eq1 (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods liftEq :: (a -> b -> Bool) -> Product f g a -> Product f g b -> Bool #
(Eq1 f, Eq1 g) => Eq1 (Sum f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods liftEq :: (a -> b -> Bool) -> Sum f g a -> Sum f g b -> Bool #
(Eq1 f, Eq1 g) => Eq1 (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods liftEq :: (a -> b -> Bool) -> Compose f g a -> Compose f g b -> Bool #

class Eq2 (f :: Type -> Type -> Type) #

Lifting of the Eq class to binary type constructors.

Since: base-4.9.0.0

Minimal complete definition

liftEq2

Instances

Instances details

Eq2 Either	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Either a c -> Either b d -> Bool #
Eq2 (,)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> (a, c) -> (b, d) -> Bool #
Eq2 Map	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Map a c -> Map b d -> Bool #
Eq2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Const a c -> Const b d -> Bool #

Ord

class Eq a => Ord a where #

The Ord class is used for totally ordered datatypes.

Instances of Ord can be derived for any user-defined datatype whose constituent types are in Ord. The declared order of the constructors in the data declaration determines the ordering in derived Ord instances. The Ordering datatype allows a single comparison to determine the precise ordering of two objects.

The Haskell Report defines no laws for Ord. However, <= is customarily expected to implement a non-strict partial order and have the following properties:

Transitivity: if x <= y && y <= z = True, then x <= z = True
Reflexivity: x <= x = True
Antisymmetry: if x <= y && y <= x = True, then x == y = True

Note that the following operator interactions are expected to hold:

x >= y = y <= x
x < y = x <= y && x /= y
x > y = y < x
x < y = compare x y == LT
x > y = compare x y == GT
x == y = compare x y == EQ
min x y == if x <= y then x else y = True
max x y == if x >= y then x else y = True

Note that (7.) and (8.) do not require min and max to return either of their arguments. The result is merely required to equal one of the arguments in terms of (==).

Minimal complete definition: either compare or <=. Using compare can be more efficient for complex types.

Minimal complete definition

compare | (<=)

Methods

compare :: a -> a -> Ordering #

(<) :: a -> a -> Bool infix 4 #

(<=) :: a -> a -> Bool infix 4 #

(>) :: a -> a -> Bool infix 4 #

(>=) :: a -> a -> Bool infix 4 #

max :: a -> a -> a #

min :: a -> a -> a #

Instances

Instances details

Ord Bool
Instance details Defined in GHC.Classes Methods compare :: Bool -> Bool -> Ordering # (<) :: Bool -> Bool -> Bool # (<=) :: Bool -> Bool -> Bool # (>) :: Bool -> Bool -> Bool # (>=) :: Bool -> Bool -> Bool # max :: Bool -> Bool -> Bool # min :: Bool -> Bool -> Bool #
Ord Char
Instance details Defined in GHC.Classes Methods compare :: Char -> Char -> Ordering # (<) :: Char -> Char -> Bool # (<=) :: Char -> Char -> Bool # (>) :: Char -> Char -> Bool # (>=) :: Char -> Char -> Bool # max :: Char -> Char -> Char # min :: Char -> Char -> Char #
Ord Double	Note that due to the presence of `NaN`, `Double`'s `Ord` instance does not satisfy reflexivity. `>>>` `0/0 <= (0/0 :: Double)`False Also note that, due to the same, `Ord`'s operator interactions are not respected by `Double`'s instance: `>>>` `(0/0 :: Double) > 1`False `>>>` `compare (0/0 :: Double) 1`GT
Instance details Defined in GHC.Classes Methods compare :: Double -> Double -> Ordering # (<) :: Double -> Double -> Bool # (<=) :: Double -> Double -> Bool # (>) :: Double -> Double -> Bool # (>=) :: Double -> Double -> Bool # max :: Double -> Double -> Double # min :: Double -> Double -> Double #
Ord Float	Note that due to the presence of `NaN`, `Float`'s `Ord` instance does not satisfy reflexivity. `>>>` `0/0 <= (0/0 :: Float)`False Also note that, due to the same, `Ord`'s operator interactions are not respected by `Float`'s instance: `>>>` `(0/0 :: Float) > 1`False `>>>` `compare (0/0 :: Float) 1`GT
Instance details Defined in GHC.Classes Methods compare :: Float -> Float -> Ordering # (<) :: Float -> Float -> Bool # (<=) :: Float -> Float -> Bool # (>) :: Float -> Float -> Bool # (>=) :: Float -> Float -> Bool # max :: Float -> Float -> Float # min :: Float -> Float -> Float #
Ord Int
Instance details Defined in GHC.Classes Methods compare :: Int -> Int -> Ordering # (<) :: Int -> Int -> Bool # (<=) :: Int -> Int -> Bool # (>) :: Int -> Int -> Bool # (>=) :: Int -> Int -> Bool # max :: Int -> Int -> Int # min :: Int -> Int -> Int #
Ord Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods compare :: Int8 -> Int8 -> Ordering # (<) :: Int8 -> Int8 -> Bool # (<=) :: Int8 -> Int8 -> Bool # (>) :: Int8 -> Int8 -> Bool # (>=) :: Int8 -> Int8 -> Bool # max :: Int8 -> Int8 -> Int8 # min :: Int8 -> Int8 -> Int8 #
Ord Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods compare :: Int16 -> Int16 -> Ordering # (<) :: Int16 -> Int16 -> Bool # (<=) :: Int16 -> Int16 -> Bool # (>) :: Int16 -> Int16 -> Bool # (>=) :: Int16 -> Int16 -> Bool # max :: Int16 -> Int16 -> Int16 # min :: Int16 -> Int16 -> Int16 #
Ord Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods compare :: Int32 -> Int32 -> Ordering # (<) :: Int32 -> Int32 -> Bool # (<=) :: Int32 -> Int32 -> Bool # (>) :: Int32 -> Int32 -> Bool # (>=) :: Int32 -> Int32 -> Bool # max :: Int32 -> Int32 -> Int32 # min :: Int32 -> Int32 -> Int32 #
Ord Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods compare :: Int64 -> Int64 -> Ordering # (<) :: Int64 -> Int64 -> Bool # (<=) :: Int64 -> Int64 -> Bool # (>) :: Int64 -> Int64 -> Bool # (>=) :: Int64 -> Int64 -> Bool # max :: Int64 -> Int64 -> Int64 # min :: Int64 -> Int64 -> Int64 #
Ord Integer
Instance details Defined in GHC.Integer.Type Methods compare :: Integer -> Integer -> Ordering # (<) :: Integer -> Integer -> Bool # (<=) :: Integer -> Integer -> Bool # (>) :: Integer -> Integer -> Bool # (>=) :: Integer -> Integer -> Bool # max :: Integer -> Integer -> Integer # min :: Integer -> Integer -> Integer #
Ord Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Natural Methods compare :: Natural -> Natural -> Ordering # (<) :: Natural -> Natural -> Bool # (<=) :: Natural -> Natural -> Bool # (>) :: Natural -> Natural -> Bool # (>=) :: Natural -> Natural -> Bool # max :: Natural -> Natural -> Natural # min :: Natural -> Natural -> Natural #
Ord Ordering
Instance details Defined in GHC.Classes Methods compare :: Ordering -> Ordering -> Ordering # (<) :: Ordering -> Ordering -> Bool # (<=) :: Ordering -> Ordering -> Bool # (>) :: Ordering -> Ordering -> Bool # (>=) :: Ordering -> Ordering -> Bool # max :: Ordering -> Ordering -> Ordering # min :: Ordering -> Ordering -> Ordering #
Ord Word
Instance details Defined in GHC.Classes Methods compare :: Word -> Word -> Ordering # (<) :: Word -> Word -> Bool # (<=) :: Word -> Word -> Bool # (>) :: Word -> Word -> Bool # (>=) :: Word -> Word -> Bool # max :: Word -> Word -> Word # min :: Word -> Word -> Word #
Ord Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods compare :: Word8 -> Word8 -> Ordering # (<) :: Word8 -> Word8 -> Bool # (<=) :: Word8 -> Word8 -> Bool # (>) :: Word8 -> Word8 -> Bool # (>=) :: Word8 -> Word8 -> Bool # max :: Word8 -> Word8 -> Word8 # min :: Word8 -> Word8 -> Word8 #
Ord Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods compare :: Word16 -> Word16 -> Ordering # (<) :: Word16 -> Word16 -> Bool # (<=) :: Word16 -> Word16 -> Bool # (>) :: Word16 -> Word16 -> Bool # (>=) :: Word16 -> Word16 -> Bool # max :: Word16 -> Word16 -> Word16 # min :: Word16 -> Word16 -> Word16 #
Ord Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods compare :: Word32 -> Word32 -> Ordering # (<) :: Word32 -> Word32 -> Bool # (<=) :: Word32 -> Word32 -> Bool # (>) :: Word32 -> Word32 -> Bool # (>=) :: Word32 -> Word32 -> Bool # max :: Word32 -> Word32 -> Word32 # min :: Word32 -> Word32 -> Word32 #
Ord Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods compare :: Word64 -> Word64 -> Ordering # (<) :: Word64 -> Word64 -> Bool # (<=) :: Word64 -> Word64 -> Bool # (>) :: Word64 -> Word64 -> Bool # (>=) :: Word64 -> Word64 -> Bool # max :: Word64 -> Word64 -> Word64 # min :: Word64 -> Word64 -> Word64 #
Ord SomeTypeRep
Instance details Defined in Data.Typeable.Internal Methods compare :: SomeTypeRep -> SomeTypeRep -> Ordering # (<) :: SomeTypeRep -> SomeTypeRep -> Bool # (<=) :: SomeTypeRep -> SomeTypeRep -> Bool # (>) :: SomeTypeRep -> SomeTypeRep -> Bool # (>=) :: SomeTypeRep -> SomeTypeRep -> Bool # max :: SomeTypeRep -> SomeTypeRep -> SomeTypeRep # min :: SomeTypeRep -> SomeTypeRep -> SomeTypeRep #
Ord ()
Instance details Defined in GHC.Classes Methods compare :: () -> () -> Ordering # (<) :: () -> () -> Bool # (<=) :: () -> () -> Bool # (>) :: () -> () -> Bool # (>=) :: () -> () -> Bool # max :: () -> () -> () # min :: () -> () -> () #
Ord TyCon
Instance details Defined in GHC.Classes Methods compare :: TyCon -> TyCon -> Ordering # (<) :: TyCon -> TyCon -> Bool # (<=) :: TyCon -> TyCon -> Bool # (>) :: TyCon -> TyCon -> Bool # (>=) :: TyCon -> TyCon -> Bool # max :: TyCon -> TyCon -> TyCon # min :: TyCon -> TyCon -> TyCon #
Ord Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods compare :: Void -> Void -> Ordering # (<) :: Void -> Void -> Bool # (<=) :: Void -> Void -> Bool # (>) :: Void -> Void -> Bool # (>=) :: Void -> Void -> Bool # max :: Void -> Void -> Void # min :: Void -> Void -> Void #
Ord ThreadId	Since: base-4.2.0.0
Instance details Defined in GHC.Conc.Sync Methods compare :: ThreadId -> ThreadId -> Ordering # (<) :: ThreadId -> ThreadId -> Bool # (<=) :: ThreadId -> ThreadId -> Bool # (>) :: ThreadId -> ThreadId -> Bool # (>=) :: ThreadId -> ThreadId -> Bool # max :: ThreadId -> ThreadId -> ThreadId # min :: ThreadId -> ThreadId -> ThreadId #
Ord BlockReason	Since: base-4.3.0.0
Instance details Defined in GHC.Conc.Sync Methods compare :: BlockReason -> BlockReason -> Ordering # (<) :: BlockReason -> BlockReason -> Bool # (<=) :: BlockReason -> BlockReason -> Bool # (>) :: BlockReason -> BlockReason -> Bool # (>=) :: BlockReason -> BlockReason -> Bool # max :: BlockReason -> BlockReason -> BlockReason # min :: BlockReason -> BlockReason -> BlockReason #
Ord ThreadStatus	Since: base-4.3.0.0
Instance details Defined in GHC.Conc.Sync Methods compare :: ThreadStatus -> ThreadStatus -> Ordering # (<) :: ThreadStatus -> ThreadStatus -> Bool # (<=) :: ThreadStatus -> ThreadStatus -> Bool # (>) :: ThreadStatus -> ThreadStatus -> Bool # (>=) :: ThreadStatus -> ThreadStatus -> Bool # max :: ThreadStatus -> ThreadStatus -> ThreadStatus # min :: ThreadStatus -> ThreadStatus -> ThreadStatus #
Ord AsyncException	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Exception Methods compare :: AsyncException -> AsyncException -> Ordering # (<) :: AsyncException -> AsyncException -> Bool # (<=) :: AsyncException -> AsyncException -> Bool # (>) :: AsyncException -> AsyncException -> Bool # (>=) :: AsyncException -> AsyncException -> Bool # max :: AsyncException -> AsyncException -> AsyncException # min :: AsyncException -> AsyncException -> AsyncException #
Ord ArrayException	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Exception Methods compare :: ArrayException -> ArrayException -> Ordering # (<) :: ArrayException -> ArrayException -> Bool # (<=) :: ArrayException -> ArrayException -> Bool # (>) :: ArrayException -> ArrayException -> Bool # (>=) :: ArrayException -> ArrayException -> Bool # max :: ArrayException -> ArrayException -> ArrayException # min :: ArrayException -> ArrayException -> ArrayException #
Ord ExitCode
Instance details Defined in GHC.IO.Exception Methods compare :: ExitCode -> ExitCode -> Ordering # (<) :: ExitCode -> ExitCode -> Bool # (<=) :: ExitCode -> ExitCode -> Bool # (>) :: ExitCode -> ExitCode -> Bool # (>=) :: ExitCode -> ExitCode -> Bool # max :: ExitCode -> ExitCode -> ExitCode # min :: ExitCode -> ExitCode -> ExitCode #
Ord BufferMode	Since: base-4.2.0.0
Instance details Defined in GHC.IO.Handle.Types Methods compare :: BufferMode -> BufferMode -> Ordering # (<) :: BufferMode -> BufferMode -> Bool # (<=) :: BufferMode -> BufferMode -> Bool # (>) :: BufferMode -> BufferMode -> Bool # (>=) :: BufferMode -> BufferMode -> Bool # max :: BufferMode -> BufferMode -> BufferMode # min :: BufferMode -> BufferMode -> BufferMode #
Ord Newline	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods compare :: Newline -> Newline -> Ordering # (<) :: Newline -> Newline -> Bool # (<=) :: Newline -> Newline -> Bool # (>) :: Newline -> Newline -> Bool # (>=) :: Newline -> Newline -> Bool # max :: Newline -> Newline -> Newline # min :: Newline -> Newline -> Newline #
Ord NewlineMode	Since: base-4.3.0.0
Instance details Defined in GHC.IO.Handle.Types Methods compare :: NewlineMode -> NewlineMode -> Ordering # (<) :: NewlineMode -> NewlineMode -> Bool # (<=) :: NewlineMode -> NewlineMode -> Bool # (>) :: NewlineMode -> NewlineMode -> Bool # (>=) :: NewlineMode -> NewlineMode -> Bool # max :: NewlineMode -> NewlineMode -> NewlineMode # min :: NewlineMode -> NewlineMode -> NewlineMode #
Ord ArithException	Since: base-3.0
Instance details Defined in GHC.Exception.Type Methods compare :: ArithException -> ArithException -> Ordering # (<) :: ArithException -> ArithException -> Bool # (<=) :: ArithException -> ArithException -> Bool # (>) :: ArithException -> ArithException -> Bool # (>=) :: ArithException -> ArithException -> Bool # max :: ArithException -> ArithException -> ArithException # min :: ArithException -> ArithException -> ArithException #
Ord All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods compare :: All -> All -> Ordering # (<) :: All -> All -> Bool # (<=) :: All -> All -> Bool # (>) :: All -> All -> Bool # (>=) :: All -> All -> Bool # max :: All -> All -> All # min :: All -> All -> All #
Ord Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods compare :: Any -> Any -> Ordering # (<) :: Any -> Any -> Bool # (<=) :: Any -> Any -> Bool # (>) :: Any -> Any -> Bool # (>=) :: Any -> Any -> Bool # max :: Any -> Any -> Any # min :: Any -> Any -> Any #
Ord Fixity	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Methods compare :: Fixity -> Fixity -> Ordering # (<) :: Fixity -> Fixity -> Bool # (<=) :: Fixity -> Fixity -> Bool # (>) :: Fixity -> Fixity -> Bool # (>=) :: Fixity -> Fixity -> Bool # max :: Fixity -> Fixity -> Fixity # min :: Fixity -> Fixity -> Fixity #
Ord Associativity	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Methods compare :: Associativity -> Associativity -> Ordering # (<) :: Associativity -> Associativity -> Bool # (<=) :: Associativity -> Associativity -> Bool # (>) :: Associativity -> Associativity -> Bool # (>=) :: Associativity -> Associativity -> Bool # max :: Associativity -> Associativity -> Associativity # min :: Associativity -> Associativity -> Associativity #
Ord SourceUnpackedness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: SourceUnpackedness -> SourceUnpackedness -> Ordering # (<) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (<=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>) :: SourceUnpackedness -> SourceUnpackedness -> Bool # (>=) :: SourceUnpackedness -> SourceUnpackedness -> Bool # max :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness # min :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness #
Ord SourceStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: SourceStrictness -> SourceStrictness -> Ordering # (<) :: SourceStrictness -> SourceStrictness -> Bool # (<=) :: SourceStrictness -> SourceStrictness -> Bool # (>) :: SourceStrictness -> SourceStrictness -> Bool # (>=) :: SourceStrictness -> SourceStrictness -> Bool # max :: SourceStrictness -> SourceStrictness -> SourceStrictness # min :: SourceStrictness -> SourceStrictness -> SourceStrictness #
Ord DecidedStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: DecidedStrictness -> DecidedStrictness -> Ordering # (<) :: DecidedStrictness -> DecidedStrictness -> Bool # (<=) :: DecidedStrictness -> DecidedStrictness -> Bool # (>) :: DecidedStrictness -> DecidedStrictness -> Bool # (>=) :: DecidedStrictness -> DecidedStrictness -> Bool # max :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness # min :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness #
Ord ByteString
Instance details Defined in Data.ByteString.Lazy.Internal Methods compare :: ByteString -> ByteString -> Ordering # (<) :: ByteString -> ByteString -> Bool # (<=) :: ByteString -> ByteString -> Bool # (>) :: ByteString -> ByteString -> Bool # (>=) :: ByteString -> ByteString -> Bool # max :: ByteString -> ByteString -> ByteString # min :: ByteString -> ByteString -> ByteString #
Ord ByteString
Instance details Defined in Data.ByteString.Internal Methods compare :: ByteString -> ByteString -> Ordering # (<) :: ByteString -> ByteString -> Bool # (<=) :: ByteString -> ByteString -> Bool # (>) :: ByteString -> ByteString -> Bool # (>=) :: ByteString -> ByteString -> Bool # max :: ByteString -> ByteString -> ByteString # min :: ByteString -> ByteString -> ByteString #
Ord BigNat
Instance details Defined in GHC.Integer.Type Methods compare :: BigNat -> BigNat -> Ordering # (<) :: BigNat -> BigNat -> Bool # (<=) :: BigNat -> BigNat -> Bool # (>) :: BigNat -> BigNat -> Bool # (>=) :: BigNat -> BigNat -> Bool # max :: BigNat -> BigNat -> BigNat # min :: BigNat -> BigNat -> BigNat #
Ord LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods compare :: LocalTime -> LocalTime -> Ordering # (<) :: LocalTime -> LocalTime -> Bool # (<=) :: LocalTime -> LocalTime -> Bool # (>) :: LocalTime -> LocalTime -> Bool # (>=) :: LocalTime -> LocalTime -> Bool # max :: LocalTime -> LocalTime -> LocalTime # min :: LocalTime -> LocalTime -> LocalTime #
Ord TimeOfDay
Instance details Defined in Data.Time.LocalTime.Internal.TimeOfDay Methods compare :: TimeOfDay -> TimeOfDay -> Ordering # (<) :: TimeOfDay -> TimeOfDay -> Bool # (<=) :: TimeOfDay -> TimeOfDay -> Bool # (>) :: TimeOfDay -> TimeOfDay -> Bool # (>=) :: TimeOfDay -> TimeOfDay -> Bool # max :: TimeOfDay -> TimeOfDay -> TimeOfDay # min :: TimeOfDay -> TimeOfDay -> TimeOfDay #
Ord UniversalTime
Instance details Defined in Data.Time.Clock.Internal.UniversalTime Methods compare :: UniversalTime -> UniversalTime -> Ordering # (<) :: UniversalTime -> UniversalTime -> Bool # (<=) :: UniversalTime -> UniversalTime -> Bool # (>) :: UniversalTime -> UniversalTime -> Bool # (>=) :: UniversalTime -> UniversalTime -> Bool # max :: UniversalTime -> UniversalTime -> UniversalTime # min :: UniversalTime -> UniversalTime -> UniversalTime #
Ord UTCTime
Instance details Defined in Data.Time.Clock.Internal.UTCTime Methods compare :: UTCTime -> UTCTime -> Ordering # (<) :: UTCTime -> UTCTime -> Bool # (<=) :: UTCTime -> UTCTime -> Bool # (>) :: UTCTime -> UTCTime -> Bool # (>=) :: UTCTime -> UTCTime -> Bool # max :: UTCTime -> UTCTime -> UTCTime # min :: UTCTime -> UTCTime -> UTCTime #
Ord NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods compare :: NominalDiffTime -> NominalDiffTime -> Ordering # (<) :: NominalDiffTime -> NominalDiffTime -> Bool # (<=) :: NominalDiffTime -> NominalDiffTime -> Bool # (>) :: NominalDiffTime -> NominalDiffTime -> Bool # (>=) :: NominalDiffTime -> NominalDiffTime -> Bool # max :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # min :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime #
Ord DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods compare :: DiffTime -> DiffTime -> Ordering # (<) :: DiffTime -> DiffTime -> Bool # (<=) :: DiffTime -> DiffTime -> Bool # (>) :: DiffTime -> DiffTime -> Bool # (>=) :: DiffTime -> DiffTime -> Bool # max :: DiffTime -> DiffTime -> DiffTime # min :: DiffTime -> DiffTime -> DiffTime #
Ord Day
Instance details Defined in Data.Time.Calendar.Days Methods compare :: Day -> Day -> Ordering # (<) :: Day -> Day -> Bool # (<=) :: Day -> Day -> Bool # (>) :: Day -> Day -> Bool # (>=) :: Day -> Day -> Bool # max :: Day -> Day -> Day # min :: Day -> Day -> Day #
Ord Leniency Source #
Instance details Defined in Verset.Conv Methods compare :: Leniency -> Leniency -> Ordering # (<) :: Leniency -> Leniency -> Bool # (<=) :: Leniency -> Leniency -> Bool # (>) :: Leniency -> Leniency -> Bool # (>=) :: Leniency -> Leniency -> Bool # max :: Leniency -> Leniency -> Leniency # min :: Leniency -> Leniency -> Leniency #
Ord UUID
Instance details Defined in Data.UUID.Types.Internal Methods compare :: UUID -> UUID -> Ordering # (<) :: UUID -> UUID -> Bool # (<=) :: UUID -> UUID -> Bool # (>) :: UUID -> UUID -> Bool # (>=) :: UUID -> UUID -> Bool # max :: UUID -> UUID -> UUID # min :: UUID -> UUID -> UUID #
Ord UnpackedUUID
Instance details Defined in Data.UUID.Types.Internal Methods compare :: UnpackedUUID -> UnpackedUUID -> Ordering # (<) :: UnpackedUUID -> UnpackedUUID -> Bool # (<=) :: UnpackedUUID -> UnpackedUUID -> Bool # (>) :: UnpackedUUID -> UnpackedUUID -> Bool # (>=) :: UnpackedUUID -> UnpackedUUID -> Bool # max :: UnpackedUUID -> UnpackedUUID -> UnpackedUUID # min :: UnpackedUUID -> UnpackedUUID -> UnpackedUUID #
Ord a => Ord [a]
Instance details Defined in GHC.Classes Methods compare :: [a] -> [a] -> Ordering # (<) :: [a] -> [a] -> Bool # (<=) :: [a] -> [a] -> Bool # (>) :: [a] -> [a] -> Bool # (>=) :: [a] -> [a] -> Bool # max :: [a] -> [a] -> [a] # min :: [a] -> [a] -> [a] #
Ord a => Ord (Maybe a)	Since: base-2.1
Instance details Defined in GHC.Maybe Methods compare :: Maybe a -> Maybe a -> Ordering # (<) :: Maybe a -> Maybe a -> Bool # (<=) :: Maybe a -> Maybe a -> Bool # (>) :: Maybe a -> Maybe a -> Bool # (>=) :: Maybe a -> Maybe a -> Bool # max :: Maybe a -> Maybe a -> Maybe a # min :: Maybe a -> Maybe a -> Maybe a #
Integral a => Ord (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods compare :: Ratio a -> Ratio a -> Ordering # (<) :: Ratio a -> Ratio a -> Bool # (<=) :: Ratio a -> Ratio a -> Bool # (>) :: Ratio a -> Ratio a -> Bool # (>=) :: Ratio a -> Ratio a -> Bool # max :: Ratio a -> Ratio a -> Ratio a # min :: Ratio a -> Ratio a -> Ratio a #
Ord (Ptr a)	Since: base-2.1
Instance details Defined in GHC.Ptr Methods compare :: Ptr a -> Ptr a -> Ordering # (<) :: Ptr a -> Ptr a -> Bool # (<=) :: Ptr a -> Ptr a -> Bool # (>) :: Ptr a -> Ptr a -> Bool # (>=) :: Ptr a -> Ptr a -> Bool # max :: Ptr a -> Ptr a -> Ptr a # min :: Ptr a -> Ptr a -> Ptr a #
Ord (FunPtr a)
Instance details Defined in GHC.Ptr Methods compare :: FunPtr a -> FunPtr a -> Ordering # (<) :: FunPtr a -> FunPtr a -> Bool # (<=) :: FunPtr a -> FunPtr a -> Bool # (>) :: FunPtr a -> FunPtr a -> Bool # (>=) :: FunPtr a -> FunPtr a -> Bool # max :: FunPtr a -> FunPtr a -> FunPtr a # min :: FunPtr a -> FunPtr a -> FunPtr a #
Ord p => Ord (Par1 p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods compare :: Par1 p -> Par1 p -> Ordering # (<) :: Par1 p -> Par1 p -> Bool # (<=) :: Par1 p -> Par1 p -> Bool # (>) :: Par1 p -> Par1 p -> Bool # (>=) :: Par1 p -> Par1 p -> Bool # max :: Par1 p -> Par1 p -> Par1 p # min :: Par1 p -> Par1 p -> Par1 p #
Ord a => Ord (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: Min a -> Min a -> Ordering # (<) :: Min a -> Min a -> Bool # (<=) :: Min a -> Min a -> Bool # (>) :: Min a -> Min a -> Bool # (>=) :: Min a -> Min a -> Bool # max :: Min a -> Min a -> Min a # min :: Min a -> Min a -> Min a #
Ord a => Ord (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: Max a -> Max a -> Ordering # (<) :: Max a -> Max a -> Bool # (<=) :: Max a -> Max a -> Bool # (>) :: Max a -> Max a -> Bool # (>=) :: Max a -> Max a -> Bool # max :: Max a -> Max a -> Max a # min :: Max a -> Max a -> Max a #
Ord a => Ord (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: First a -> First a -> Ordering # (<) :: First a -> First a -> Bool # (<=) :: First a -> First a -> Bool # (>) :: First a -> First a -> Bool # (>=) :: First a -> First a -> Bool # max :: First a -> First a -> First a # min :: First a -> First a -> First a #
Ord a => Ord (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: Last a -> Last a -> Ordering # (<) :: Last a -> Last a -> Bool # (<=) :: Last a -> Last a -> Bool # (>) :: Last a -> Last a -> Bool # (>=) :: Last a -> Last a -> Bool # max :: Last a -> Last a -> Last a # min :: Last a -> Last a -> Last a #
Ord m => Ord (WrappedMonoid m)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: WrappedMonoid m -> WrappedMonoid m -> Ordering # (<) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (<=) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (>) :: WrappedMonoid m -> WrappedMonoid m -> Bool # (>=) :: WrappedMonoid m -> WrappedMonoid m -> Bool # max :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # min :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m #
Ord a => Ord (Option a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: Option a -> Option a -> Ordering # (<) :: Option a -> Option a -> Bool # (<=) :: Option a -> Option a -> Bool # (>) :: Option a -> Option a -> Bool # (>=) :: Option a -> Option a -> Bool # max :: Option a -> Option a -> Option a # min :: Option a -> Option a -> Option a #
Ord a => Ord (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods compare :: ZipList a -> ZipList a -> Ordering # (<) :: ZipList a -> ZipList a -> Bool # (<=) :: ZipList a -> ZipList a -> Bool # (>) :: ZipList a -> ZipList a -> Bool # (>=) :: ZipList a -> ZipList a -> Bool # max :: ZipList a -> ZipList a -> ZipList a # min :: ZipList a -> ZipList a -> ZipList a #
Ord a => Ord (Identity a)	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods compare :: Identity a -> Identity a -> Ordering # (<) :: Identity a -> Identity a -> Bool # (<=) :: Identity a -> Identity a -> Bool # (>) :: Identity a -> Identity a -> Bool # (>=) :: Identity a -> Identity a -> Bool # max :: Identity a -> Identity a -> Identity a # min :: Identity a -> Identity a -> Identity a #
Ord a => Ord (First a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods compare :: First a -> First a -> Ordering # (<) :: First a -> First a -> Bool # (<=) :: First a -> First a -> Bool # (>) :: First a -> First a -> Bool # (>=) :: First a -> First a -> Bool # max :: First a -> First a -> First a # min :: First a -> First a -> First a #
Ord a => Ord (Last a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods compare :: Last a -> Last a -> Ordering # (<) :: Last a -> Last a -> Bool # (<=) :: Last a -> Last a -> Bool # (>) :: Last a -> Last a -> Bool # (>=) :: Last a -> Last a -> Bool # max :: Last a -> Last a -> Last a # min :: Last a -> Last a -> Last a #
Ord a => Ord (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods compare :: Dual a -> Dual a -> Ordering # (<) :: Dual a -> Dual a -> Bool # (<=) :: Dual a -> Dual a -> Bool # (>) :: Dual a -> Dual a -> Bool # (>=) :: Dual a -> Dual a -> Bool # max :: Dual a -> Dual a -> Dual a # min :: Dual a -> Dual a -> Dual a #
Ord a => Ord (Sum a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods compare :: Sum a -> Sum a -> Ordering # (<) :: Sum a -> Sum a -> Bool # (<=) :: Sum a -> Sum a -> Bool # (>) :: Sum a -> Sum a -> Bool # (>=) :: Sum a -> Sum a -> Bool # max :: Sum a -> Sum a -> Sum a # min :: Sum a -> Sum a -> Sum a #
Ord a => Ord (Product a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods compare :: Product a -> Product a -> Ordering # (<) :: Product a -> Product a -> Bool # (<=) :: Product a -> Product a -> Bool # (>) :: Product a -> Product a -> Bool # (>=) :: Product a -> Product a -> Bool # max :: Product a -> Product a -> Product a # min :: Product a -> Product a -> Product a #
Ord a => Ord (Down a)	Since: base-4.6.0.0
Instance details Defined in Data.Ord Methods compare :: Down a -> Down a -> Ordering # (<) :: Down a -> Down a -> Bool # (<=) :: Down a -> Down a -> Bool # (>) :: Down a -> Down a -> Bool # (>=) :: Down a -> Down a -> Bool # max :: Down a -> Down a -> Down a # min :: Down a -> Down a -> Down a #
Ord a => Ord (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods compare :: NonEmpty a -> NonEmpty a -> Ordering # (<) :: NonEmpty a -> NonEmpty a -> Bool # (<=) :: NonEmpty a -> NonEmpty a -> Bool # (>) :: NonEmpty a -> NonEmpty a -> Bool # (>=) :: NonEmpty a -> NonEmpty a -> Bool # max :: NonEmpty a -> NonEmpty a -> NonEmpty a # min :: NonEmpty a -> NonEmpty a -> NonEmpty a #
Ord a => Ord (Set a)
Instance details Defined in Data.Set.Internal Methods compare :: Set a -> Set a -> Ordering # (<) :: Set a -> Set a -> Bool # (<=) :: Set a -> Set a -> Bool # (>) :: Set a -> Set a -> Bool # (>=) :: Set a -> Set a -> Bool # max :: Set a -> Set a -> Set a # min :: Set a -> Set a -> Set a #
(Ord a, Ord b) => Ord (Either a b)	Since: base-2.1
Instance details Defined in Data.Either Methods compare :: Either a b -> Either a b -> Ordering # (<) :: Either a b -> Either a b -> Bool # (<=) :: Either a b -> Either a b -> Bool # (>) :: Either a b -> Either a b -> Bool # (>=) :: Either a b -> Either a b -> Bool # max :: Either a b -> Either a b -> Either a b # min :: Either a b -> Either a b -> Either a b #
Ord (V1 p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: V1 p -> V1 p -> Ordering # (<) :: V1 p -> V1 p -> Bool # (<=) :: V1 p -> V1 p -> Bool # (>) :: V1 p -> V1 p -> Bool # (>=) :: V1 p -> V1 p -> Bool # max :: V1 p -> V1 p -> V1 p # min :: V1 p -> V1 p -> V1 p #
Ord (U1 p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods compare :: U1 p -> U1 p -> Ordering # (<) :: U1 p -> U1 p -> Bool # (<=) :: U1 p -> U1 p -> Bool # (>) :: U1 p -> U1 p -> Bool # (>=) :: U1 p -> U1 p -> Bool # max :: U1 p -> U1 p -> U1 p # min :: U1 p -> U1 p -> U1 p #
Ord (TypeRep a)	Since: base-4.4.0.0
Instance details Defined in Data.Typeable.Internal Methods compare :: TypeRep a -> TypeRep a -> Ordering # (<) :: TypeRep a -> TypeRep a -> Bool # (<=) :: TypeRep a -> TypeRep a -> Bool # (>) :: TypeRep a -> TypeRep a -> Bool # (>=) :: TypeRep a -> TypeRep a -> Bool # max :: TypeRep a -> TypeRep a -> TypeRep a # min :: TypeRep a -> TypeRep a -> TypeRep a #
(Ord a, Ord b) => Ord (a, b)
Instance details Defined in GHC.Classes Methods compare :: (a, b) -> (a, b) -> Ordering # (<) :: (a, b) -> (a, b) -> Bool # (<=) :: (a, b) -> (a, b) -> Bool # (>) :: (a, b) -> (a, b) -> Bool # (>=) :: (a, b) -> (a, b) -> Bool # max :: (a, b) -> (a, b) -> (a, b) # min :: (a, b) -> (a, b) -> (a, b) #
Ord a => Ord (Arg a b)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: Arg a b -> Arg a b -> Ordering # (<) :: Arg a b -> Arg a b -> Bool # (<=) :: Arg a b -> Arg a b -> Bool # (>) :: Arg a b -> Arg a b -> Bool # (>=) :: Arg a b -> Arg a b -> Bool # max :: Arg a b -> Arg a b -> Arg a b # min :: Arg a b -> Arg a b -> Arg a b #
Ord (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods compare :: Proxy s -> Proxy s -> Ordering # (<) :: Proxy s -> Proxy s -> Bool # (<=) :: Proxy s -> Proxy s -> Bool # (>) :: Proxy s -> Proxy s -> Bool # (>=) :: Proxy s -> Proxy s -> Bool # max :: Proxy s -> Proxy s -> Proxy s # min :: Proxy s -> Proxy s -> Proxy s #
(Ord k, Ord v) => Ord (Map k v)
Instance details Defined in Data.Map.Internal Methods compare :: Map k v -> Map k v -> Ordering # (<) :: Map k v -> Map k v -> Bool # (<=) :: Map k v -> Map k v -> Bool # (>) :: Map k v -> Map k v -> Bool # (>=) :: Map k v -> Map k v -> Bool # max :: Map k v -> Map k v -> Map k v # min :: Map k v -> Map k v -> Map k v #
Ord (f p) => Ord (Rec1 f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods compare :: Rec1 f p -> Rec1 f p -> Ordering # (<) :: Rec1 f p -> Rec1 f p -> Bool # (<=) :: Rec1 f p -> Rec1 f p -> Bool # (>) :: Rec1 f p -> Rec1 f p -> Bool # (>=) :: Rec1 f p -> Rec1 f p -> Bool # max :: Rec1 f p -> Rec1 f p -> Rec1 f p # min :: Rec1 f p -> Rec1 f p -> Rec1 f p #
Ord (URec (Ptr ()) p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: URec (Ptr ()) p -> URec (Ptr ()) p -> Ordering # (<) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (<=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (>) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # (>=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool # max :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p # min :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p #
Ord (URec Char p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: URec Char p -> URec Char p -> Ordering # (<) :: URec Char p -> URec Char p -> Bool # (<=) :: URec Char p -> URec Char p -> Bool # (>) :: URec Char p -> URec Char p -> Bool # (>=) :: URec Char p -> URec Char p -> Bool # max :: URec Char p -> URec Char p -> URec Char p # min :: URec Char p -> URec Char p -> URec Char p #
Ord (URec Double p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: URec Double p -> URec Double p -> Ordering # (<) :: URec Double p -> URec Double p -> Bool # (<=) :: URec Double p -> URec Double p -> Bool # (>) :: URec Double p -> URec Double p -> Bool # (>=) :: URec Double p -> URec Double p -> Bool # max :: URec Double p -> URec Double p -> URec Double p # min :: URec Double p -> URec Double p -> URec Double p #
Ord (URec Float p)
Instance details Defined in GHC.Generics Methods compare :: URec Float p -> URec Float p -> Ordering # (<) :: URec Float p -> URec Float p -> Bool # (<=) :: URec Float p -> URec Float p -> Bool # (>) :: URec Float p -> URec Float p -> Bool # (>=) :: URec Float p -> URec Float p -> Bool # max :: URec Float p -> URec Float p -> URec Float p # min :: URec Float p -> URec Float p -> URec Float p #
Ord (URec Int p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: URec Int p -> URec Int p -> Ordering # (<) :: URec Int p -> URec Int p -> Bool # (<=) :: URec Int p -> URec Int p -> Bool # (>) :: URec Int p -> URec Int p -> Bool # (>=) :: URec Int p -> URec Int p -> Bool # max :: URec Int p -> URec Int p -> URec Int p # min :: URec Int p -> URec Int p -> URec Int p #
Ord (URec Word p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods compare :: URec Word p -> URec Word p -> Ordering # (<) :: URec Word p -> URec Word p -> Bool # (<=) :: URec Word p -> URec Word p -> Bool # (>) :: URec Word p -> URec Word p -> Bool # (>=) :: URec Word p -> URec Word p -> Bool # max :: URec Word p -> URec Word p -> URec Word p # min :: URec Word p -> URec Word p -> URec Word p #
(Ord a, Ord b, Ord c) => Ord (a, b, c)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c) -> (a, b, c) -> Ordering # (<) :: (a, b, c) -> (a, b, c) -> Bool # (<=) :: (a, b, c) -> (a, b, c) -> Bool # (>) :: (a, b, c) -> (a, b, c) -> Bool # (>=) :: (a, b, c) -> (a, b, c) -> Bool # max :: (a, b, c) -> (a, b, c) -> (a, b, c) # min :: (a, b, c) -> (a, b, c) -> (a, b, c) #
Ord a => Ord (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods compare :: Const a b -> Const a b -> Ordering # (<) :: Const a b -> Const a b -> Bool # (<=) :: Const a b -> Const a b -> Bool # (>) :: Const a b -> Const a b -> Bool # (>=) :: Const a b -> Const a b -> Bool # max :: Const a b -> Const a b -> Const a b # min :: Const a b -> Const a b -> Const a b #
Ord (f a) => Ord (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods compare :: Ap f a -> Ap f a -> Ordering # (<) :: Ap f a -> Ap f a -> Bool # (<=) :: Ap f a -> Ap f a -> Bool # (>) :: Ap f a -> Ap f a -> Bool # (>=) :: Ap f a -> Ap f a -> Bool # max :: Ap f a -> Ap f a -> Ap f a # min :: Ap f a -> Ap f a -> Ap f a #
Ord (f a) => Ord (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods compare :: Alt f a -> Alt f a -> Ordering # (<) :: Alt f a -> Alt f a -> Bool # (<=) :: Alt f a -> Alt f a -> Bool # (>) :: Alt f a -> Alt f a -> Bool # (>=) :: Alt f a -> Alt f a -> Bool # max :: Alt f a -> Alt f a -> Alt f a # min :: Alt f a -> Alt f a -> Alt f a #
(Ord e, Ord1 m, Ord a) => Ord (ErrorT e m a)
Instance details Defined in Control.Monad.Trans.Error Methods compare :: ErrorT e m a -> ErrorT e m a -> Ordering # (<) :: ErrorT e m a -> ErrorT e m a -> Bool # (<=) :: ErrorT e m a -> ErrorT e m a -> Bool # (>) :: ErrorT e m a -> ErrorT e m a -> Bool # (>=) :: ErrorT e m a -> ErrorT e m a -> Bool # max :: ErrorT e m a -> ErrorT e m a -> ErrorT e m a # min :: ErrorT e m a -> ErrorT e m a -> ErrorT e m a #
Ord c => Ord (K1 i c p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods compare :: K1 i c p -> K1 i c p -> Ordering # (<) :: K1 i c p -> K1 i c p -> Bool # (<=) :: K1 i c p -> K1 i c p -> Bool # (>) :: K1 i c p -> K1 i c p -> Bool # (>=) :: K1 i c p -> K1 i c p -> Bool # max :: K1 i c p -> K1 i c p -> K1 i c p # min :: K1 i c p -> K1 i c p -> K1 i c p #
(Ord (f p), Ord (g p)) => Ord ((f :+: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods compare :: (f :+: g) p -> (f :+: g) p -> Ordering # (<) :: (f :+: g) p -> (f :+: g) p -> Bool # (<=) :: (f :+: g) p -> (f :+: g) p -> Bool # (>) :: (f :+: g) p -> (f :+: g) p -> Bool # (>=) :: (f :+: g) p -> (f :+: g) p -> Bool # max :: (f :+: g) p -> (f :+: g) p -> (f :+: g) p # min :: (f :+: g) p -> (f :+: g) p -> (f :+: g) p #
(Ord (f p), Ord (g p)) => Ord ((f :*: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods compare :: (f :: g) p -> (f :: g) p -> Ordering # (<) :: (f :: g) p -> (f :: g) p -> Bool # (<=) :: (f :: g) p -> (f :: g) p -> Bool # (>) :: (f :: g) p -> (f :: g) p -> Bool # (>=) :: (f :: g) p -> (f :: g) p -> Bool # max :: (f :: g) p -> (f :: g) p -> (f :: g) p # min :: (f :: g) p -> (f :: g) p -> (f :: g) p #
(Ord a, Ord b, Ord c, Ord d) => Ord (a, b, c, d)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d) -> (a, b, c, d) -> Ordering # (<) :: (a, b, c, d) -> (a, b, c, d) -> Bool # (<=) :: (a, b, c, d) -> (a, b, c, d) -> Bool # (>) :: (a, b, c, d) -> (a, b, c, d) -> Bool # (>=) :: (a, b, c, d) -> (a, b, c, d) -> Bool # max :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d) # min :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d) #
(Ord1 f, Ord1 g, Ord a) => Ord (Product f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods compare :: Product f g a -> Product f g a -> Ordering # (<) :: Product f g a -> Product f g a -> Bool # (<=) :: Product f g a -> Product f g a -> Bool # (>) :: Product f g a -> Product f g a -> Bool # (>=) :: Product f g a -> Product f g a -> Bool # max :: Product f g a -> Product f g a -> Product f g a # min :: Product f g a -> Product f g a -> Product f g a #
(Ord1 f, Ord1 g, Ord a) => Ord (Sum f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods compare :: Sum f g a -> Sum f g a -> Ordering # (<) :: Sum f g a -> Sum f g a -> Bool # (<=) :: Sum f g a -> Sum f g a -> Bool # (>) :: Sum f g a -> Sum f g a -> Bool # (>=) :: Sum f g a -> Sum f g a -> Bool # max :: Sum f g a -> Sum f g a -> Sum f g a # min :: Sum f g a -> Sum f g a -> Sum f g a #
Ord (f p) => Ord (M1 i c f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods compare :: M1 i c f p -> M1 i c f p -> Ordering # (<) :: M1 i c f p -> M1 i c f p -> Bool # (<=) :: M1 i c f p -> M1 i c f p -> Bool # (>) :: M1 i c f p -> M1 i c f p -> Bool # (>=) :: M1 i c f p -> M1 i c f p -> Bool # max :: M1 i c f p -> M1 i c f p -> M1 i c f p # min :: M1 i c f p -> M1 i c f p -> M1 i c f p #
Ord (f (g p)) => Ord ((f :.: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Methods compare :: (f :.: g) p -> (f :.: g) p -> Ordering # (<) :: (f :.: g) p -> (f :.: g) p -> Bool # (<=) :: (f :.: g) p -> (f :.: g) p -> Bool # (>) :: (f :.: g) p -> (f :.: g) p -> Bool # (>=) :: (f :.: g) p -> (f :.: g) p -> Bool # max :: (f :.: g) p -> (f :.: g) p -> (f :.: g) p # min :: (f :.: g) p -> (f :.: g) p -> (f :.: g) p #
(Ord a, Ord b, Ord c, Ord d, Ord e) => Ord (a, b, c, d, e)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e) -> (a, b, c, d, e) -> Ordering # (<) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (<=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (>) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # (>=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool # max :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) # min :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) #
(Ord1 f, Ord1 g, Ord a) => Ord (Compose f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods compare :: Compose f g a -> Compose f g a -> Ordering # (<) :: Compose f g a -> Compose f g a -> Bool # (<=) :: Compose f g a -> Compose f g a -> Bool # (>) :: Compose f g a -> Compose f g a -> Bool # (>=) :: Compose f g a -> Compose f g a -> Bool # max :: Compose f g a -> Compose f g a -> Compose f g a # min :: Compose f g a -> Compose f g a -> Compose f g a #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f) => Ord (a, b, c, d, e, f)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Ordering # (<) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool # (<=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool # (>) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool # (>=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool # max :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> (a, b, c, d, e, f) # min :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> (a, b, c, d, e, f) #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g) => Ord (a, b, c, d, e, f, g)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Ordering # (<) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool # (<=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool # (>) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool # (>=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool # max :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) # min :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h) => Ord (a, b, c, d, e, f, g, h)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Ordering # (<) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool # (<=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool # (>) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool # (>=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool # max :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) # min :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i) => Ord (a, b, c, d, e, f, g, h, i)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool # max :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) # min :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j) => Ord (a, b, c, d, e, f, g, h, i, j)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) # min :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k) => Ord (a, b, c, d, e, f, g, h, i, j, k)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) # min :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l) => Ord (a, b, c, d, e, f, g, h, i, j, k, l)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) # min :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) # min :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m, n)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # min :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) #
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n, Ord o) => Ord (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)
Instance details Defined in GHC.Classes Methods compare :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Ordering # (<) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (<=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (>) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # (>=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool # max :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # min :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) #

class Eq1 f => Ord1 (f :: Type -> Type) #

Lifting of the Ord class to unary type constructors.

Since: base-4.9.0.0

Minimal complete definition

liftCompare

Instances

Instances details

Ord1 []	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> [a] -> [b] -> Ordering #
Ord1 Maybe	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> Maybe a -> Maybe b -> Ordering #
Ord1 Identity	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> Identity a -> Identity b -> Ordering #
Ord1 Down	Since: base-4.12.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> Down a -> Down b -> Ordering #
Ord1 NonEmpty	Since: base-4.10.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> NonEmpty a -> NonEmpty b -> Ordering #
Ord1 Set	Since: containers-0.5.9
Instance details Defined in Data.Set.Internal Methods liftCompare :: (a -> b -> Ordering) -> Set a -> Set b -> Ordering #
Ord a => Ord1 (Either a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a0 -> b -> Ordering) -> Either a a0 -> Either a b -> Ordering #
Ord a => Ord1 ((,) a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a0 -> b -> Ordering) -> (a, a0) -> (a, b) -> Ordering #
Ord1 (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> Proxy a -> Proxy b -> Ordering #
Ord k => Ord1 (Map k)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftCompare :: (a -> b -> Ordering) -> Map k a -> Map k b -> Ordering #
Ord a => Ord1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a0 -> b -> Ordering) -> Const a a0 -> Const a b -> Ordering #
(Ord e, Ord1 m) => Ord1 (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods liftCompare :: (a -> b -> Ordering) -> ErrorT e m a -> ErrorT e m b -> Ordering #
(Ord1 f, Ord1 g) => Ord1 (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods liftCompare :: (a -> b -> Ordering) -> Product f g a -> Product f g b -> Ordering #
(Ord1 f, Ord1 g) => Ord1 (Sum f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods liftCompare :: (a -> b -> Ordering) -> Sum f g a -> Sum f g b -> Ordering #
(Ord1 f, Ord1 g) => Ord1 (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods liftCompare :: (a -> b -> Ordering) -> Compose f g a -> Compose f g b -> Ordering #

class Eq2 f => Ord2 (f :: Type -> Type -> Type) #

Lifting of the Ord class to binary type constructors.

Since: base-4.9.0.0

Minimal complete definition

liftCompare2

Instances

Instances details

Ord2 Either	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Either a c -> Either b d -> Ordering #
Ord2 (,)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> (a, c) -> (b, d) -> Ordering #
Ord2 Map	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Map a c -> Map b d -> Ordering #
Ord2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Const a c -> Const b d -> Ordering #

data Ordering #

Constructors

LT
EQ
GT

Instances

Instances details

Bounded Ordering	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Ordering # maxBound :: Ordering #
Enum Ordering	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Ordering -> Ordering # pred :: Ordering -> Ordering # toEnum :: Int -> Ordering # fromEnum :: Ordering -> Int # enumFrom :: Ordering -> [Ordering] # enumFromThen :: Ordering -> Ordering -> [Ordering] # enumFromTo :: Ordering -> Ordering -> [Ordering] # enumFromThenTo :: Ordering -> Ordering -> Ordering -> [Ordering] #
Eq Ordering
Instance details Defined in GHC.Classes Methods (==) :: Ordering -> Ordering -> Bool # (/=) :: Ordering -> Ordering -> Bool #
Ord Ordering
Instance details Defined in GHC.Classes Methods compare :: Ordering -> Ordering -> Ordering # (<) :: Ordering -> Ordering -> Bool # (<=) :: Ordering -> Ordering -> Bool # (>) :: Ordering -> Ordering -> Bool # (>=) :: Ordering -> Ordering -> Bool # max :: Ordering -> Ordering -> Ordering # min :: Ordering -> Ordering -> Ordering #
Read Ordering	Since: base-2.1
Instance details Defined in GHC.Read Methods readsPrec :: Int -> ReadS Ordering # readList :: ReadS [Ordering] # readPrec :: ReadPrec Ordering # readListPrec :: ReadPrec [Ordering] #
Show Ordering	Since: base-2.1
Instance details Defined in GHC.Show Methods showsPrec :: Int -> Ordering -> ShowS # show :: Ordering -> String # showList :: [Ordering] -> ShowS #
Generic Ordering	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep Ordering :: Type -> Type # Methods from :: Ordering -> Rep Ordering x # to :: Rep Ordering x -> Ordering #
Semigroup Ordering	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: Ordering -> Ordering -> Ordering # sconcat :: NonEmpty Ordering -> Ordering # stimes :: Integral b => b -> Ordering -> Ordering #
Monoid Ordering	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: Ordering # mappend :: Ordering -> Ordering -> Ordering # mconcat :: [Ordering] -> Ordering #
type Rep Ordering
Instance details Defined in GHC.Generics type Rep Ordering = D1 ('MetaData "Ordering" "GHC.Types" "ghc-prim" 'False) (C1 ('MetaCons "LT" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "EQ" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "GT" 'PrefixI 'False) (U1 :: Type -> Type)))

newtype Down a #

The Down type allows you to reverse sort order conveniently. A value of type Down a contains a value of type a (represented as Down a). If a has an Ord instance associated with it then comparing two values thus wrapped will give you the opposite of their normal sort order. This is particularly useful when sorting in generalised list comprehensions, as in: then sortWith by Down x

Since: base-4.6.0.0

Constructors

Down a

Instances

Instances details

Monad Down	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods (>>=) :: Down a -> (a -> Down b) -> Down b # (>>) :: Down a -> Down b -> Down b # return :: a -> Down a #
Functor Down	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods fmap :: (a -> b) -> Down a -> Down b # (<$) :: a -> Down b -> Down a #
MonadFix Down	Since: base-4.12.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Down a) -> Down a #
Applicative Down	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods pure :: a -> Down a # (<>) :: Down (a -> b) -> Down a -> Down b # liftA2 :: (a -> b -> c) -> Down a -> Down b -> Down c # (>) :: Down a -> Down b -> Down b # (<*) :: Down a -> Down b -> Down a #
Foldable Down	Since: base-4.12.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Down m -> m # foldMap :: Monoid m => (a -> m) -> Down a -> m # foldMap' :: Monoid m => (a -> m) -> Down a -> m # foldr :: (a -> b -> b) -> b -> Down a -> b # foldr' :: (a -> b -> b) -> b -> Down a -> b # foldl :: (b -> a -> b) -> b -> Down a -> b # foldl' :: (b -> a -> b) -> b -> Down a -> b # foldr1 :: (a -> a -> a) -> Down a -> a # foldl1 :: (a -> a -> a) -> Down a -> a # toList :: Down a -> [a] # null :: Down a -> Bool # length :: Down a -> Int # elem :: Eq a => a -> Down a -> Bool # maximum :: Ord a => Down a -> a # minimum :: Ord a => Down a -> a # sum :: Num a => Down a -> a # product :: Num a => Down a -> a #
Traversable Down	Since: base-4.12.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Down a -> f (Down b) # sequenceA :: Applicative f => Down (f a) -> f (Down a) # mapM :: Monad m => (a -> m b) -> Down a -> m (Down b) # sequence :: Monad m => Down (m a) -> m (Down a) #
Eq1 Down	Since: base-4.12.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> Down a -> Down b -> Bool #
Ord1 Down	Since: base-4.12.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> Down a -> Down b -> Ordering #
Read1 Down	Since: base-4.12.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Down a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Down a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Down a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Down a] #
Show1 Down	Since: base-4.12.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Down a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Down a] -> ShowS #
Bounded a => Bounded (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods minBound :: Down a # maxBound :: Down a #
Enum a => Enum (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods succ :: Down a -> Down a # pred :: Down a -> Down a # toEnum :: Int -> Down a # fromEnum :: Down a -> Int # enumFrom :: Down a -> [Down a] # enumFromThen :: Down a -> Down a -> [Down a] # enumFromTo :: Down a -> Down a -> [Down a] # enumFromThenTo :: Down a -> Down a -> Down a -> [Down a] #
Eq a => Eq (Down a)	Since: base-4.6.0.0
Instance details Defined in Data.Ord Methods (==) :: Down a -> Down a -> Bool # (/=) :: Down a -> Down a -> Bool #
Floating a => Floating (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods pi :: Down a # exp :: Down a -> Down a # log :: Down a -> Down a # sqrt :: Down a -> Down a # (**) :: Down a -> Down a -> Down a # logBase :: Down a -> Down a -> Down a # sin :: Down a -> Down a # cos :: Down a -> Down a # tan :: Down a -> Down a # asin :: Down a -> Down a # acos :: Down a -> Down a # atan :: Down a -> Down a # sinh :: Down a -> Down a # cosh :: Down a -> Down a # tanh :: Down a -> Down a # asinh :: Down a -> Down a # acosh :: Down a -> Down a # atanh :: Down a -> Down a # log1p :: Down a -> Down a # expm1 :: Down a -> Down a # log1pexp :: Down a -> Down a # log1mexp :: Down a -> Down a #
Fractional a => Fractional (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods (/) :: Down a -> Down a -> Down a # recip :: Down a -> Down a # fromRational :: Rational -> Down a #
Integral a => Integral (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods quot :: Down a -> Down a -> Down a # rem :: Down a -> Down a -> Down a # div :: Down a -> Down a -> Down a # mod :: Down a -> Down a -> Down a # quotRem :: Down a -> Down a -> (Down a, Down a) # divMod :: Down a -> Down a -> (Down a, Down a) # toInteger :: Down a -> Integer #
Num a => Num (Down a)	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods (+) :: Down a -> Down a -> Down a # (-) :: Down a -> Down a -> Down a # (*) :: Down a -> Down a -> Down a # negate :: Down a -> Down a # abs :: Down a -> Down a # signum :: Down a -> Down a # fromInteger :: Integer -> Down a #
Ord a => Ord (Down a)	Since: base-4.6.0.0
Instance details Defined in Data.Ord Methods compare :: Down a -> Down a -> Ordering # (<) :: Down a -> Down a -> Bool # (<=) :: Down a -> Down a -> Bool # (>) :: Down a -> Down a -> Bool # (>=) :: Down a -> Down a -> Bool # max :: Down a -> Down a -> Down a # min :: Down a -> Down a -> Down a #
Read a => Read (Down a)	This instance would be equivalent to the derived instances of the `Down` newtype if the `getDown` field were removed Since: base-4.7.0.0
Instance details Defined in Data.Ord Methods readsPrec :: Int -> ReadS (Down a) # readList :: ReadS [Down a] # readPrec :: ReadPrec (Down a) # readListPrec :: ReadPrec [Down a] #
Real a => Real (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods toRational :: Down a -> Rational #
RealFloat a => RealFloat (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods floatRadix :: Down a -> Integer # floatDigits :: Down a -> Int # floatRange :: Down a -> (Int, Int) # decodeFloat :: Down a -> (Integer, Int) # encodeFloat :: Integer -> Int -> Down a # exponent :: Down a -> Int # significand :: Down a -> Down a # scaleFloat :: Int -> Down a -> Down a # isNaN :: Down a -> Bool # isInfinite :: Down a -> Bool # isDenormalized :: Down a -> Bool # isNegativeZero :: Down a -> Bool # isIEEE :: Down a -> Bool # atan2 :: Down a -> Down a -> Down a #
RealFrac a => RealFrac (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods properFraction :: Integral b => Down a -> (b, Down a) # truncate :: Integral b => Down a -> b # round :: Integral b => Down a -> b # ceiling :: Integral b => Down a -> b # floor :: Integral b => Down a -> b #
Show a => Show (Down a)	This instance would be equivalent to the derived instances of the `Down` newtype if the `getDown` field were removed Since: base-4.7.0.0
Instance details Defined in Data.Ord Methods showsPrec :: Int -> Down a -> ShowS # show :: Down a -> String # showList :: [Down a] -> ShowS #
Ix a => Ix (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods range :: (Down a, Down a) -> [Down a] # index :: (Down a, Down a) -> Down a -> Int # unsafeIndex :: (Down a, Down a) -> Down a -> Int # inRange :: (Down a, Down a) -> Down a -> Bool # rangeSize :: (Down a, Down a) -> Int # unsafeRangeSize :: (Down a, Down a) -> Int #
Generic (Down a)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Down a) :: Type -> Type # Methods from :: Down a -> Rep (Down a) x # to :: Rep (Down a) x -> Down a #
Semigroup a => Semigroup (Down a)	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods (<>) :: Down a -> Down a -> Down a # sconcat :: NonEmpty (Down a) -> Down a # stimes :: Integral b => b -> Down a -> Down a #
Monoid a => Monoid (Down a)	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods mempty :: Down a # mappend :: Down a -> Down a -> Down a # mconcat :: [Down a] -> Down a #
Storable a => Storable (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods sizeOf :: Down a -> Int # alignment :: Down a -> Int # peekElemOff :: Ptr (Down a) -> Int -> IO (Down a) # pokeElemOff :: Ptr (Down a) -> Int -> Down a -> IO () # peekByteOff :: Ptr b -> Int -> IO (Down a) # pokeByteOff :: Ptr b -> Int -> Down a -> IO () # peek :: Ptr (Down a) -> IO (Down a) # poke :: Ptr (Down a) -> Down a -> IO () #
Bits a => Bits (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods (.&.) :: Down a -> Down a -> Down a # (.\|.) :: Down a -> Down a -> Down a # xor :: Down a -> Down a -> Down a # complement :: Down a -> Down a # shift :: Down a -> Int -> Down a # rotate :: Down a -> Int -> Down a # zeroBits :: Down a # bit :: Int -> Down a # setBit :: Down a -> Int -> Down a # clearBit :: Down a -> Int -> Down a # complementBit :: Down a -> Int -> Down a # testBit :: Down a -> Int -> Bool # bitSizeMaybe :: Down a -> Maybe Int # bitSize :: Down a -> Int # isSigned :: Down a -> Bool # shiftL :: Down a -> Int -> Down a # unsafeShiftL :: Down a -> Int -> Down a # shiftR :: Down a -> Int -> Down a # unsafeShiftR :: Down a -> Int -> Down a # rotateL :: Down a -> Int -> Down a # rotateR :: Down a -> Int -> Down a # popCount :: Down a -> Int #
FiniteBits a => FiniteBits (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods finiteBitSize :: Down a -> Int # countLeadingZeros :: Down a -> Int # countTrailingZeros :: Down a -> Int #
Generic1 Down	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 Down :: k -> Type # Methods from1 :: forall (a :: k). Down a -> Rep1 Down a # to1 :: forall (a :: k). Rep1 Down a -> Down a #
type Rep (Down a)
Instance details Defined in GHC.Generics type Rep (Down a) = D1 ('MetaData "Down" "Data.Ord" "base" 'True) (C1 ('MetaCons "Down" 'PrefixI 'True) (S1 ('MetaSel ('Just "getDown") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
type Rep1 Down
Instance details Defined in GHC.Generics type Rep1 Down = D1 ('MetaData "Down" "Data.Ord" "base" 'True) (C1 ('MetaCons "Down" 'PrefixI 'True) (S1 ('MetaSel ('Just "getDown") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

comparing :: Ord a => (b -> a) -> b -> b -> Ordering #

comparing p x y = compare (p x) (p y)

Useful combinator for use in conjunction with the xxxBy family of functions from Data.List, for example:

  ... sortBy (comparing fst) ...

Enum

class Enum a where #

Class Enum defines operations on sequentially ordered types.

The enumFrom... methods are used in Haskell's translation of arithmetic sequences.

Instances of Enum may be derived for any enumeration type (types whose constructors have no fields). The nullary constructors are assumed to be numbered left-to-right by fromEnum from 0 through n-1. See Chapter 10 of the Haskell Report for more details.

For any type that is an instance of class Bounded as well as Enum, the following should hold:

The calls succ maxBound and pred minBound should result in a runtime error.
fromEnum and toEnum should give a runtime error if the result value is not representable in the result type. For example, toEnum 7 :: Bool is an error.
enumFrom and enumFromThen should be defined with an implicit bound, thus:

   enumFrom     x   = enumFromTo     x maxBound
   enumFromThen x y = enumFromThenTo x y bound
     where
       bound | fromEnum y >= fromEnum x = maxBound
             | otherwise                = minBound

Minimal complete definition

toEnum, fromEnum

Methods

fromEnum :: a -> Int #

Convert to an Int. It is implementation-dependent what fromEnum returns when applied to a value that is too large to fit in an Int.

enumFrom :: a -> [a] #

Used in Haskell's translation of [n..] with [n..] = enumFrom n, a possible implementation being enumFrom n = n : enumFrom (succ n). For example:

```
enumFrom 4 :: [Integer] = [4,5,6,7,...]
```

enumFrom 6 :: [Int] = [6,7,8,9,...,maxBound :: Int]

enumFromThen :: a -> a -> [a] #

Used in Haskell's translation of [n,n'..] with [n,n'..] = enumFromThen n n', a possible implementation being enumFromThen n n' = n : n' : worker (f x) (f x n'), worker s v = v : worker s (s v), x = fromEnum n' - fromEnum n and f n y | n > 0 = f (n - 1) (succ y) | n < 0 = f (n + 1) (pred y) | otherwise = y For example:

enumFromThen 4 6 :: [Integer] = [4,6,8,10...]

enumFromThen 6 2 :: [Int] = [6,2,-2,-6,...,minBound :: Int]

enumFromTo :: a -> a -> [a] #

Used in Haskell's translation of [n..m] with [n..m] = enumFromTo n m, a possible implementation being enumFromTo n m | n <= m = n : enumFromTo (succ n) m | otherwise = []. For example:

```
enumFromTo 6 10 :: [Int] = [6,7,8,9,10]
```
```
enumFromTo 42 1 :: [Integer] = []
```

enumFromThenTo :: a -> a -> a -> [a] #

Used in Haskell's translation of [n,n'..m] with [n,n'..m] = enumFromThenTo n n' m, a possible implementation being enumFromThenTo n n' m = worker (f x) (c x) n m, x = fromEnum n' - fromEnum n, c x = bool (>=) ((x 0) f n y | n > 0 = f (n - 1) (succ y) | n < 0 = f (n + 1) (pred y) | otherwise = y and worker s c v m | c v m = v : worker s c (s v) m | otherwise = [] For example:

enumFromThenTo 4 2 -6 :: [Integer] = [4,2,0,-2,-4,-6]

```
enumFromThenTo 6 8 2 :: [Int] = []
```

Instances

Instances details

Enum Bool	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Bool -> Bool # pred :: Bool -> Bool # toEnum :: Int -> Bool # fromEnum :: Bool -> Int # enumFrom :: Bool -> [Bool] # enumFromThen :: Bool -> Bool -> [Bool] # enumFromTo :: Bool -> Bool -> [Bool] # enumFromThenTo :: Bool -> Bool -> Bool -> [Bool] #
Enum Char	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Char -> Char # pred :: Char -> Char # toEnum :: Int -> Char # fromEnum :: Char -> Int # enumFrom :: Char -> [Char] # enumFromThen :: Char -> Char -> [Char] # enumFromTo :: Char -> Char -> [Char] # enumFromThenTo :: Char -> Char -> Char -> [Char] #
Enum Int	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Int -> Int # pred :: Int -> Int # toEnum :: Int -> Int # fromEnum :: Int -> Int # enumFrom :: Int -> [Int] # enumFromThen :: Int -> Int -> [Int] # enumFromTo :: Int -> Int -> [Int] # enumFromThenTo :: Int -> Int -> Int -> [Int] #
Enum Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods succ :: Int8 -> Int8 # pred :: Int8 -> Int8 # toEnum :: Int -> Int8 # fromEnum :: Int8 -> Int # enumFrom :: Int8 -> [Int8] # enumFromThen :: Int8 -> Int8 -> [Int8] # enumFromTo :: Int8 -> Int8 -> [Int8] # enumFromThenTo :: Int8 -> Int8 -> Int8 -> [Int8] #
Enum Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods succ :: Int16 -> Int16 # pred :: Int16 -> Int16 # toEnum :: Int -> Int16 # fromEnum :: Int16 -> Int # enumFrom :: Int16 -> [Int16] # enumFromThen :: Int16 -> Int16 -> [Int16] # enumFromTo :: Int16 -> Int16 -> [Int16] # enumFromThenTo :: Int16 -> Int16 -> Int16 -> [Int16] #
Enum Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods succ :: Int32 -> Int32 # pred :: Int32 -> Int32 # toEnum :: Int -> Int32 # fromEnum :: Int32 -> Int # enumFrom :: Int32 -> [Int32] # enumFromThen :: Int32 -> Int32 -> [Int32] # enumFromTo :: Int32 -> Int32 -> [Int32] # enumFromThenTo :: Int32 -> Int32 -> Int32 -> [Int32] #
Enum Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods succ :: Int64 -> Int64 # pred :: Int64 -> Int64 # toEnum :: Int -> Int64 # fromEnum :: Int64 -> Int # enumFrom :: Int64 -> [Int64] # enumFromThen :: Int64 -> Int64 -> [Int64] # enumFromTo :: Int64 -> Int64 -> [Int64] # enumFromThenTo :: Int64 -> Int64 -> Int64 -> [Int64] #
Enum Integer	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Integer -> Integer # pred :: Integer -> Integer # toEnum :: Int -> Integer # fromEnum :: Integer -> Int # enumFrom :: Integer -> [Integer] # enumFromThen :: Integer -> Integer -> [Integer] # enumFromTo :: Integer -> Integer -> [Integer] # enumFromThenTo :: Integer -> Integer -> Integer -> [Integer] #
Enum Natural	Since: base-4.8.0.0
Instance details Defined in GHC.Enum Methods succ :: Natural -> Natural # pred :: Natural -> Natural # toEnum :: Int -> Natural # fromEnum :: Natural -> Int # enumFrom :: Natural -> [Natural] # enumFromThen :: Natural -> Natural -> [Natural] # enumFromTo :: Natural -> Natural -> [Natural] # enumFromThenTo :: Natural -> Natural -> Natural -> [Natural] #
Enum Ordering	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Ordering -> Ordering # pred :: Ordering -> Ordering # toEnum :: Int -> Ordering # fromEnum :: Ordering -> Int # enumFrom :: Ordering -> [Ordering] # enumFromThen :: Ordering -> Ordering -> [Ordering] # enumFromTo :: Ordering -> Ordering -> [Ordering] # enumFromThenTo :: Ordering -> Ordering -> Ordering -> [Ordering] #
Enum Word	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: Word -> Word # pred :: Word -> Word # toEnum :: Int -> Word # fromEnum :: Word -> Int # enumFrom :: Word -> [Word] # enumFromThen :: Word -> Word -> [Word] # enumFromTo :: Word -> Word -> [Word] # enumFromThenTo :: Word -> Word -> Word -> [Word] #
Enum Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods succ :: Word8 -> Word8 # pred :: Word8 -> Word8 # toEnum :: Int -> Word8 # fromEnum :: Word8 -> Int # enumFrom :: Word8 -> [Word8] # enumFromThen :: Word8 -> Word8 -> [Word8] # enumFromTo :: Word8 -> Word8 -> [Word8] # enumFromThenTo :: Word8 -> Word8 -> Word8 -> [Word8] #
Enum Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods succ :: Word16 -> Word16 # pred :: Word16 -> Word16 # toEnum :: Int -> Word16 # fromEnum :: Word16 -> Int # enumFrom :: Word16 -> [Word16] # enumFromThen :: Word16 -> Word16 -> [Word16] # enumFromTo :: Word16 -> Word16 -> [Word16] # enumFromThenTo :: Word16 -> Word16 -> Word16 -> [Word16] #
Enum Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods succ :: Word32 -> Word32 # pred :: Word32 -> Word32 # toEnum :: Int -> Word32 # fromEnum :: Word32 -> Int # enumFrom :: Word32 -> [Word32] # enumFromThen :: Word32 -> Word32 -> [Word32] # enumFromTo :: Word32 -> Word32 -> [Word32] # enumFromThenTo :: Word32 -> Word32 -> Word32 -> [Word32] #
Enum Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods succ :: Word64 -> Word64 # pred :: Word64 -> Word64 # toEnum :: Int -> Word64 # fromEnum :: Word64 -> Int # enumFrom :: Word64 -> [Word64] # enumFromThen :: Word64 -> Word64 -> [Word64] # enumFromTo :: Word64 -> Word64 -> [Word64] # enumFromThenTo :: Word64 -> Word64 -> Word64 -> [Word64] #
Enum VecCount	Since: base-4.10.0.0
Instance details Defined in GHC.Enum Methods succ :: VecCount -> VecCount # pred :: VecCount -> VecCount # toEnum :: Int -> VecCount # fromEnum :: VecCount -> Int # enumFrom :: VecCount -> [VecCount] # enumFromThen :: VecCount -> VecCount -> [VecCount] # enumFromTo :: VecCount -> VecCount -> [VecCount] # enumFromThenTo :: VecCount -> VecCount -> VecCount -> [VecCount] #
Enum VecElem	Since: base-4.10.0.0
Instance details Defined in GHC.Enum Methods succ :: VecElem -> VecElem # pred :: VecElem -> VecElem # toEnum :: Int -> VecElem # fromEnum :: VecElem -> Int # enumFrom :: VecElem -> [VecElem] # enumFromThen :: VecElem -> VecElem -> [VecElem] # enumFromTo :: VecElem -> VecElem -> [VecElem] # enumFromThenTo :: VecElem -> VecElem -> VecElem -> [VecElem] #
Enum ()	Since: base-2.1
Instance details Defined in GHC.Enum Methods succ :: () -> () # pred :: () -> () # toEnum :: Int -> () # fromEnum :: () -> Int # enumFrom :: () -> [()] # enumFromThen :: () -> () -> [()] # enumFromTo :: () -> () -> [()] # enumFromThenTo :: () -> () -> () -> [()] #
Enum Associativity	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods succ :: Associativity -> Associativity # pred :: Associativity -> Associativity # toEnum :: Int -> Associativity # fromEnum :: Associativity -> Int # enumFrom :: Associativity -> [Associativity] # enumFromThen :: Associativity -> Associativity -> [Associativity] # enumFromTo :: Associativity -> Associativity -> [Associativity] # enumFromThenTo :: Associativity -> Associativity -> Associativity -> [Associativity] #
Enum SourceUnpackedness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods succ :: SourceUnpackedness -> SourceUnpackedness # pred :: SourceUnpackedness -> SourceUnpackedness # toEnum :: Int -> SourceUnpackedness # fromEnum :: SourceUnpackedness -> Int # enumFrom :: SourceUnpackedness -> [SourceUnpackedness] # enumFromThen :: SourceUnpackedness -> SourceUnpackedness -> [SourceUnpackedness] # enumFromTo :: SourceUnpackedness -> SourceUnpackedness -> [SourceUnpackedness] # enumFromThenTo :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness -> [SourceUnpackedness] #
Enum SourceStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods succ :: SourceStrictness -> SourceStrictness # pred :: SourceStrictness -> SourceStrictness # toEnum :: Int -> SourceStrictness # fromEnum :: SourceStrictness -> Int # enumFrom :: SourceStrictness -> [SourceStrictness] # enumFromThen :: SourceStrictness -> SourceStrictness -> [SourceStrictness] # enumFromTo :: SourceStrictness -> SourceStrictness -> [SourceStrictness] # enumFromThenTo :: SourceStrictness -> SourceStrictness -> SourceStrictness -> [SourceStrictness] #
Enum DecidedStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods succ :: DecidedStrictness -> DecidedStrictness # pred :: DecidedStrictness -> DecidedStrictness # toEnum :: Int -> DecidedStrictness # fromEnum :: DecidedStrictness -> Int # enumFrom :: DecidedStrictness -> [DecidedStrictness] # enumFromThen :: DecidedStrictness -> DecidedStrictness -> [DecidedStrictness] # enumFromTo :: DecidedStrictness -> DecidedStrictness -> [DecidedStrictness] # enumFromThenTo :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness -> [DecidedStrictness] #
Enum NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods succ :: NominalDiffTime -> NominalDiffTime # pred :: NominalDiffTime -> NominalDiffTime # toEnum :: Int -> NominalDiffTime # fromEnum :: NominalDiffTime -> Int # enumFrom :: NominalDiffTime -> [NominalDiffTime] # enumFromThen :: NominalDiffTime -> NominalDiffTime -> [NominalDiffTime] # enumFromTo :: NominalDiffTime -> NominalDiffTime -> [NominalDiffTime] # enumFromThenTo :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime -> [NominalDiffTime] #
Enum DiffTime
Instance details Defined in Data.Time.Clock.Internal.DiffTime Methods succ :: DiffTime -> DiffTime # pred :: DiffTime -> DiffTime # toEnum :: Int -> DiffTime # fromEnum :: DiffTime -> Int # enumFrom :: DiffTime -> [DiffTime] # enumFromThen :: DiffTime -> DiffTime -> [DiffTime] # enumFromTo :: DiffTime -> DiffTime -> [DiffTime] # enumFromThenTo :: DiffTime -> DiffTime -> DiffTime -> [DiffTime] #
Enum Day
Instance details Defined in Data.Time.Calendar.Days Methods succ :: Day -> Day # pred :: Day -> Day # toEnum :: Int -> Day # fromEnum :: Day -> Int # enumFrom :: Day -> [Day] # enumFromThen :: Day -> Day -> [Day] # enumFromTo :: Day -> Day -> [Day] # enumFromThenTo :: Day -> Day -> Day -> [Day] #
Enum Leniency Source #
Instance details Defined in Verset.Conv Methods succ :: Leniency -> Leniency # pred :: Leniency -> Leniency # toEnum :: Int -> Leniency # fromEnum :: Leniency -> Int # enumFrom :: Leniency -> [Leniency] # enumFromThen :: Leniency -> Leniency -> [Leniency] # enumFromTo :: Leniency -> Leniency -> [Leniency] # enumFromThenTo :: Leniency -> Leniency -> Leniency -> [Leniency] #
Integral a => Enum (Ratio a)	Since: base-2.0.1
Instance details Defined in GHC.Real Methods succ :: Ratio a -> Ratio a # pred :: Ratio a -> Ratio a # toEnum :: Int -> Ratio a # fromEnum :: Ratio a -> Int # enumFrom :: Ratio a -> [Ratio a] # enumFromThen :: Ratio a -> Ratio a -> [Ratio a] # enumFromTo :: Ratio a -> Ratio a -> [Ratio a] # enumFromThenTo :: Ratio a -> Ratio a -> Ratio a -> [Ratio a] #
Enum a => Enum (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods succ :: Min a -> Min a # pred :: Min a -> Min a # toEnum :: Int -> Min a # fromEnum :: Min a -> Int # enumFrom :: Min a -> [Min a] # enumFromThen :: Min a -> Min a -> [Min a] # enumFromTo :: Min a -> Min a -> [Min a] # enumFromThenTo :: Min a -> Min a -> Min a -> [Min a] #
Enum a => Enum (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods succ :: Max a -> Max a # pred :: Max a -> Max a # toEnum :: Int -> Max a # fromEnum :: Max a -> Int # enumFrom :: Max a -> [Max a] # enumFromThen :: Max a -> Max a -> [Max a] # enumFromTo :: Max a -> Max a -> [Max a] # enumFromThenTo :: Max a -> Max a -> Max a -> [Max a] #
Enum a => Enum (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods succ :: First a -> First a # pred :: First a -> First a # toEnum :: Int -> First a # fromEnum :: First a -> Int # enumFrom :: First a -> [First a] # enumFromThen :: First a -> First a -> [First a] # enumFromTo :: First a -> First a -> [First a] # enumFromThenTo :: First a -> First a -> First a -> [First a] #
Enum a => Enum (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods succ :: Last a -> Last a # pred :: Last a -> Last a # toEnum :: Int -> Last a # fromEnum :: Last a -> Int # enumFrom :: Last a -> [Last a] # enumFromThen :: Last a -> Last a -> [Last a] # enumFromTo :: Last a -> Last a -> [Last a] # enumFromThenTo :: Last a -> Last a -> Last a -> [Last a] #
Enum a => Enum (WrappedMonoid a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods succ :: WrappedMonoid a -> WrappedMonoid a # pred :: WrappedMonoid a -> WrappedMonoid a # toEnum :: Int -> WrappedMonoid a # fromEnum :: WrappedMonoid a -> Int # enumFrom :: WrappedMonoid a -> [WrappedMonoid a] # enumFromThen :: WrappedMonoid a -> WrappedMonoid a -> [WrappedMonoid a] # enumFromTo :: WrappedMonoid a -> WrappedMonoid a -> [WrappedMonoid a] # enumFromThenTo :: WrappedMonoid a -> WrappedMonoid a -> WrappedMonoid a -> [WrappedMonoid a] #
Enum a => Enum (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods succ :: Identity a -> Identity a # pred :: Identity a -> Identity a # toEnum :: Int -> Identity a # fromEnum :: Identity a -> Int # enumFrom :: Identity a -> [Identity a] # enumFromThen :: Identity a -> Identity a -> [Identity a] # enumFromTo :: Identity a -> Identity a -> [Identity a] # enumFromThenTo :: Identity a -> Identity a -> Identity a -> [Identity a] #
Enum a => Enum (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods succ :: Down a -> Down a # pred :: Down a -> Down a # toEnum :: Int -> Down a # fromEnum :: Down a -> Int # enumFrom :: Down a -> [Down a] # enumFromThen :: Down a -> Down a -> [Down a] # enumFromTo :: Down a -> Down a -> [Down a] # enumFromThenTo :: Down a -> Down a -> Down a -> [Down a] #
Enum (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods succ :: Proxy s -> Proxy s # pred :: Proxy s -> Proxy s # toEnum :: Int -> Proxy s # fromEnum :: Proxy s -> Int # enumFrom :: Proxy s -> [Proxy s] # enumFromThen :: Proxy s -> Proxy s -> [Proxy s] # enumFromTo :: Proxy s -> Proxy s -> [Proxy s] # enumFromThenTo :: Proxy s -> Proxy s -> Proxy s -> [Proxy s] #
Enum a => Enum (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods succ :: Const a b -> Const a b # pred :: Const a b -> Const a b # toEnum :: Int -> Const a b # fromEnum :: Const a b -> Int # enumFrom :: Const a b -> [Const a b] # enumFromThen :: Const a b -> Const a b -> [Const a b] # enumFromTo :: Const a b -> Const a b -> [Const a b] # enumFromThenTo :: Const a b -> Const a b -> Const a b -> [Const a b] #
Enum (f a) => Enum (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods succ :: Ap f a -> Ap f a # pred :: Ap f a -> Ap f a # toEnum :: Int -> Ap f a # fromEnum :: Ap f a -> Int # enumFrom :: Ap f a -> [Ap f a] # enumFromThen :: Ap f a -> Ap f a -> [Ap f a] # enumFromTo :: Ap f a -> Ap f a -> [Ap f a] # enumFromThenTo :: Ap f a -> Ap f a -> Ap f a -> [Ap f a] #
Enum (f a) => Enum (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods succ :: Alt f a -> Alt f a # pred :: Alt f a -> Alt f a # toEnum :: Int -> Alt f a # fromEnum :: Alt f a -> Int # enumFrom :: Alt f a -> [Alt f a] # enumFromThen :: Alt f a -> Alt f a -> [Alt f a] # enumFromTo :: Alt f a -> Alt f a -> [Alt f a] # enumFromThenTo :: Alt f a -> Alt f a -> Alt f a -> [Alt f a] #

toEnumMay :: (Enum a, Bounded a) => Int -> Maybe a #

toEnumDef :: (Enum a, Bounded a) => a -> Int -> a #

predMay :: (Enum a, Eq a, Bounded a) => a -> Maybe a #

predDef :: (Enum a, Eq a, Bounded a) => a -> a -> a #

succMay :: (Enum a, Eq a, Bounded a) => a -> Maybe a #

succDef :: (Enum a, Eq a, Bounded a) => a -> a -> a #

Bounded

class Bounded a where #

The Bounded class is used to name the upper and lower limits of a type. Ord is not a superclass of Bounded since types that are not totally ordered may also have upper and lower bounds.

The Bounded class may be derived for any enumeration type; minBound is the first constructor listed in the data declaration and maxBound is the last. Bounded may also be derived for single-constructor datatypes whose constituent types are in Bounded.

Methods

minBound :: a #

maxBound :: a #

Instances

Instances details

Bounded Bool	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Bool # maxBound :: Bool #
Bounded Char	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Char # maxBound :: Char #
Bounded Int	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Int # maxBound :: Int #
Bounded Int8	Since: base-2.1
Instance details Defined in GHC.Int Methods minBound :: Int8 # maxBound :: Int8 #
Bounded Int16	Since: base-2.1
Instance details Defined in GHC.Int Methods minBound :: Int16 # maxBound :: Int16 #
Bounded Int32	Since: base-2.1
Instance details Defined in GHC.Int Methods minBound :: Int32 # maxBound :: Int32 #
Bounded Int64	Since: base-2.1
Instance details Defined in GHC.Int Methods minBound :: Int64 # maxBound :: Int64 #
Bounded Ordering	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Ordering # maxBound :: Ordering #
Bounded Word	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: Word # maxBound :: Word #
Bounded Word8	Since: base-2.1
Instance details Defined in GHC.Word Methods minBound :: Word8 # maxBound :: Word8 #
Bounded Word16	Since: base-2.1
Instance details Defined in GHC.Word Methods minBound :: Word16 # maxBound :: Word16 #
Bounded Word32	Since: base-2.1
Instance details Defined in GHC.Word Methods minBound :: Word32 # maxBound :: Word32 #
Bounded Word64	Since: base-2.1
Instance details Defined in GHC.Word Methods minBound :: Word64 # maxBound :: Word64 #
Bounded VecCount	Since: base-4.10.0.0
Instance details Defined in GHC.Enum Methods minBound :: VecCount # maxBound :: VecCount #
Bounded VecElem	Since: base-4.10.0.0
Instance details Defined in GHC.Enum Methods minBound :: VecElem # maxBound :: VecElem #
Bounded ()	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: () # maxBound :: () #
Bounded All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods minBound :: All # maxBound :: All #
Bounded Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods minBound :: Any # maxBound :: Any #
Bounded Associativity	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods minBound :: Associativity # maxBound :: Associativity #
Bounded SourceUnpackedness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods minBound :: SourceUnpackedness # maxBound :: SourceUnpackedness #
Bounded SourceStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods minBound :: SourceStrictness # maxBound :: SourceStrictness #
Bounded DecidedStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods minBound :: DecidedStrictness # maxBound :: DecidedStrictness #
Bounded Leniency Source #
Instance details Defined in Verset.Conv Methods minBound :: Leniency # maxBound :: Leniency #
Bounded a => Bounded (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods minBound :: Min a # maxBound :: Min a #
Bounded a => Bounded (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods minBound :: Max a # maxBound :: Max a #
Bounded a => Bounded (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods minBound :: First a # maxBound :: First a #
Bounded a => Bounded (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods minBound :: Last a # maxBound :: Last a #
Bounded m => Bounded (WrappedMonoid m)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods minBound :: WrappedMonoid m # maxBound :: WrappedMonoid m #
Bounded a => Bounded (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods minBound :: Identity a # maxBound :: Identity a #
Bounded a => Bounded (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods minBound :: Dual a # maxBound :: Dual a #
Bounded a => Bounded (Sum a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods minBound :: Sum a # maxBound :: Sum a #
Bounded a => Bounded (Product a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods minBound :: Product a # maxBound :: Product a #
Bounded a => Bounded (Down a)	Since: base-4.14.0.0
Instance details Defined in Data.Ord Methods minBound :: Down a # maxBound :: Down a #
(Bounded a, Bounded b) => Bounded (a, b)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b) # maxBound :: (a, b) #
Bounded (Proxy t)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods minBound :: Proxy t # maxBound :: Proxy t #
(Bounded a, Bounded b, Bounded c) => Bounded (a, b, c)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c) # maxBound :: (a, b, c) #
Bounded a => Bounded (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods minBound :: Const a b # maxBound :: Const a b #
(Applicative f, Bounded a) => Bounded (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods minBound :: Ap f a # maxBound :: Ap f a #
(Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a, b, c, d)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d) # maxBound :: (a, b, c, d) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a, b, c, d, e)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e) # maxBound :: (a, b, c, d, e) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f) => Bounded (a, b, c, d, e, f)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f) # maxBound :: (a, b, c, d, e, f) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g) => Bounded (a, b, c, d, e, f, g)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g) # maxBound :: (a, b, c, d, e, f, g) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h) => Bounded (a, b, c, d, e, f, g, h)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h) # maxBound :: (a, b, c, d, e, f, g, h) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i) => Bounded (a, b, c, d, e, f, g, h, i)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i) # maxBound :: (a, b, c, d, e, f, g, h, i) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j) => Bounded (a, b, c, d, e, f, g, h, i, j)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j) # maxBound :: (a, b, c, d, e, f, g, h, i, j) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k) => Bounded (a, b, c, d, e, f, g, h, i, j, k)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k) # maxBound :: (a, b, c, d, e, f, g, h, i, j, k) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k, l) # maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m) # maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) #
(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n, Bounded o) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)	Since: base-2.1
Instance details Defined in GHC.Enum Methods minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) #

Algebraic type classes

Semigroup

newtype First a #

Use Option (First a) to get the behavior of First from Data.Monoid.

Constructors

First
Fields getFirst :: a

Instances

Instances details

Monad First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: First a -> (a -> First b) -> First b # (>>) :: First a -> First b -> First b # return :: a -> First a #
Functor First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fmap :: (a -> b) -> First a -> First b # (<$) :: a -> First b -> First a #
MonadFix First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mfix :: (a -> First a) -> First a #
Applicative First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> First a # (<>) :: First (a -> b) -> First a -> First b # liftA2 :: (a -> b -> c) -> First a -> First b -> First c # (>) :: First a -> First b -> First b # (<*) :: First a -> First b -> First a #
Foldable First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # toList :: First a -> [a] # null :: First a -> Bool # length :: First a -> Int # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # sum :: Num a => First a -> a # product :: Num a => First a -> a #
Traversable First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a -> f b) -> First a -> f (First b) # sequenceA :: Applicative f => First (f a) -> f (First a) # mapM :: Monad m => (a -> m b) -> First a -> m (First b) # sequence :: Monad m => First (m a) -> m (First a) #
Bounded a => Bounded (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods minBound :: First a # maxBound :: First a #
Enum a => Enum (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods succ :: First a -> First a # pred :: First a -> First a # toEnum :: Int -> First a # fromEnum :: First a -> Int # enumFrom :: First a -> [First a] # enumFromThen :: First a -> First a -> [First a] # enumFromTo :: First a -> First a -> [First a] # enumFromThenTo :: First a -> First a -> First a -> [First a] #
Eq a => Eq (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: First a -> First a -> Bool # (/=) :: First a -> First a -> Bool #
Data a => Data (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> First a -> c (First a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (First a) # toConstr :: First a -> Constr # dataTypeOf :: First a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (First a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (First a)) # gmapT :: (forall b. Data b => b -> b) -> First a -> First a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> First a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> First a -> r # gmapQ :: (forall d. Data d => d -> u) -> First a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> First a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> First a -> m (First a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> First a -> m (First a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> First a -> m (First a) #
Ord a => Ord (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: First a -> First a -> Ordering # (<) :: First a -> First a -> Bool # (<=) :: First a -> First a -> Bool # (>) :: First a -> First a -> Bool # (>=) :: First a -> First a -> Bool # max :: First a -> First a -> First a # min :: First a -> First a -> First a #
Read a => Read (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (First a) # readList :: ReadS [First a] # readPrec :: ReadPrec (First a) # readListPrec :: ReadPrec [First a] #
Show a => Show (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> First a -> ShowS # show :: First a -> String # showList :: [First a] -> ShowS #
Generic (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (First a) :: Type -> Type # Methods from :: First a -> Rep (First a) x # to :: Rep (First a) x -> First a #
Semigroup (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: First a -> First a -> First a # sconcat :: NonEmpty (First a) -> First a # stimes :: Integral b => b -> First a -> First a #
Generic1 First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 First :: k -> Type # Methods from1 :: forall (a :: k). First a -> Rep1 First a # to1 :: forall (a :: k). Rep1 First a -> First a #
type Rep (First a)
Instance details Defined in Data.Semigroup type Rep (First a) = D1 ('MetaData "First" "Data.Semigroup" "base" 'True) (C1 ('MetaCons "First" 'PrefixI 'True) (S1 ('MetaSel ('Just "getFirst") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
type Rep1 First
Instance details Defined in Data.Semigroup type Rep1 First = D1 ('MetaData "First" "Data.Semigroup" "base" 'True) (C1 ('MetaCons "First" 'PrefixI 'True) (S1 ('MetaSel ('Just "getFirst") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

newtype Last a #

Use Option (Last a) to get the behavior of Last from Data.Monoid

Constructors

Last
Fields getLast :: a

Instances

Instances details

Monad Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Last a -> (a -> Last b) -> Last b # (>>) :: Last a -> Last b -> Last b # return :: a -> Last a #
Functor Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fmap :: (a -> b) -> Last a -> Last b # (<$) :: a -> Last b -> Last a #
MonadFix Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mfix :: (a -> Last a) -> Last a #
Applicative Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Last a # (<>) :: Last (a -> b) -> Last a -> Last b # liftA2 :: (a -> b -> c) -> Last a -> Last b -> Last c # (>) :: Last a -> Last b -> Last b # (<*) :: Last a -> Last b -> Last a #
Foldable Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # toList :: Last a -> [a] # null :: Last a -> Bool # length :: Last a -> Int # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # minimum :: Ord a => Last a -> a # sum :: Num a => Last a -> a # product :: Num a => Last a -> a #
Traversable Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a -> f b) -> Last a -> f (Last b) # sequenceA :: Applicative f => Last (f a) -> f (Last a) # mapM :: Monad m => (a -> m b) -> Last a -> m (Last b) # sequence :: Monad m => Last (m a) -> m (Last a) #
Bounded a => Bounded (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods minBound :: Last a # maxBound :: Last a #
Enum a => Enum (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods succ :: Last a -> Last a # pred :: Last a -> Last a # toEnum :: Int -> Last a # fromEnum :: Last a -> Int # enumFrom :: Last a -> [Last a] # enumFromThen :: Last a -> Last a -> [Last a] # enumFromTo :: Last a -> Last a -> [Last a] # enumFromThenTo :: Last a -> Last a -> Last a -> [Last a] #
Eq a => Eq (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: Last a -> Last a -> Bool # (/=) :: Last a -> Last a -> Bool #
Data a => Data (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Last a -> c (Last a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Last a) # toConstr :: Last a -> Constr # dataTypeOf :: Last a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Last a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Last a)) # gmapT :: (forall b. Data b => b -> b) -> Last a -> Last a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Last a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Last a -> r # gmapQ :: (forall d. Data d => d -> u) -> Last a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Last a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Last a -> m (Last a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Last a -> m (Last a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Last a -> m (Last a) #
Ord a => Ord (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: Last a -> Last a -> Ordering # (<) :: Last a -> Last a -> Bool # (<=) :: Last a -> Last a -> Bool # (>) :: Last a -> Last a -> Bool # (>=) :: Last a -> Last a -> Bool # max :: Last a -> Last a -> Last a # min :: Last a -> Last a -> Last a #
Read a => Read (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (Last a) # readList :: ReadS [Last a] # readPrec :: ReadPrec (Last a) # readListPrec :: ReadPrec [Last a] #
Show a => Show (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> Last a -> ShowS # show :: Last a -> String # showList :: [Last a] -> ShowS #
Generic (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (Last a) :: Type -> Type # Methods from :: Last a -> Rep (Last a) x # to :: Rep (Last a) x -> Last a #
Semigroup (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: Last a -> Last a -> Last a # sconcat :: NonEmpty (Last a) -> Last a # stimes :: Integral b => b -> Last a -> Last a #
Generic1 Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 Last :: k -> Type # Methods from1 :: forall (a :: k). Last a -> Rep1 Last a # to1 :: forall (a :: k). Rep1 Last a -> Last a #
type Rep (Last a)
Instance details Defined in Data.Semigroup type Rep (Last a) = D1 ('MetaData "Last" "Data.Semigroup" "base" 'True) (C1 ('MetaCons "Last" 'PrefixI 'True) (S1 ('MetaSel ('Just "getLast") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
type Rep1 Last
Instance details Defined in Data.Semigroup type Rep1 Last = D1 ('MetaData "Last" "Data.Semigroup" "base" 'True) (C1 ('MetaCons "Last" 'PrefixI 'True) (S1 ('MetaSel ('Just "getLast") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

newtype Max a #

Constructors

Max
Fields getMax :: a

Instances

Instances details

Monad Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Max a -> (a -> Max b) -> Max b # (>>) :: Max a -> Max b -> Max b # return :: a -> Max a #
Functor Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fmap :: (a -> b) -> Max a -> Max b # (<$) :: a -> Max b -> Max a #
MonadFix Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mfix :: (a -> Max a) -> Max a #
Applicative Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Max a # (<>) :: Max (a -> b) -> Max a -> Max b # liftA2 :: (a -> b -> c) -> Max a -> Max b -> Max c # (>) :: Max a -> Max b -> Max b # (<*) :: Max a -> Max b -> Max a #
Foldable Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => Max m -> m # foldMap :: Monoid m => (a -> m) -> Max a -> m # foldMap' :: Monoid m => (a -> m) -> Max a -> m # foldr :: (a -> b -> b) -> b -> Max a -> b # foldr' :: (a -> b -> b) -> b -> Max a -> b # foldl :: (b -> a -> b) -> b -> Max a -> b # foldl' :: (b -> a -> b) -> b -> Max a -> b # foldr1 :: (a -> a -> a) -> Max a -> a # foldl1 :: (a -> a -> a) -> Max a -> a # toList :: Max a -> [a] # null :: Max a -> Bool # length :: Max a -> Int # elem :: Eq a => a -> Max a -> Bool # maximum :: Ord a => Max a -> a # minimum :: Ord a => Max a -> a # sum :: Num a => Max a -> a # product :: Num a => Max a -> a #
Traversable Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a -> f b) -> Max a -> f (Max b) # sequenceA :: Applicative f => Max (f a) -> f (Max a) # mapM :: Monad m => (a -> m b) -> Max a -> m (Max b) # sequence :: Monad m => Max (m a) -> m (Max a) #
Bounded a => Bounded (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods minBound :: Max a # maxBound :: Max a #
Enum a => Enum (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods succ :: Max a -> Max a # pred :: Max a -> Max a # toEnum :: Int -> Max a # fromEnum :: Max a -> Int # enumFrom :: Max a -> [Max a] # enumFromThen :: Max a -> Max a -> [Max a] # enumFromTo :: Max a -> Max a -> [Max a] # enumFromThenTo :: Max a -> Max a -> Max a -> [Max a] #
Eq a => Eq (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: Max a -> Max a -> Bool # (/=) :: Max a -> Max a -> Bool #
Data a => Data (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Max a -> c (Max a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Max a) # toConstr :: Max a -> Constr # dataTypeOf :: Max a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Max a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Max a)) # gmapT :: (forall b. Data b => b -> b) -> Max a -> Max a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Max a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Max a -> r # gmapQ :: (forall d. Data d => d -> u) -> Max a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Max a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Max a -> m (Max a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Max a -> m (Max a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Max a -> m (Max a) #
Num a => Num (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (+) :: Max a -> Max a -> Max a # (-) :: Max a -> Max a -> Max a # (*) :: Max a -> Max a -> Max a # negate :: Max a -> Max a # abs :: Max a -> Max a # signum :: Max a -> Max a # fromInteger :: Integer -> Max a #
Ord a => Ord (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: Max a -> Max a -> Ordering # (<) :: Max a -> Max a -> Bool # (<=) :: Max a -> Max a -> Bool # (>) :: Max a -> Max a -> Bool # (>=) :: Max a -> Max a -> Bool # max :: Max a -> Max a -> Max a # min :: Max a -> Max a -> Max a #
Read a => Read (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (Max a) # readList :: ReadS [Max a] # readPrec :: ReadPrec (Max a) # readListPrec :: ReadPrec [Max a] #
Show a => Show (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> Max a -> ShowS # show :: Max a -> String # showList :: [Max a] -> ShowS #
Generic (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (Max a) :: Type -> Type # Methods from :: Max a -> Rep (Max a) x # to :: Rep (Max a) x -> Max a #
Ord a => Semigroup (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: Max a -> Max a -> Max a # sconcat :: NonEmpty (Max a) -> Max a # stimes :: Integral b => b -> Max a -> Max a #
(Ord a, Bounded a) => Monoid (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mempty :: Max a # mappend :: Max a -> Max a -> Max a # mconcat :: [Max a] -> Max a #
Generic1 Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 Max :: k -> Type # Methods from1 :: forall (a :: k). Max a -> Rep1 Max a # to1 :: forall (a :: k). Rep1 Max a -> Max a #
type Rep (Max a)
Instance details Defined in Data.Semigroup type Rep (Max a) = D1 ('MetaData "Max" "Data.Semigroup" "base" 'True) (C1 ('MetaCons "Max" 'PrefixI 'True) (S1 ('MetaSel ('Just "getMax") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
type Rep1 Max
Instance details Defined in Data.Semigroup type Rep1 Max = D1 ('MetaData "Max" "Data.Semigroup" "base" 'True) (C1 ('MetaCons "Max" 'PrefixI 'True) (S1 ('MetaSel ('Just "getMax") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

newtype Min a #

Constructors

Min
Fields getMin :: a

Instances

Instances details

Monad Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Min a -> (a -> Min b) -> Min b # (>>) :: Min a -> Min b -> Min b # return :: a -> Min a #
Functor Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fmap :: (a -> b) -> Min a -> Min b # (<$) :: a -> Min b -> Min a #
MonadFix Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mfix :: (a -> Min a) -> Min a #
Applicative Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Min a # (<>) :: Min (a -> b) -> Min a -> Min b # liftA2 :: (a -> b -> c) -> Min a -> Min b -> Min c # (>) :: Min a -> Min b -> Min b # (<*) :: Min a -> Min b -> Min a #
Foldable Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => Min m -> m # foldMap :: Monoid m => (a -> m) -> Min a -> m # foldMap' :: Monoid m => (a -> m) -> Min a -> m # foldr :: (a -> b -> b) -> b -> Min a -> b # foldr' :: (a -> b -> b) -> b -> Min a -> b # foldl :: (b -> a -> b) -> b -> Min a -> b # foldl' :: (b -> a -> b) -> b -> Min a -> b # foldr1 :: (a -> a -> a) -> Min a -> a # foldl1 :: (a -> a -> a) -> Min a -> a # toList :: Min a -> [a] # null :: Min a -> Bool # length :: Min a -> Int # elem :: Eq a => a -> Min a -> Bool # maximum :: Ord a => Min a -> a # minimum :: Ord a => Min a -> a # sum :: Num a => Min a -> a # product :: Num a => Min a -> a #
Traversable Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a -> f b) -> Min a -> f (Min b) # sequenceA :: Applicative f => Min (f a) -> f (Min a) # mapM :: Monad m => (a -> m b) -> Min a -> m (Min b) # sequence :: Monad m => Min (m a) -> m (Min a) #
Bounded a => Bounded (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods minBound :: Min a # maxBound :: Min a #
Enum a => Enum (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods succ :: Min a -> Min a # pred :: Min a -> Min a # toEnum :: Int -> Min a # fromEnum :: Min a -> Int # enumFrom :: Min a -> [Min a] # enumFromThen :: Min a -> Min a -> [Min a] # enumFromTo :: Min a -> Min a -> [Min a] # enumFromThenTo :: Min a -> Min a -> Min a -> [Min a] #
Eq a => Eq (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (==) :: Min a -> Min a -> Bool # (/=) :: Min a -> Min a -> Bool #
Data a => Data (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Min a -> c (Min a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Min a) # toConstr :: Min a -> Constr # dataTypeOf :: Min a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Min a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Min a)) # gmapT :: (forall b. Data b => b -> b) -> Min a -> Min a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Min a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Min a -> r # gmapQ :: (forall d. Data d => d -> u) -> Min a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Min a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Min a -> m (Min a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Min a -> m (Min a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Min a -> m (Min a) #
Num a => Num (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (+) :: Min a -> Min a -> Min a # (-) :: Min a -> Min a -> Min a # (*) :: Min a -> Min a -> Min a # negate :: Min a -> Min a # abs :: Min a -> Min a # signum :: Min a -> Min a # fromInteger :: Integer -> Min a #
Ord a => Ord (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods compare :: Min a -> Min a -> Ordering # (<) :: Min a -> Min a -> Bool # (<=) :: Min a -> Min a -> Bool # (>) :: Min a -> Min a -> Bool # (>=) :: Min a -> Min a -> Bool # max :: Min a -> Min a -> Min a # min :: Min a -> Min a -> Min a #
Read a => Read (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods readsPrec :: Int -> ReadS (Min a) # readList :: ReadS [Min a] # readPrec :: ReadPrec (Min a) # readListPrec :: ReadPrec [Min a] #
Show a => Show (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods showsPrec :: Int -> Min a -> ShowS # show :: Min a -> String # showList :: [Min a] -> ShowS #
Generic (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (Min a) :: Type -> Type # Methods from :: Min a -> Rep (Min a) x # to :: Rep (Min a) x -> Min a #
Ord a => Semigroup (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: Min a -> Min a -> Min a # sconcat :: NonEmpty (Min a) -> Min a # stimes :: Integral b => b -> Min a -> Min a #
(Ord a, Bounded a) => Monoid (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mempty :: Min a # mappend :: Min a -> Min a -> Min a # mconcat :: [Min a] -> Min a #
Generic1 Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 Min :: k -> Type # Methods from1 :: forall (a :: k). Min a -> Rep1 Min a # to1 :: forall (a :: k). Rep1 Min a -> Min a #
type Rep (Min a)
Instance details Defined in Data.Semigroup type Rep (Min a) = D1 ('MetaData "Min" "Data.Semigroup" "base" 'True) (C1 ('MetaCons "Min" 'PrefixI 'True) (S1 ('MetaSel ('Just "getMin") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
type Rep1 Min
Instance details Defined in Data.Semigroup type Rep1 Min = D1 ('MetaData "Min" "Data.Semigroup" "base" 'True) (C1 ('MetaCons "Min" 'PrefixI 'True) (S1 ('MetaSel ('Just "getMin") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

class Semigroup a where #

The class of semigroups (types with an associative binary operation).

Instances should satisfy the following:

Associativity: x <> (y <> z) = (x <> y) <> z

Since: base-4.9.0.0

Minimal complete definition

(<>)

Methods

(<>) :: a -> a -> a infixr 6 #

An associative operation.

>>> [1,2,3] <> [4,5,6]
[1,2,3,4,5,6]

sconcat :: NonEmpty a -> a #

Reduce a non-empty list with <>

The default definition should be sufficient, but this can be overridden for efficiency.

>>> import Data.List.NonEmpty
>>> sconcat $ "Hello" :| [" ", "Haskell", "!"]
"Hello Haskell!"

stimes :: Integral b => b -> a -> a #

Repeat a value n times.

Given that this works on a Semigroup it is allowed to fail if you request 0 or fewer repetitions, and the default definition will do so.

By making this a member of the class, idempotent semigroups and monoids can upgrade this to execute in $\mathcal{O}(1)$ by picking stimes = stimesIdempotent or stimes = stimesIdempotentMonoid respectively.

>>> stimes 4 [1]
[1,1,1,1]

Instances

Instances details

Semigroup Ordering	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: Ordering -> Ordering -> Ordering # sconcat :: NonEmpty Ordering -> Ordering # stimes :: Integral b => b -> Ordering -> Ordering #
Semigroup ()	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: () -> () -> () # sconcat :: NonEmpty () -> () # stimes :: Integral b => b -> () -> () #
Semigroup Void	Since: base-4.9.0.0
Instance details Defined in Data.Void Methods (<>) :: Void -> Void -> Void # sconcat :: NonEmpty Void -> Void # stimes :: Integral b => b -> Void -> Void #
Semigroup All	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: All -> All -> All # sconcat :: NonEmpty All -> All # stimes :: Integral b => b -> All -> All #
Semigroup Any	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Any -> Any -> Any # sconcat :: NonEmpty Any -> Any # stimes :: Integral b => b -> Any -> Any #
Semigroup ByteString
Instance details Defined in Data.ByteString.Lazy.Internal Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString #
Semigroup ByteString
Instance details Defined in Data.ByteString.Internal Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString #
Semigroup [a]	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: [a] -> [a] -> [a] # sconcat :: NonEmpty [a] -> [a] # stimes :: Integral b => b -> [a] -> [a] #
Semigroup a => Semigroup (Maybe a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: Maybe a -> Maybe a -> Maybe a # sconcat :: NonEmpty (Maybe a) -> Maybe a # stimes :: Integral b => b -> Maybe a -> Maybe a #
Semigroup a => Semigroup (IO a)	Since: base-4.10.0.0
Instance details Defined in GHC.Base Methods (<>) :: IO a -> IO a -> IO a # sconcat :: NonEmpty (IO a) -> IO a # stimes :: Integral b => b -> IO a -> IO a #
Semigroup p => Semigroup (Par1 p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods (<>) :: Par1 p -> Par1 p -> Par1 p # sconcat :: NonEmpty (Par1 p) -> Par1 p # stimes :: Integral b => b -> Par1 p -> Par1 p #
Semigroup (Predicate a)
Instance details Defined in Data.Functor.Contravariant Methods (<>) :: Predicate a -> Predicate a -> Predicate a # sconcat :: NonEmpty (Predicate a) -> Predicate a # stimes :: Integral b => b -> Predicate a -> Predicate a #
Semigroup (Comparison a)
Instance details Defined in Data.Functor.Contravariant Methods (<>) :: Comparison a -> Comparison a -> Comparison a # sconcat :: NonEmpty (Comparison a) -> Comparison a # stimes :: Integral b => b -> Comparison a -> Comparison a #
Semigroup (Equivalence a)
Instance details Defined in Data.Functor.Contravariant Methods (<>) :: Equivalence a -> Equivalence a -> Equivalence a # sconcat :: NonEmpty (Equivalence a) -> Equivalence a # stimes :: Integral b => b -> Equivalence a -> Equivalence a #
Ord a => Semigroup (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: Min a -> Min a -> Min a # sconcat :: NonEmpty (Min a) -> Min a # stimes :: Integral b => b -> Min a -> Min a #
Ord a => Semigroup (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: Max a -> Max a -> Max a # sconcat :: NonEmpty (Max a) -> Max a # stimes :: Integral b => b -> Max a -> Max a #
Semigroup (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: First a -> First a -> First a # sconcat :: NonEmpty (First a) -> First a # stimes :: Integral b => b -> First a -> First a #
Semigroup (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: Last a -> Last a -> Last a # sconcat :: NonEmpty (Last a) -> Last a # stimes :: Integral b => b -> Last a -> Last a #
Monoid m => Semigroup (WrappedMonoid m)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # sconcat :: NonEmpty (WrappedMonoid m) -> WrappedMonoid m # stimes :: Integral b => b -> WrappedMonoid m -> WrappedMonoid m #
Semigroup a => Semigroup (Option a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (<>) :: Option a -> Option a -> Option a # sconcat :: NonEmpty (Option a) -> Option a # stimes :: Integral b => b -> Option a -> Option a #
Semigroup a => Semigroup (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods (<>) :: Identity a -> Identity a -> Identity a # sconcat :: NonEmpty (Identity a) -> Identity a # stimes :: Integral b => b -> Identity a -> Identity a #
Semigroup (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Monoid Methods (<>) :: First a -> First a -> First a # sconcat :: NonEmpty (First a) -> First a # stimes :: Integral b => b -> First a -> First a #
Semigroup (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Monoid Methods (<>) :: Last a -> Last a -> Last a # sconcat :: NonEmpty (Last a) -> Last a # stimes :: Integral b => b -> Last a -> Last a #
Semigroup a => Semigroup (Dual a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Dual a -> Dual a -> Dual a # sconcat :: NonEmpty (Dual a) -> Dual a # stimes :: Integral b => b -> Dual a -> Dual a #
Semigroup (Endo a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Endo a -> Endo a -> Endo a # sconcat :: NonEmpty (Endo a) -> Endo a # stimes :: Integral b => b -> Endo a -> Endo a #
Num a => Semigroup (Sum a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Sum a -> Sum a -> Sum a # sconcat :: NonEmpty (Sum a) -> Sum a # stimes :: Integral b => b -> Sum a -> Sum a #
Num a => Semigroup (Product a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Product a -> Product a -> Product a # sconcat :: NonEmpty (Product a) -> Product a # stimes :: Integral b => b -> Product a -> Product a #
Semigroup a => Semigroup (Down a)	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods (<>) :: Down a -> Down a -> Down a # sconcat :: NonEmpty (Down a) -> Down a # stimes :: Integral b => b -> Down a -> Down a #
Semigroup (NonEmpty a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: NonEmpty a -> NonEmpty a -> NonEmpty a # sconcat :: NonEmpty (NonEmpty a) -> NonEmpty a # stimes :: Integral b => b -> NonEmpty a -> NonEmpty a #
Ord a => Semigroup (Set a)	Since: containers-0.5.7
Instance details Defined in Data.Set.Internal Methods (<>) :: Set a -> Set a -> Set a # sconcat :: NonEmpty (Set a) -> Set a # stimes :: Integral b => b -> Set a -> Set a #
Semigroup (MergeSet a)
Instance details Defined in Data.Set.Internal Methods (<>) :: MergeSet a -> MergeSet a -> MergeSet a # sconcat :: NonEmpty (MergeSet a) -> MergeSet a # stimes :: Integral b => b -> MergeSet a -> MergeSet a #
Semigroup b => Semigroup (a -> b)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a -> b) -> (a -> b) -> a -> b # sconcat :: NonEmpty (a -> b) -> a -> b # stimes :: Integral b0 => b0 -> (a -> b) -> a -> b #
Semigroup (Either a b)	Since: base-4.9.0.0
Instance details Defined in Data.Either Methods (<>) :: Either a b -> Either a b -> Either a b # sconcat :: NonEmpty (Either a b) -> Either a b # stimes :: Integral b0 => b0 -> Either a b -> Either a b #
Semigroup (V1 p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods (<>) :: V1 p -> V1 p -> V1 p # sconcat :: NonEmpty (V1 p) -> V1 p # stimes :: Integral b => b -> V1 p -> V1 p #
Semigroup (U1 p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods (<>) :: U1 p -> U1 p -> U1 p # sconcat :: NonEmpty (U1 p) -> U1 p # stimes :: Integral b => b -> U1 p -> U1 p #
(Semigroup a, Semigroup b) => Semigroup (a, b)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a, b) -> (a, b) -> (a, b) # sconcat :: NonEmpty (a, b) -> (a, b) # stimes :: Integral b0 => b0 -> (a, b) -> (a, b) #
Semigroup a => Semigroup (Op a b)
Instance details Defined in Data.Functor.Contravariant Methods (<>) :: Op a b -> Op a b -> Op a b # sconcat :: NonEmpty (Op a b) -> Op a b # stimes :: Integral b0 => b0 -> Op a b -> Op a b #
Semigroup (Proxy s)	Since: base-4.9.0.0
Instance details Defined in Data.Proxy Methods (<>) :: Proxy s -> Proxy s -> Proxy s # sconcat :: NonEmpty (Proxy s) -> Proxy s # stimes :: Integral b => b -> Proxy s -> Proxy s #
Ord k => Semigroup (Map k v)
Instance details Defined in Data.Map.Internal Methods (<>) :: Map k v -> Map k v -> Map k v # sconcat :: NonEmpty (Map k v) -> Map k v # stimes :: Integral b => b -> Map k v -> Map k v #
Semigroup (f p) => Semigroup (Rec1 f p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods (<>) :: Rec1 f p -> Rec1 f p -> Rec1 f p # sconcat :: NonEmpty (Rec1 f p) -> Rec1 f p # stimes :: Integral b => b -> Rec1 f p -> Rec1 f p #
(Semigroup a, Semigroup b, Semigroup c) => Semigroup (a, b, c)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a, b, c) -> (a, b, c) -> (a, b, c) # sconcat :: NonEmpty (a, b, c) -> (a, b, c) # stimes :: Integral b0 => b0 -> (a, b, c) -> (a, b, c) #
Semigroup a => Semigroup (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (<>) :: Const a b -> Const a b -> Const a b # sconcat :: NonEmpty (Const a b) -> Const a b # stimes :: Integral b0 => b0 -> Const a b -> Const a b #
(Applicative f, Semigroup a) => Semigroup (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods (<>) :: Ap f a -> Ap f a -> Ap f a # sconcat :: NonEmpty (Ap f a) -> Ap f a # stimes :: Integral b => b -> Ap f a -> Ap f a #
Alternative f => Semigroup (Alt f a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Alt f a -> Alt f a -> Alt f a # sconcat :: NonEmpty (Alt f a) -> Alt f a # stimes :: Integral b => b -> Alt f a -> Alt f a #
Semigroup c => Semigroup (K1 i c p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods (<>) :: K1 i c p -> K1 i c p -> K1 i c p # sconcat :: NonEmpty (K1 i c p) -> K1 i c p # stimes :: Integral b => b -> K1 i c p -> K1 i c p #
(Semigroup (f p), Semigroup (g p)) => Semigroup ((f :*: g) p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods (<>) :: (f :: g) p -> (f :: g) p -> (f :: g) p # sconcat :: NonEmpty ((f :: g) p) -> (f :: g) p # stimes :: Integral b => b -> (f :: g) p -> (f :*: g) p #
(Semigroup a, Semigroup b, Semigroup c, Semigroup d) => Semigroup (a, b, c, d)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d) # sconcat :: NonEmpty (a, b, c, d) -> (a, b, c, d) # stimes :: Integral b0 => b0 -> (a, b, c, d) -> (a, b, c, d) #
Semigroup (f p) => Semigroup (M1 i c f p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods (<>) :: M1 i c f p -> M1 i c f p -> M1 i c f p # sconcat :: NonEmpty (M1 i c f p) -> M1 i c f p # stimes :: Integral b => b -> M1 i c f p -> M1 i c f p #
Semigroup (f (g p)) => Semigroup ((f :.: g) p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods (<>) :: (f :.: g) p -> (f :.: g) p -> (f :.: g) p # sconcat :: NonEmpty ((f :.: g) p) -> (f :.: g) p # stimes :: Integral b => b -> (f :.: g) p -> (f :.: g) p #
(Semigroup a, Semigroup b, Semigroup c, Semigroup d, Semigroup e) => Semigroup (a, b, c, d, e)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (<>) :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) # sconcat :: NonEmpty (a, b, c, d, e) -> (a, b, c, d, e) # stimes :: Integral b0 => b0 -> (a, b, c, d, e) -> (a, b, c, d, e) #

Monoid

newtype All #

Boolean monoid under conjunction (&&).

>>> getAll (All True <> mempty <> All False)
False

>>> getAll (mconcat (map (\x -> All (even x)) [2,4,6,7,8]))
False

Constructors

All
Fields getAll :: Bool

Instances

Instances details

Bounded All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods minBound :: All # maxBound :: All #
Eq All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods (==) :: All -> All -> Bool # (/=) :: All -> All -> Bool #
Ord All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods compare :: All -> All -> Ordering # (<) :: All -> All -> Bool # (<=) :: All -> All -> Bool # (>) :: All -> All -> Bool # (>=) :: All -> All -> Bool # max :: All -> All -> All # min :: All -> All -> All #
Read All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS All # readList :: ReadS [All] # readPrec :: ReadPrec All # readListPrec :: ReadPrec [All] #
Show All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> All -> ShowS # show :: All -> String # showList :: [All] -> ShowS #
Generic All	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep All :: Type -> Type # Methods from :: All -> Rep All x # to :: Rep All x -> All #
Semigroup All	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: All -> All -> All # sconcat :: NonEmpty All -> All # stimes :: Integral b => b -> All -> All #
Monoid All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: All # mappend :: All -> All -> All # mconcat :: [All] -> All #
type Rep All
Instance details Defined in Data.Semigroup.Internal type Rep All = D1 ('MetaData "All" "Data.Semigroup.Internal" "base" 'True) (C1 ('MetaCons "All" 'PrefixI 'True) (S1 ('MetaSel ('Just "getAll") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Bool)))

newtype Alt (f :: k -> Type) (a :: k) #

Monoid under <|>.

>>> getAlt (Alt (Just 12) <> Alt (Just 24))
Just 12

>>> getAlt $ Alt Nothing <> Alt (Just 24)
Just 24

Since: base-4.8.0.0

Constructors

Alt
Fields getAlt :: f a

Instances

Instances details

Generic1 (Alt f :: k -> Type)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep1 (Alt f) :: k -> Type # Methods from1 :: forall (a :: k0). Alt f a -> Rep1 (Alt f) a # to1 :: forall (a :: k0). Rep1 (Alt f) a -> Alt f a #
Monad f => Monad (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (>>=) :: Alt f a -> (a -> Alt f b) -> Alt f b # (>>) :: Alt f a -> Alt f b -> Alt f b # return :: a -> Alt f a #
Functor f => Functor (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods fmap :: (a -> b) -> Alt f a -> Alt f b # (<$) :: a -> Alt f b -> Alt f a #
MonadFix f => MonadFix (Alt f)	Since: base-4.8.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Alt f a) -> Alt f a #
Applicative f => Applicative (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Alt f a # (<>) :: Alt f (a -> b) -> Alt f a -> Alt f b # liftA2 :: (a -> b -> c) -> Alt f a -> Alt f b -> Alt f c # (>) :: Alt f a -> Alt f b -> Alt f b # (<*) :: Alt f a -> Alt f b -> Alt f a #
Foldable f => Foldable (Alt f)	Since: base-4.12.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Alt f m -> m # foldMap :: Monoid m => (a -> m) -> Alt f a -> m # foldMap' :: Monoid m => (a -> m) -> Alt f a -> m # foldr :: (a -> b -> b) -> b -> Alt f a -> b # foldr' :: (a -> b -> b) -> b -> Alt f a -> b # foldl :: (b -> a -> b) -> b -> Alt f a -> b # foldl' :: (b -> a -> b) -> b -> Alt f a -> b # foldr1 :: (a -> a -> a) -> Alt f a -> a # foldl1 :: (a -> a -> a) -> Alt f a -> a # toList :: Alt f a -> [a] # null :: Alt f a -> Bool # length :: Alt f a -> Int # elem :: Eq a => a -> Alt f a -> Bool # maximum :: Ord a => Alt f a -> a # minimum :: Ord a => Alt f a -> a # sum :: Num a => Alt f a -> a # product :: Num a => Alt f a -> a #
Traversable f => Traversable (Alt f)	Since: base-4.12.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> Alt f a -> f0 (Alt f b) # sequenceA :: Applicative f0 => Alt f (f0 a) -> f0 (Alt f a) # mapM :: Monad m => (a -> m b) -> Alt f a -> m (Alt f b) # sequence :: Monad m => Alt f (m a) -> m (Alt f a) #
Contravariant f => Contravariant (Alt f)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Alt f b -> Alt f a # (>$) :: b -> Alt f b -> Alt f a #
Alternative f => Alternative (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods empty :: Alt f a # (<\|>) :: Alt f a -> Alt f a -> Alt f a # some :: Alt f a -> Alt f [a] # many :: Alt f a -> Alt f [a] #
MonadPlus f => MonadPlus (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods mzero :: Alt f a # mplus :: Alt f a -> Alt f a -> Alt f a #
Enum (f a) => Enum (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods succ :: Alt f a -> Alt f a # pred :: Alt f a -> Alt f a # toEnum :: Int -> Alt f a # fromEnum :: Alt f a -> Int # enumFrom :: Alt f a -> [Alt f a] # enumFromThen :: Alt f a -> Alt f a -> [Alt f a] # enumFromTo :: Alt f a -> Alt f a -> [Alt f a] # enumFromThenTo :: Alt f a -> Alt f a -> Alt f a -> [Alt f a] #
Eq (f a) => Eq (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (==) :: Alt f a -> Alt f a -> Bool # (/=) :: Alt f a -> Alt f a -> Bool #
Num (f a) => Num (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (+) :: Alt f a -> Alt f a -> Alt f a # (-) :: Alt f a -> Alt f a -> Alt f a # (*) :: Alt f a -> Alt f a -> Alt f a # negate :: Alt f a -> Alt f a # abs :: Alt f a -> Alt f a # signum :: Alt f a -> Alt f a # fromInteger :: Integer -> Alt f a #
Ord (f a) => Ord (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods compare :: Alt f a -> Alt f a -> Ordering # (<) :: Alt f a -> Alt f a -> Bool # (<=) :: Alt f a -> Alt f a -> Bool # (>) :: Alt f a -> Alt f a -> Bool # (>=) :: Alt f a -> Alt f a -> Bool # max :: Alt f a -> Alt f a -> Alt f a # min :: Alt f a -> Alt f a -> Alt f a #
Read (f a) => Read (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS (Alt f a) # readList :: ReadS [Alt f a] # readPrec :: ReadPrec (Alt f a) # readListPrec :: ReadPrec [Alt f a] #
Show (f a) => Show (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> Alt f a -> ShowS # show :: Alt f a -> String # showList :: [Alt f a] -> ShowS #
Generic (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep (Alt f a) :: Type -> Type # Methods from :: Alt f a -> Rep (Alt f a) x # to :: Rep (Alt f a) x -> Alt f a #
Alternative f => Semigroup (Alt f a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Alt f a -> Alt f a -> Alt f a # sconcat :: NonEmpty (Alt f a) -> Alt f a # stimes :: Integral b => b -> Alt f a -> Alt f a #
Alternative f => Monoid (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Alt f a # mappend :: Alt f a -> Alt f a -> Alt f a # mconcat :: [Alt f a] -> Alt f a #
type Rep1 (Alt f :: k -> Type)
Instance details Defined in Data.Semigroup.Internal type Rep1 (Alt f :: k -> Type) = D1 ('MetaData "Alt" "Data.Semigroup.Internal" "base" 'True) (C1 ('MetaCons "Alt" 'PrefixI 'True) (S1 ('MetaSel ('Just "getAlt") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 f)))
type Rep (Alt f a)
Instance details Defined in Data.Semigroup.Internal type Rep (Alt f a) = D1 ('MetaData "Alt" "Data.Semigroup.Internal" "base" 'True) (C1 ('MetaCons "Alt" 'PrefixI 'True) (S1 ('MetaSel ('Just "getAlt") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (f a))))

newtype Any #

Boolean monoid under disjunction (||).

>>> getAny (Any True <> mempty <> Any False)
True

>>> getAny (mconcat (map (\x -> Any (even x)) [2,4,6,7,8]))
True

Constructors

Any
Fields getAny :: Bool

Instances

Instances details

Bounded Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods minBound :: Any # maxBound :: Any #
Eq Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods (==) :: Any -> Any -> Bool # (/=) :: Any -> Any -> Bool #
Ord Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods compare :: Any -> Any -> Ordering # (<) :: Any -> Any -> Bool # (<=) :: Any -> Any -> Bool # (>) :: Any -> Any -> Bool # (>=) :: Any -> Any -> Bool # max :: Any -> Any -> Any # min :: Any -> Any -> Any #
Read Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS Any # readList :: ReadS [Any] # readPrec :: ReadPrec Any # readListPrec :: ReadPrec [Any] #
Show Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> Any -> ShowS # show :: Any -> String # showList :: [Any] -> ShowS #
Generic Any	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep Any :: Type -> Type # Methods from :: Any -> Rep Any x # to :: Rep Any x -> Any #
Semigroup Any	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Any -> Any -> Any # sconcat :: NonEmpty Any -> Any # stimes :: Integral b => b -> Any -> Any #
Monoid Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Any # mappend :: Any -> Any -> Any # mconcat :: [Any] -> Any #
type Rep Any
Instance details Defined in Data.Semigroup.Internal type Rep Any = D1 ('MetaData "Any" "Data.Semigroup.Internal" "base" 'True) (C1 ('MetaCons "Any" 'PrefixI 'True) (S1 ('MetaSel ('Just "getAny") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Bool)))

newtype Dual a #

The dual of a Monoid, obtained by swapping the arguments of mappend.

>>> getDual (mappend (Dual "Hello") (Dual "World"))
"WorldHello"

Constructors

Dual
Fields getDual :: a

Instances

Instances details

Monad Dual	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (>>=) :: Dual a -> (a -> Dual b) -> Dual b # (>>) :: Dual a -> Dual b -> Dual b # return :: a -> Dual a #
Functor Dual	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods fmap :: (a -> b) -> Dual a -> Dual b # (<$) :: a -> Dual b -> Dual a #
MonadFix Dual	Since: base-4.8.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Dual a) -> Dual a #
Applicative Dual	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Dual a # (<>) :: Dual (a -> b) -> Dual a -> Dual b # liftA2 :: (a -> b -> c) -> Dual a -> Dual b -> Dual c # (>) :: Dual a -> Dual b -> Dual b # (<*) :: Dual a -> Dual b -> Dual a #
Foldable Dual	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Dual m -> m # foldMap :: Monoid m => (a -> m) -> Dual a -> m # foldMap' :: Monoid m => (a -> m) -> Dual a -> m # foldr :: (a -> b -> b) -> b -> Dual a -> b # foldr' :: (a -> b -> b) -> b -> Dual a -> b # foldl :: (b -> a -> b) -> b -> Dual a -> b # foldl' :: (b -> a -> b) -> b -> Dual a -> b # foldr1 :: (a -> a -> a) -> Dual a -> a # foldl1 :: (a -> a -> a) -> Dual a -> a # toList :: Dual a -> [a] # null :: Dual a -> Bool # length :: Dual a -> Int # elem :: Eq a => a -> Dual a -> Bool # maximum :: Ord a => Dual a -> a # minimum :: Ord a => Dual a -> a # sum :: Num a => Dual a -> a # product :: Num a => Dual a -> a #
Traversable Dual	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Dual a -> f (Dual b) # sequenceA :: Applicative f => Dual (f a) -> f (Dual a) # mapM :: Monad m => (a -> m b) -> Dual a -> m (Dual b) # sequence :: Monad m => Dual (m a) -> m (Dual a) #
Bounded a => Bounded (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods minBound :: Dual a # maxBound :: Dual a #
Eq a => Eq (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods (==) :: Dual a -> Dual a -> Bool # (/=) :: Dual a -> Dual a -> Bool #
Ord a => Ord (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods compare :: Dual a -> Dual a -> Ordering # (<) :: Dual a -> Dual a -> Bool # (<=) :: Dual a -> Dual a -> Bool # (>) :: Dual a -> Dual a -> Bool # (>=) :: Dual a -> Dual a -> Bool # max :: Dual a -> Dual a -> Dual a # min :: Dual a -> Dual a -> Dual a #
Read a => Read (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods readsPrec :: Int -> ReadS (Dual a) # readList :: ReadS [Dual a] # readPrec :: ReadPrec (Dual a) # readListPrec :: ReadPrec [Dual a] #
Show a => Show (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods showsPrec :: Int -> Dual a -> ShowS # show :: Dual a -> String # showList :: [Dual a] -> ShowS #
Generic (Dual a)	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep (Dual a) :: Type -> Type # Methods from :: Dual a -> Rep (Dual a) x # to :: Rep (Dual a) x -> Dual a #
Semigroup a => Semigroup (Dual a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Dual a -> Dual a -> Dual a # sconcat :: NonEmpty (Dual a) -> Dual a # stimes :: Integral b => b -> Dual a -> Dual a #
Monoid a => Monoid (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Dual a # mappend :: Dual a -> Dual a -> Dual a # mconcat :: [Dual a] -> Dual a #
Generic1 Dual	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep1 Dual :: k -> Type # Methods from1 :: forall (a :: k). Dual a -> Rep1 Dual a # to1 :: forall (a :: k). Rep1 Dual a -> Dual a #
type Rep (Dual a)
Instance details Defined in Data.Semigroup.Internal type Rep (Dual a) = D1 ('MetaData "Dual" "Data.Semigroup.Internal" "base" 'True) (C1 ('MetaCons "Dual" 'PrefixI 'True) (S1 ('MetaSel ('Just "getDual") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
type Rep1 Dual
Instance details Defined in Data.Semigroup.Internal type Rep1 Dual = D1 ('MetaData "Dual" "Data.Semigroup.Internal" "base" 'True) (C1 ('MetaCons "Dual" 'PrefixI 'True) (S1 ('MetaSel ('Just "getDual") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

newtype Endo a #

The monoid of endomorphisms under composition.

>>> let computation = Endo ("Hello, " ++) <> Endo (++ "!")
>>> appEndo computation "Haskell"
"Hello, Haskell!"

Constructors

Endo
Fields appEndo :: a -> a

Instances

Instances details

Generic (Endo a)	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep (Endo a) :: Type -> Type # Methods from :: Endo a -> Rep (Endo a) x # to :: Rep (Endo a) x -> Endo a #
Semigroup (Endo a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup.Internal Methods (<>) :: Endo a -> Endo a -> Endo a # sconcat :: NonEmpty (Endo a) -> Endo a # stimes :: Integral b => b -> Endo a -> Endo a #
Monoid (Endo a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Endo a # mappend :: Endo a -> Endo a -> Endo a # mconcat :: [Endo a] -> Endo a #
type Rep (Endo a)
Instance details Defined in Data.Semigroup.Internal type Rep (Endo a) = D1 ('MetaData "Endo" "Data.Semigroup.Internal" "base" 'True) (C1 ('MetaCons "Endo" 'PrefixI 'True) (S1 ('MetaSel ('Just "appEndo") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (a -> a))))

class Semigroup a => Monoid a where #

The class of monoids (types with an associative binary operation that has an identity). Instances should satisfy the following:

Right identity: x <> mempty = x
Left identity: mempty <> x = x
Associativity: x <> (y <> z) = (x <> y) <> z (Semigroup law)
Concatenation: mconcat = foldr (<>) mempty

The method names refer to the monoid of lists under concatenation, but there are many other instances.

Some types can be viewed as a monoid in more than one way, e.g. both addition and multiplication on numbers. In such cases we often define newtypes and make those instances of Monoid, e.g. Sum and Product.

NOTE: Semigroup is a superclass of Monoid since base-4.11.0.0.

Minimal complete definition

mempty

Methods

mempty :: a #

Identity of mappend

>>> "Hello world" <> mempty
"Hello world"

mappend :: a -> a -> a #

An associative operation

NOTE: This method is redundant and has the default implementation mappend = (<>) since base-4.11.0.0. Should it be implemented manually, since mappend is a synonym for (<>), it is expected that the two functions are defined the same way. In a future GHC release mappend will be removed from Monoid.

mconcat :: [a] -> a #

Fold a list using the monoid.

For most types, the default definition for mconcat will be used, but the function is included in the class definition so that an optimized version can be provided for specific types.

>>> mconcat ["Hello", " ", "Haskell", "!"]
"Hello Haskell!"

Instances

Instances details

Monoid Ordering	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: Ordering # mappend :: Ordering -> Ordering -> Ordering # mconcat :: [Ordering] -> Ordering #
Monoid ()	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: () # mappend :: () -> () -> () # mconcat :: [()] -> () #
Monoid All	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: All # mappend :: All -> All -> All # mconcat :: [All] -> All #
Monoid Any	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Any # mappend :: Any -> Any -> Any # mconcat :: [Any] -> Any #
Monoid ByteString
Instance details Defined in Data.ByteString.Lazy.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString #
Monoid ByteString
Instance details Defined in Data.ByteString.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString #
Monoid [a]	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: [a] # mappend :: [a] -> [a] -> [a] # mconcat :: [[a]] -> [a] #
Semigroup a => Monoid (Maybe a)	Lift a semigroup into `Maybe` forming a `Monoid` according to http://en.wikipedia.org/wiki/Monoid: "Any semigroup `S` may be turned into a monoid simply by adjoining an element `e` not in `S` and defining `ee = e` and `es = s = se` for all `s ∈ S`." Since 4.11.0: constraint on inner `a` value generalised from `Monoid` to `Semigroup`. Since: base-2.1*
Instance details Defined in GHC.Base Methods mempty :: Maybe a # mappend :: Maybe a -> Maybe a -> Maybe a # mconcat :: [Maybe a] -> Maybe a #
Monoid a => Monoid (IO a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods mempty :: IO a # mappend :: IO a -> IO a -> IO a # mconcat :: [IO a] -> IO a #
Monoid p => Monoid (Par1 p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods mempty :: Par1 p # mappend :: Par1 p -> Par1 p -> Par1 p # mconcat :: [Par1 p] -> Par1 p #
Monoid (Predicate a)
Instance details Defined in Data.Functor.Contravariant Methods mempty :: Predicate a # mappend :: Predicate a -> Predicate a -> Predicate a # mconcat :: [Predicate a] -> Predicate a #
Monoid (Comparison a)
Instance details Defined in Data.Functor.Contravariant Methods mempty :: Comparison a # mappend :: Comparison a -> Comparison a -> Comparison a # mconcat :: [Comparison a] -> Comparison a #
Monoid (Equivalence a)
Instance details Defined in Data.Functor.Contravariant Methods mempty :: Equivalence a # mappend :: Equivalence a -> Equivalence a -> Equivalence a # mconcat :: [Equivalence a] -> Equivalence a #
(Ord a, Bounded a) => Monoid (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mempty :: Min a # mappend :: Min a -> Min a -> Min a # mconcat :: [Min a] -> Min a #
(Ord a, Bounded a) => Monoid (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mempty :: Max a # mappend :: Max a -> Max a -> Max a # mconcat :: [Max a] -> Max a #
Monoid m => Monoid (WrappedMonoid m)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mempty :: WrappedMonoid m # mappend :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # mconcat :: [WrappedMonoid m] -> WrappedMonoid m #
Semigroup a => Monoid (Option a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mempty :: Option a # mappend :: Option a -> Option a -> Option a # mconcat :: [Option a] -> Option a #
Monoid a => Monoid (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods mempty :: Identity a # mappend :: Identity a -> Identity a -> Identity a # mconcat :: [Identity a] -> Identity a #
Monoid (First a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods mempty :: First a # mappend :: First a -> First a -> First a # mconcat :: [First a] -> First a #
Monoid (Last a)	Since: base-2.1
Instance details Defined in Data.Monoid Methods mempty :: Last a # mappend :: Last a -> Last a -> Last a # mconcat :: [Last a] -> Last a #
Monoid a => Monoid (Dual a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Dual a # mappend :: Dual a -> Dual a -> Dual a # mconcat :: [Dual a] -> Dual a #
Monoid (Endo a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Endo a # mappend :: Endo a -> Endo a -> Endo a # mconcat :: [Endo a] -> Endo a #
Num a => Monoid (Sum a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Sum a # mappend :: Sum a -> Sum a -> Sum a # mconcat :: [Sum a] -> Sum a #
Num a => Monoid (Product a)	Since: base-2.1
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Product a # mappend :: Product a -> Product a -> Product a # mconcat :: [Product a] -> Product a #
Monoid a => Monoid (Down a)	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods mempty :: Down a # mappend :: Down a -> Down a -> Down a # mconcat :: [Down a] -> Down a #
Ord a => Monoid (Set a)
Instance details Defined in Data.Set.Internal Methods mempty :: Set a # mappend :: Set a -> Set a -> Set a # mconcat :: [Set a] -> Set a #
Monoid (MergeSet a)
Instance details Defined in Data.Set.Internal Methods mempty :: MergeSet a # mappend :: MergeSet a -> MergeSet a -> MergeSet a # mconcat :: [MergeSet a] -> MergeSet a #
Monoid b => Monoid (a -> b)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: a -> b # mappend :: (a -> b) -> (a -> b) -> a -> b # mconcat :: [a -> b] -> a -> b #
Monoid (U1 p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods mempty :: U1 p # mappend :: U1 p -> U1 p -> U1 p # mconcat :: [U1 p] -> U1 p #
(Monoid a, Monoid b) => Monoid (a, b)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: (a, b) # mappend :: (a, b) -> (a, b) -> (a, b) # mconcat :: [(a, b)] -> (a, b) #
Monoid a => Monoid (Op a b)
Instance details Defined in Data.Functor.Contravariant Methods mempty :: Op a b # mappend :: Op a b -> Op a b -> Op a b # mconcat :: [Op a b] -> Op a b #
Monoid (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods mempty :: Proxy s # mappend :: Proxy s -> Proxy s -> Proxy s # mconcat :: [Proxy s] -> Proxy s #
Ord k => Monoid (Map k v)
Instance details Defined in Data.Map.Internal Methods mempty :: Map k v # mappend :: Map k v -> Map k v -> Map k v # mconcat :: [Map k v] -> Map k v #
Monoid (f p) => Monoid (Rec1 f p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods mempty :: Rec1 f p # mappend :: Rec1 f p -> Rec1 f p -> Rec1 f p # mconcat :: [Rec1 f p] -> Rec1 f p #
(Monoid a, Monoid b, Monoid c) => Monoid (a, b, c)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: (a, b, c) # mappend :: (a, b, c) -> (a, b, c) -> (a, b, c) # mconcat :: [(a, b, c)] -> (a, b, c) #
Monoid a => Monoid (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods mempty :: Const a b # mappend :: Const a b -> Const a b -> Const a b # mconcat :: [Const a b] -> Const a b #
(Applicative f, Monoid a) => Monoid (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods mempty :: Ap f a # mappend :: Ap f a -> Ap f a -> Ap f a # mconcat :: [Ap f a] -> Ap f a #
Alternative f => Monoid (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods mempty :: Alt f a # mappend :: Alt f a -> Alt f a -> Alt f a # mconcat :: [Alt f a] -> Alt f a #
Monoid c => Monoid (K1 i c p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods mempty :: K1 i c p # mappend :: K1 i c p -> K1 i c p -> K1 i c p # mconcat :: [K1 i c p] -> K1 i c p #
(Monoid (f p), Monoid (g p)) => Monoid ((f :*: g) p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods mempty :: (f :: g) p # mappend :: (f :: g) p -> (f :: g) p -> (f :: g) p # mconcat :: [(f :: g) p] -> (f :: g) p #
(Monoid a, Monoid b, Monoid c, Monoid d) => Monoid (a, b, c, d)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: (a, b, c, d) # mappend :: (a, b, c, d) -> (a, b, c, d) -> (a, b, c, d) # mconcat :: [(a, b, c, d)] -> (a, b, c, d) #
Monoid (f p) => Monoid (M1 i c f p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods mempty :: M1 i c f p # mappend :: M1 i c f p -> M1 i c f p -> M1 i c f p # mconcat :: [M1 i c f p] -> M1 i c f p #
Monoid (f (g p)) => Monoid ((f :.: g) p)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods mempty :: (f :.: g) p # mappend :: (f :.: g) p -> (f :.: g) p -> (f :.: g) p # mconcat :: [(f :.: g) p] -> (f :.: g) p #
(Monoid a, Monoid b, Monoid c, Monoid d, Monoid e) => Monoid (a, b, c, d, e)	Since: base-2.1
Instance details Defined in GHC.Base Methods mempty :: (a, b, c, d, e) # mappend :: (a, b, c, d, e) -> (a, b, c, d, e) -> (a, b, c, d, e) # mconcat :: [(a, b, c, d, e)] -> (a, b, c, d, e) #

Functor

newtype Const a (b :: k) #

The Const functor.

Constructors

Const
Fields getConst :: a

Instances

Instances details

Generic1 (Const a :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Associated Types type Rep1 (Const a) :: k -> Type # Methods from1 :: forall (a0 :: k0). Const a a0 -> Rep1 (Const a) a0 # to1 :: forall (a0 :: k0). Rep1 (Const a) a0 -> Const a a0 #
Bitraversable (Const :: Type -> Type -> Type)	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Const a b -> f (Const c d) #
Bifoldable (Const :: Type -> Type -> Type)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => Const m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Const a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Const a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Const a b -> c #
Bifunctor (Const :: Type -> Type -> Type)	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> Const a c -> Const b d # first :: (a -> b) -> Const a c -> Const b c # second :: (b -> c) -> Const a b -> Const a c #
Eq2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Const a c -> Const b d -> Bool #
Ord2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Const a c -> Const b d -> Ordering #
Read2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Const a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Const a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Const a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Const a b] #
Show2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Const a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Const a b] -> ShowS #
Functor (Const m :: Type -> Type)	Since: base-2.1
Instance details Defined in Data.Functor.Const Methods fmap :: (a -> b) -> Const m a -> Const m b # (<$) :: a -> Const m b -> Const m a #
Monoid m => Applicative (Const m :: Type -> Type)	Since: base-2.0.1
Instance details Defined in Data.Functor.Const Methods pure :: a -> Const m a # (<>) :: Const m (a -> b) -> Const m a -> Const m b # liftA2 :: (a -> b -> c) -> Const m a -> Const m b -> Const m c # (>) :: Const m a -> Const m b -> Const m b # (<*) :: Const m a -> Const m b -> Const m a #
Foldable (Const m :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Functor.Const Methods fold :: Monoid m0 => Const m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldr :: (a -> b -> b) -> b -> Const m a -> b # foldr' :: (a -> b -> b) -> b -> Const m a -> b # foldl :: (b -> a -> b) -> b -> Const m a -> b # foldl' :: (b -> a -> b) -> b -> Const m a -> b # foldr1 :: (a -> a -> a) -> Const m a -> a # foldl1 :: (a -> a -> a) -> Const m a -> a # toList :: Const m a -> [a] # null :: Const m a -> Bool # length :: Const m a -> Int # elem :: Eq a => a -> Const m a -> Bool # maximum :: Ord a => Const m a -> a # minimum :: Ord a => Const m a -> a # sum :: Num a => Const m a -> a # product :: Num a => Const m a -> a #
Traversable (Const m :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Const m a -> f (Const m b) # sequenceA :: Applicative f => Const m (f a) -> f (Const m a) # mapM :: Monad m0 => (a -> m0 b) -> Const m a -> m0 (Const m b) # sequence :: Monad m0 => Const m (m0 a) -> m0 (Const m a) #
Contravariant (Const a :: Type -> Type)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a0 -> b) -> Const a b -> Const a a0 # (>$) :: b -> Const a b -> Const a a0 #
Eq a => Eq1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a0 -> b -> Bool) -> Const a a0 -> Const a b -> Bool #
Ord a => Ord1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a0 -> b -> Ordering) -> Const a a0 -> Const a b -> Ordering #
Read a => Read1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Const a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Const a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Const a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Const a a0] #
Show a => Show1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> Const a a0 -> ShowS # liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [Const a a0] -> ShowS #
Bounded a => Bounded (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods minBound :: Const a b # maxBound :: Const a b #
Enum a => Enum (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods succ :: Const a b -> Const a b # pred :: Const a b -> Const a b # toEnum :: Int -> Const a b # fromEnum :: Const a b -> Int # enumFrom :: Const a b -> [Const a b] # enumFromThen :: Const a b -> Const a b -> [Const a b] # enumFromTo :: Const a b -> Const a b -> [Const a b] # enumFromThenTo :: Const a b -> Const a b -> Const a b -> [Const a b] #
Eq a => Eq (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (==) :: Const a b -> Const a b -> Bool # (/=) :: Const a b -> Const a b -> Bool #
Floating a => Floating (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods pi :: Const a b # exp :: Const a b -> Const a b # log :: Const a b -> Const a b # sqrt :: Const a b -> Const a b # (**) :: Const a b -> Const a b -> Const a b # logBase :: Const a b -> Const a b -> Const a b # sin :: Const a b -> Const a b # cos :: Const a b -> Const a b # tan :: Const a b -> Const a b # asin :: Const a b -> Const a b # acos :: Const a b -> Const a b # atan :: Const a b -> Const a b # sinh :: Const a b -> Const a b # cosh :: Const a b -> Const a b # tanh :: Const a b -> Const a b # asinh :: Const a b -> Const a b # acosh :: Const a b -> Const a b # atanh :: Const a b -> Const a b # log1p :: Const a b -> Const a b # expm1 :: Const a b -> Const a b # log1pexp :: Const a b -> Const a b # log1mexp :: Const a b -> Const a b #
Fractional a => Fractional (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (/) :: Const a b -> Const a b -> Const a b # recip :: Const a b -> Const a b # fromRational :: Rational -> Const a b #
Integral a => Integral (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods quot :: Const a b -> Const a b -> Const a b # rem :: Const a b -> Const a b -> Const a b # div :: Const a b -> Const a b -> Const a b # mod :: Const a b -> Const a b -> Const a b # quotRem :: Const a b -> Const a b -> (Const a b, Const a b) # divMod :: Const a b -> Const a b -> (Const a b, Const a b) # toInteger :: Const a b -> Integer #
Num a => Num (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (+) :: Const a b -> Const a b -> Const a b # (-) :: Const a b -> Const a b -> Const a b # (*) :: Const a b -> Const a b -> Const a b # negate :: Const a b -> Const a b # abs :: Const a b -> Const a b # signum :: Const a b -> Const a b # fromInteger :: Integer -> Const a b #
Ord a => Ord (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods compare :: Const a b -> Const a b -> Ordering # (<) :: Const a b -> Const a b -> Bool # (<=) :: Const a b -> Const a b -> Bool # (>) :: Const a b -> Const a b -> Bool # (>=) :: Const a b -> Const a b -> Bool # max :: Const a b -> Const a b -> Const a b # min :: Const a b -> Const a b -> Const a b #
Read a => Read (Const a b)	This instance would be equivalent to the derived instances of the `Const` newtype if the `getConst` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Const Methods readsPrec :: Int -> ReadS (Const a b) # readList :: ReadS [Const a b] # readPrec :: ReadPrec (Const a b) # readListPrec :: ReadPrec [Const a b] #
Real a => Real (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods toRational :: Const a b -> Rational #
RealFloat a => RealFloat (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods floatRadix :: Const a b -> Integer # floatDigits :: Const a b -> Int # floatRange :: Const a b -> (Int, Int) # decodeFloat :: Const a b -> (Integer, Int) # encodeFloat :: Integer -> Int -> Const a b # exponent :: Const a b -> Int # significand :: Const a b -> Const a b # scaleFloat :: Int -> Const a b -> Const a b # isNaN :: Const a b -> Bool # isInfinite :: Const a b -> Bool # isDenormalized :: Const a b -> Bool # isNegativeZero :: Const a b -> Bool # isIEEE :: Const a b -> Bool # atan2 :: Const a b -> Const a b -> Const a b #
RealFrac a => RealFrac (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods properFraction :: Integral b0 => Const a b -> (b0, Const a b) # truncate :: Integral b0 => Const a b -> b0 # round :: Integral b0 => Const a b -> b0 # ceiling :: Integral b0 => Const a b -> b0 # floor :: Integral b0 => Const a b -> b0 #
Show a => Show (Const a b)	This instance would be equivalent to the derived instances of the `Const` newtype if the `getConst` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Const Methods showsPrec :: Int -> Const a b -> ShowS # show :: Const a b -> String # showList :: [Const a b] -> ShowS #
Ix a => Ix (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods range :: (Const a b, Const a b) -> [Const a b] # index :: (Const a b, Const a b) -> Const a b -> Int # unsafeIndex :: (Const a b, Const a b) -> Const a b -> Int # inRange :: (Const a b, Const a b) -> Const a b -> Bool # rangeSize :: (Const a b, Const a b) -> Int # unsafeRangeSize :: (Const a b, Const a b) -> Int #
IsString a => IsString (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.String Methods fromString :: String -> Const a b #
Generic (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Associated Types type Rep (Const a b) :: Type -> Type # Methods from :: Const a b -> Rep (Const a b) x # to :: Rep (Const a b) x -> Const a b #
Semigroup a => Semigroup (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (<>) :: Const a b -> Const a b -> Const a b # sconcat :: NonEmpty (Const a b) -> Const a b # stimes :: Integral b0 => b0 -> Const a b -> Const a b #
Monoid a => Monoid (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods mempty :: Const a b # mappend :: Const a b -> Const a b -> Const a b # mconcat :: [Const a b] -> Const a b #
Storable a => Storable (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods sizeOf :: Const a b -> Int # alignment :: Const a b -> Int # peekElemOff :: Ptr (Const a b) -> Int -> IO (Const a b) # pokeElemOff :: Ptr (Const a b) -> Int -> Const a b -> IO () # peekByteOff :: Ptr b0 -> Int -> IO (Const a b) # pokeByteOff :: Ptr b0 -> Int -> Const a b -> IO () # peek :: Ptr (Const a b) -> IO (Const a b) # poke :: Ptr (Const a b) -> Const a b -> IO () #
Bits a => Bits (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (.&.) :: Const a b -> Const a b -> Const a b # (.\|.) :: Const a b -> Const a b -> Const a b # xor :: Const a b -> Const a b -> Const a b # complement :: Const a b -> Const a b # shift :: Const a b -> Int -> Const a b # rotate :: Const a b -> Int -> Const a b # zeroBits :: Const a b # bit :: Int -> Const a b # setBit :: Const a b -> Int -> Const a b # clearBit :: Const a b -> Int -> Const a b # complementBit :: Const a b -> Int -> Const a b # testBit :: Const a b -> Int -> Bool # bitSizeMaybe :: Const a b -> Maybe Int # bitSize :: Const a b -> Int # isSigned :: Const a b -> Bool # shiftL :: Const a b -> Int -> Const a b # unsafeShiftL :: Const a b -> Int -> Const a b # shiftR :: Const a b -> Int -> Const a b # unsafeShiftR :: Const a b -> Int -> Const a b # rotateL :: Const a b -> Int -> Const a b # rotateR :: Const a b -> Int -> Const a b # popCount :: Const a b -> Int #
FiniteBits a => FiniteBits (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods finiteBitSize :: Const a b -> Int # countLeadingZeros :: Const a b -> Int # countTrailingZeros :: Const a b -> Int #
type Rep1 (Const a :: k -> Type)
Instance details Defined in Data.Functor.Const type Rep1 (Const a :: k -> Type) = D1 ('MetaData "Const" "Data.Functor.Const" "base" 'True) (C1 ('MetaCons "Const" 'PrefixI 'True) (S1 ('MetaSel ('Just "getConst") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
type Rep (Const a b)
Instance details Defined in Data.Functor.Const type Rep (Const a b) = D1 ('MetaData "Const" "Data.Functor.Const" "base" 'True) (C1 ('MetaCons "Const" 'PrefixI 'True) (S1 ('MetaSel ('Just "getConst") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))

(<&>) :: Functor f => f a -> (a -> b) -> f b infixl 1 #

Flipped version of <$>.

(<&>) = flip fmap

Examples

Expand

Apply (+1) to a list, a Just and a Right:

>>> Just 2 <&> (+1)
Just 3

>>> [1,2,3] <&> (+1)
[2,3,4]

>>> Right 3 <&> (+1)
Right 4

Since: base-4.11.0.0

(<$) :: Functor f => a -> f b -> f a infixl 4 #

Replace all locations in the input with the same value. The default definition is fmap . const, but this may be overridden with a more efficient version.

Using ApplicativeDo: 'a <$ bs' can be understood as the do expression

do bs
   pure a

with an inferred Functor constraint.

(<$>) :: Functor f => (a -> b) -> f a -> f b infixl 4 #

An infix synonym for fmap.

The name of this operator is an allusion to $. Note the similarities between their types:

 ($)  ::              (a -> b) ->   a ->   b
(<$>) :: Functor f => (a -> b) -> f a -> f b

Whereas $ is function application, <$> is function application lifted over a Functor.

Examples

Expand

Convert from a Maybe Int to a Maybe String using show:

>>> show <$> Nothing
Nothing
>>> show <$> Just 3
Just "3"

Convert from an Either Int Int to an Either Int String using show:

>>> show <$> Left 17
Left 17
>>> show <$> Right 17
Right "17"

Double each element of a list:

>>> (*2) <$> [1,2,3]
[2,4,6]

Apply even to the second element of a pair:

>>> even <$> (2,2)
(2,True)

($>) :: Functor f => f a -> b -> f b infixl 4 #

Flipped version of <$.

Using ApplicativeDo: 'as $> b' can be understood as the do expression

do as
   pure b

with an inferred Functor constraint.

Examples

Expand

Replace the contents of a Maybe Int with a constant String:

>>> Nothing $> "foo"
Nothing
>>> Just 90210 $> "foo"
Just "foo"

Replace the contents of an Either Int Int with a constant String, resulting in an Either Int String:

>>> Left 8675309 $> "foo"
Left 8675309
>>> Right 8675309 $> "foo"
Right "foo"

Replace each element of a list with a constant String:

>>> [1,2,3] $> "foo"
["foo","foo","foo"]

Replace the second element of a pair with a constant String:

>>> (1,2) $> "foo"
(1,"foo")

Since: base-4.7.0.0

fmap :: Functor f => (a -> b) -> f a -> f b #

Using ApplicativeDo: 'fmap f as' can be understood as the do expression

do a <- as
   pure (f a)

with an inferred Functor constraint.

newtype Identity a #

Identity functor and monad. (a non-strict monad)

Since: base-4.8.0.0

Constructors

Identity
Fields runIdentity :: a

Instances

Instances details

Monad Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods (>>=) :: Identity a -> (a -> Identity b) -> Identity b # (>>) :: Identity a -> Identity b -> Identity b # return :: a -> Identity a #
Functor Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods fmap :: (a -> b) -> Identity a -> Identity b # (<$) :: a -> Identity b -> Identity a #
MonadFix Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods mfix :: (a -> Identity a) -> Identity a #
Applicative Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods pure :: a -> Identity a # (<>) :: Identity (a -> b) -> Identity a -> Identity b # liftA2 :: (a -> b -> c) -> Identity a -> Identity b -> Identity c # (>) :: Identity a -> Identity b -> Identity b # (<*) :: Identity a -> Identity b -> Identity a #
Foldable Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods fold :: Monoid m => Identity m -> m # foldMap :: Monoid m => (a -> m) -> Identity a -> m # foldMap' :: Monoid m => (a -> m) -> Identity a -> m # foldr :: (a -> b -> b) -> b -> Identity a -> b # foldr' :: (a -> b -> b) -> b -> Identity a -> b # foldl :: (b -> a -> b) -> b -> Identity a -> b # foldl' :: (b -> a -> b) -> b -> Identity a -> b # foldr1 :: (a -> a -> a) -> Identity a -> a # foldl1 :: (a -> a -> a) -> Identity a -> a # toList :: Identity a -> [a] # null :: Identity a -> Bool # length :: Identity a -> Int # elem :: Eq a => a -> Identity a -> Bool # maximum :: Ord a => Identity a -> a # minimum :: Ord a => Identity a -> a # sum :: Num a => Identity a -> a # product :: Num a => Identity a -> a #
Traversable Identity	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Identity a -> f (Identity b) # sequenceA :: Applicative f => Identity (f a) -> f (Identity a) # mapM :: Monad m => (a -> m b) -> Identity a -> m (Identity b) # sequence :: Monad m => Identity (m a) -> m (Identity a) #
Eq1 Identity	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> Identity a -> Identity b -> Bool #
Ord1 Identity	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> Identity a -> Identity b -> Ordering #
Read1 Identity	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Identity a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Identity a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Identity a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Identity a] #
Show1 Identity	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Identity a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Identity a] -> ShowS #
Bounded a => Bounded (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods minBound :: Identity a # maxBound :: Identity a #
Enum a => Enum (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods succ :: Identity a -> Identity a # pred :: Identity a -> Identity a # toEnum :: Int -> Identity a # fromEnum :: Identity a -> Int # enumFrom :: Identity a -> [Identity a] # enumFromThen :: Identity a -> Identity a -> [Identity a] # enumFromTo :: Identity a -> Identity a -> [Identity a] # enumFromThenTo :: Identity a -> Identity a -> Identity a -> [Identity a] #
Eq a => Eq (Identity a)	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods (==) :: Identity a -> Identity a -> Bool # (/=) :: Identity a -> Identity a -> Bool #
Floating a => Floating (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods pi :: Identity a # exp :: Identity a -> Identity a # log :: Identity a -> Identity a # sqrt :: Identity a -> Identity a # (**) :: Identity a -> Identity a -> Identity a # logBase :: Identity a -> Identity a -> Identity a # sin :: Identity a -> Identity a # cos :: Identity a -> Identity a # tan :: Identity a -> Identity a # asin :: Identity a -> Identity a # acos :: Identity a -> Identity a # atan :: Identity a -> Identity a # sinh :: Identity a -> Identity a # cosh :: Identity a -> Identity a # tanh :: Identity a -> Identity a # asinh :: Identity a -> Identity a # acosh :: Identity a -> Identity a # atanh :: Identity a -> Identity a # log1p :: Identity a -> Identity a # expm1 :: Identity a -> Identity a # log1pexp :: Identity a -> Identity a # log1mexp :: Identity a -> Identity a #
Fractional a => Fractional (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods (/) :: Identity a -> Identity a -> Identity a # recip :: Identity a -> Identity a # fromRational :: Rational -> Identity a #
Integral a => Integral (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods quot :: Identity a -> Identity a -> Identity a # rem :: Identity a -> Identity a -> Identity a # div :: Identity a -> Identity a -> Identity a # mod :: Identity a -> Identity a -> Identity a # quotRem :: Identity a -> Identity a -> (Identity a, Identity a) # divMod :: Identity a -> Identity a -> (Identity a, Identity a) # toInteger :: Identity a -> Integer #
Num a => Num (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods (+) :: Identity a -> Identity a -> Identity a # (-) :: Identity a -> Identity a -> Identity a # (*) :: Identity a -> Identity a -> Identity a # negate :: Identity a -> Identity a # abs :: Identity a -> Identity a # signum :: Identity a -> Identity a # fromInteger :: Integer -> Identity a #
Ord a => Ord (Identity a)	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods compare :: Identity a -> Identity a -> Ordering # (<) :: Identity a -> Identity a -> Bool # (<=) :: Identity a -> Identity a -> Bool # (>) :: Identity a -> Identity a -> Bool # (>=) :: Identity a -> Identity a -> Bool # max :: Identity a -> Identity a -> Identity a # min :: Identity a -> Identity a -> Identity a #
Read a => Read (Identity a)	This instance would be equivalent to the derived instances of the `Identity` newtype if the `runIdentity` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods readsPrec :: Int -> ReadS (Identity a) # readList :: ReadS [Identity a] # readPrec :: ReadPrec (Identity a) # readListPrec :: ReadPrec [Identity a] #
Real a => Real (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods toRational :: Identity a -> Rational #
RealFloat a => RealFloat (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods floatRadix :: Identity a -> Integer # floatDigits :: Identity a -> Int # floatRange :: Identity a -> (Int, Int) # decodeFloat :: Identity a -> (Integer, Int) # encodeFloat :: Integer -> Int -> Identity a # exponent :: Identity a -> Int # significand :: Identity a -> Identity a # scaleFloat :: Int -> Identity a -> Identity a # isNaN :: Identity a -> Bool # isInfinite :: Identity a -> Bool # isDenormalized :: Identity a -> Bool # isNegativeZero :: Identity a -> Bool # isIEEE :: Identity a -> Bool # atan2 :: Identity a -> Identity a -> Identity a #
RealFrac a => RealFrac (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods properFraction :: Integral b => Identity a -> (b, Identity a) # truncate :: Integral b => Identity a -> b # round :: Integral b => Identity a -> b # ceiling :: Integral b => Identity a -> b # floor :: Integral b => Identity a -> b #
Show a => Show (Identity a)	This instance would be equivalent to the derived instances of the `Identity` newtype if the `runIdentity` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods showsPrec :: Int -> Identity a -> ShowS # show :: Identity a -> String # showList :: [Identity a] -> ShowS #
Ix a => Ix (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods range :: (Identity a, Identity a) -> [Identity a] # index :: (Identity a, Identity a) -> Identity a -> Int # unsafeIndex :: (Identity a, Identity a) -> Identity a -> Int # inRange :: (Identity a, Identity a) -> Identity a -> Bool # rangeSize :: (Identity a, Identity a) -> Int # unsafeRangeSize :: (Identity a, Identity a) -> Int #
IsString a => IsString (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.String Methods fromString :: String -> Identity a #
Generic (Identity a)	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Associated Types type Rep (Identity a) :: Type -> Type # Methods from :: Identity a -> Rep (Identity a) x # to :: Rep (Identity a) x -> Identity a #
Semigroup a => Semigroup (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods (<>) :: Identity a -> Identity a -> Identity a # sconcat :: NonEmpty (Identity a) -> Identity a # stimes :: Integral b => b -> Identity a -> Identity a #
Monoid a => Monoid (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods mempty :: Identity a # mappend :: Identity a -> Identity a -> Identity a # mconcat :: [Identity a] -> Identity a #
Storable a => Storable (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods sizeOf :: Identity a -> Int # alignment :: Identity a -> Int # peekElemOff :: Ptr (Identity a) -> Int -> IO (Identity a) # pokeElemOff :: Ptr (Identity a) -> Int -> Identity a -> IO () # peekByteOff :: Ptr b -> Int -> IO (Identity a) # pokeByteOff :: Ptr b -> Int -> Identity a -> IO () # peek :: Ptr (Identity a) -> IO (Identity a) # poke :: Ptr (Identity a) -> Identity a -> IO () #
Bits a => Bits (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods (.&.) :: Identity a -> Identity a -> Identity a # (.\|.) :: Identity a -> Identity a -> Identity a # xor :: Identity a -> Identity a -> Identity a # complement :: Identity a -> Identity a # shift :: Identity a -> Int -> Identity a # rotate :: Identity a -> Int -> Identity a # zeroBits :: Identity a # bit :: Int -> Identity a # setBit :: Identity a -> Int -> Identity a # clearBit :: Identity a -> Int -> Identity a # complementBit :: Identity a -> Int -> Identity a # testBit :: Identity a -> Int -> Bool # bitSizeMaybe :: Identity a -> Maybe Int # bitSize :: Identity a -> Int # isSigned :: Identity a -> Bool # shiftL :: Identity a -> Int -> Identity a # unsafeShiftL :: Identity a -> Int -> Identity a # shiftR :: Identity a -> Int -> Identity a # unsafeShiftR :: Identity a -> Int -> Identity a # rotateL :: Identity a -> Int -> Identity a # rotateR :: Identity a -> Int -> Identity a # popCount :: Identity a -> Int #
FiniteBits a => FiniteBits (Identity a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods finiteBitSize :: Identity a -> Int # countLeadingZeros :: Identity a -> Int # countTrailingZeros :: Identity a -> Int #
Generic1 Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Associated Types type Rep1 Identity :: k -> Type # Methods from1 :: forall (a :: k). Identity a -> Rep1 Identity a # to1 :: forall (a :: k). Rep1 Identity a -> Identity a #
type Rep (Identity a)
Instance details Defined in Data.Functor.Identity type Rep (Identity a) = D1 ('MetaData "Identity" "Data.Functor.Identity" "base" 'True) (C1 ('MetaCons "Identity" 'PrefixI 'True) (S1 ('MetaSel ('Just "runIdentity") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
type Rep1 Identity
Instance details Defined in Data.Functor.Identity type Rep1 Identity = D1 ('MetaData "Identity" "Data.Functor.Identity" "base" 'True) (C1 ('MetaCons "Identity" 'PrefixI 'True) (S1 ('MetaSel ('Just "runIdentity") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

void :: Functor f => f a -> f () #

void value discards or ignores the result of evaluation, such as the return value of an IO action.

Using ApplicativeDo: 'void as' can be understood as the do expression

do as
   pure ()

with an inferred Functor constraint.

Examples

Expand

Replace the contents of a Maybe Int with unit:

>>> void Nothing
Nothing
>>> void (Just 3)
Just ()

Replace the contents of an Either Int Int with unit, resulting in an Either Int ():

>>> void (Left 8675309)
Left 8675309
>>> void (Right 8675309)
Right ()

Replace every element of a list with unit:

>>> void [1,2,3]
[(),(),()]

Replace the second element of a pair with unit:

>>> void (1,2)
(1,())

Discard the result of an IO action:

>>> mapM print [1,2]
1
2
[(),()]
>>> void $ mapM print [1,2]
1
2

Contravariant

class Contravariant (f :: Type -> Type) where #

The class of contravariant functors.

Whereas in Haskell, one can think of a Functor as containing or producing values, a contravariant functor is a functor that can be thought of as consuming values.

As an example, consider the type of predicate functions a -> Bool. One such predicate might be negative x = x < 0, which classifies integers as to whether they are negative. However, given this predicate, we can re-use it in other situations, providing we have a way to map values to integers. For instance, we can use the negative predicate on a person's bank balance to work out if they are currently overdrawn:

newtype Predicate a = Predicate { getPredicate :: a -> Bool }

instance Contravariant Predicate where
  contramap f (Predicate p) = Predicate (p . f)
                                         |   `- First, map the input...
                                         `----- then apply the predicate.

overdrawn :: Predicate Person
overdrawn = contramap personBankBalance negative

Any instance should be subject to the following laws:

Identity: contramap id = id
Composition: contramap (g . f) = contramap f . contramap g

Note, that the second law follows from the free theorem of the type of contramap and the first law, so you need only check that the former condition holds.

Minimal complete definition

contramap

Methods

contramap :: (a -> b) -> f b -> f a #

(>$) :: b -> f b -> f a infixl 4 #

Replace all locations in the output with the same value. The default definition is contramap . const, but this may be overridden with a more efficient version.

Instances

Instances details

Contravariant Predicate	A `Predicate` is a `Contravariant` `Functor`, because `contramap` can apply its function argument to the input of the predicate.
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Predicate b -> Predicate a # (>$) :: b -> Predicate b -> Predicate a #
Contravariant Comparison	A `Comparison` is a `Contravariant` `Functor`, because `contramap` can apply its function argument to each input of the comparison function.
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Comparison b -> Comparison a # (>$) :: b -> Comparison b -> Comparison a #
Contravariant Equivalence	Equivalence relations are `Contravariant`, because you can apply the contramapped function to each input to the equivalence relation.
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Equivalence b -> Equivalence a # (>$) :: b -> Equivalence b -> Equivalence a #
Contravariant (V1 :: Type -> Type)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> V1 b -> V1 a # (>$) :: b -> V1 b -> V1 a #
Contravariant (U1 :: Type -> Type)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> U1 b -> U1 a # (>$) :: b -> U1 b -> U1 a #
Contravariant (Op a)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a0 -> b) -> Op a b -> Op a a0 # (>$) :: b -> Op a b -> Op a a0 #
Contravariant (Proxy :: Type -> Type)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Proxy b -> Proxy a # (>$) :: b -> Proxy b -> Proxy a #
Contravariant f => Contravariant (Rec1 f)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Rec1 f b -> Rec1 f a # (>$) :: b -> Rec1 f b -> Rec1 f a #
Contravariant (Const a :: Type -> Type)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a0 -> b) -> Const a b -> Const a a0 # (>$) :: b -> Const a b -> Const a a0 #
Contravariant f => Contravariant (Alt f)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Alt f b -> Alt f a # (>$) :: b -> Alt f b -> Alt f a #
Contravariant m => Contravariant (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods contramap :: (a -> b) -> ErrorT e m b -> ErrorT e m a # (>$) :: b -> ErrorT e m b -> ErrorT e m a #
Contravariant (K1 i c :: Type -> Type)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> K1 i c b -> K1 i c a # (>$) :: b -> K1 i c b -> K1 i c a #
(Contravariant f, Contravariant g) => Contravariant (f :+: g)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> (f :+: g) b -> (f :+: g) a # (>$) :: b -> (f :+: g) b -> (f :+: g) a #
(Contravariant f, Contravariant g) => Contravariant (f :*: g)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> (f :: g) b -> (f :: g) a # (>$) :: b -> (f :: g) b -> (f :: g) a #
(Contravariant f, Contravariant g) => Contravariant (Product f g)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Product f g b -> Product f g a # (>$) :: b -> Product f g b -> Product f g a #
(Contravariant f, Contravariant g) => Contravariant (Sum f g)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Sum f g b -> Sum f g a # (>$) :: b -> Sum f g b -> Sum f g a #
Contravariant f => Contravariant (M1 i c f)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> M1 i c f b -> M1 i c f a # (>$) :: b -> M1 i c f b -> M1 i c f a #
(Functor f, Contravariant g) => Contravariant (f :.: g)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> (f :.: g) b -> (f :.: g) a # (>$) :: b -> (f :.: g) b -> (f :.: g) a #
(Functor f, Contravariant g) => Contravariant (Compose f g)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Compose f g b -> Compose f g a # (>$) :: b -> Compose f g b -> Compose f g a #

($<) :: Contravariant f => f b -> b -> f a infixl 4 #

This is >$ with its arguments flipped.

(>$<) :: Contravariant f => (a -> b) -> f b -> f a infixl 4 #

This is an infix alias for contramap.

(>$$<) :: Contravariant f => f b -> (a -> b) -> f a infixl 4 #

This is an infix version of contramap with the arguments flipped.

Foldable

class Foldable (t :: Type -> Type) where #

Data structures that can be folded.

For example, given a data type

data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)

a suitable instance would be

instance Foldable Tree where
   foldMap f Empty = mempty
   foldMap f (Leaf x) = f x
   foldMap f (Node l k r) = foldMap f l `mappend` f k `mappend` foldMap f r

This is suitable even for abstract types, as the monoid is assumed to satisfy the monoid laws. Alternatively, one could define foldr:

instance Foldable Tree where
   foldr f z Empty = z
   foldr f z (Leaf x) = f x z
   foldr f z (Node l k r) = foldr f (f k (foldr f z r)) l

Foldable instances are expected to satisfy the following laws:

foldr f z t = appEndo (foldMap (Endo . f) t ) z

foldl f z t = appEndo (getDual (foldMap (Dual . Endo . flip f) t)) z

fold = foldMap id

length = getSum . foldMap (Sum . const  1)

sum, product, maximum, and minimum should all be essentially equivalent to foldMap forms, such as

sum = getSum . foldMap Sum

but may be less defined.

If the type is also a Functor instance, it should satisfy

foldMap f = fold . fmap f

which implies that

foldMap f . fmap g = foldMap (f . g)

Minimal complete definition

foldMap | foldr

Methods

fold :: Monoid m => t m -> m #

Combine the elements of a structure using a monoid.

foldMap :: Monoid m => (a -> m) -> t a -> m #

Map each element of the structure to a monoid, and combine the results.

foldr :: (a -> b -> b) -> b -> t a -> b #

Right-associative fold of a structure.

In the case of lists, foldr, when applied to a binary operator, a starting value (typically the right-identity of the operator), and a list, reduces the list using the binary operator, from right to left:

foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)

Note that, since the head of the resulting expression is produced by an application of the operator to the first element of the list, foldr can produce a terminating expression from an infinite list.

For a general Foldable structure this should be semantically identical to,

foldr f z = foldr f z . toList

foldr' :: (a -> b -> b) -> b -> t a -> b #

Right-associative fold of a structure, but with strict application of the operator.

Since: base-4.6.0.0

foldl :: (b -> a -> b) -> b -> t a -> b #

Left-associative fold of a structure.

In the case of lists, foldl, when applied to a binary operator, a starting value (typically the left-identity of the operator), and a list, reduces the list using the binary operator, from left to right:

foldl f z [x1, x2, ..., xn] == (...((z `f` x1) `f` x2) `f`...) `f` xn

Note that to produce the outermost application of the operator the entire input list must be traversed. This means that foldl' will diverge if given an infinite list.

Also note that if you want an efficient left-fold, you probably want to use foldl' instead of foldl. The reason for this is that latter does not force the "inner" results (e.g. z `f` x1 in the above example) before applying them to the operator (e.g. to (`f` x2)). This results in a thunk chain $\mathcal{O}(n)$ elements long, which then must be evaluated from the outside-in.

For a general Foldable structure this should be semantically identical to,

foldl f z = foldl f z . toList

foldl' :: (b -> a -> b) -> b -> t a -> b #

Left-associative fold of a structure but with strict application of the operator.

This ensures that each step of the fold is forced to weak head normal form before being applied, avoiding the collection of thunks that would otherwise occur. This is often what you want to strictly reduce a finite list to a single, monolithic result (e.g. length).

For a general Foldable structure this should be semantically identical to,

foldl' f z = foldl' f z . toList

Since: base-4.6.0.0

toList :: t a -> [a] #

List of elements of a structure, from left to right.

Since: base-4.8.0.0

elem :: Eq a => a -> t a -> Bool infix 4 #

Does the element occur in the structure?

Since: base-4.8.0.0

sum :: Num a => t a -> a #

The sum function computes the sum of the numbers of a structure.

Since: base-4.8.0.0

product :: Num a => t a -> a #

The product function computes the product of the numbers of a structure.

Since: base-4.8.0.0

Instances

Instances details

Foldable []	Since: base-2.1
Instance details Defined in Data.Foldable Methods fold :: Monoid m => [m] -> m # foldMap :: Monoid m => (a -> m) -> [a] -> m # foldMap' :: Monoid m => (a -> m) -> [a] -> m # foldr :: (a -> b -> b) -> b -> [a] -> b # foldr' :: (a -> b -> b) -> b -> [a] -> b # foldl :: (b -> a -> b) -> b -> [a] -> b # foldl' :: (b -> a -> b) -> b -> [a] -> b # foldr1 :: (a -> a -> a) -> [a] -> a # foldl1 :: (a -> a -> a) -> [a] -> a # toList :: [a] -> [a] # null :: [a] -> Bool # length :: [a] -> Int # elem :: Eq a => a -> [a] -> Bool # maximum :: Ord a => [a] -> a # minimum :: Ord a => [a] -> a # sum :: Num a => [a] -> a # product :: Num a => [a] -> a #
Foldable Maybe	Since: base-2.1
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # toList :: Maybe a -> [a] # null :: Maybe a -> Bool # length :: Maybe a -> Int # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # sum :: Num a => Maybe a -> a # product :: Num a => Maybe a -> a #
Foldable Par1	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Par1 m -> m # foldMap :: Monoid m => (a -> m) -> Par1 a -> m # foldMap' :: Monoid m => (a -> m) -> Par1 a -> m # foldr :: (a -> b -> b) -> b -> Par1 a -> b # foldr' :: (a -> b -> b) -> b -> Par1 a -> b # foldl :: (b -> a -> b) -> b -> Par1 a -> b # foldl' :: (b -> a -> b) -> b -> Par1 a -> b # foldr1 :: (a -> a -> a) -> Par1 a -> a # foldl1 :: (a -> a -> a) -> Par1 a -> a # toList :: Par1 a -> [a] # null :: Par1 a -> Bool # length :: Par1 a -> Int # elem :: Eq a => a -> Par1 a -> Bool # maximum :: Ord a => Par1 a -> a # minimum :: Ord a => Par1 a -> a # sum :: Num a => Par1 a -> a # product :: Num a => Par1 a -> a #
Foldable Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => Min m -> m # foldMap :: Monoid m => (a -> m) -> Min a -> m # foldMap' :: Monoid m => (a -> m) -> Min a -> m # foldr :: (a -> b -> b) -> b -> Min a -> b # foldr' :: (a -> b -> b) -> b -> Min a -> b # foldl :: (b -> a -> b) -> b -> Min a -> b # foldl' :: (b -> a -> b) -> b -> Min a -> b # foldr1 :: (a -> a -> a) -> Min a -> a # foldl1 :: (a -> a -> a) -> Min a -> a # toList :: Min a -> [a] # null :: Min a -> Bool # length :: Min a -> Int # elem :: Eq a => a -> Min a -> Bool # maximum :: Ord a => Min a -> a # minimum :: Ord a => Min a -> a # sum :: Num a => Min a -> a # product :: Num a => Min a -> a #
Foldable Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => Max m -> m # foldMap :: Monoid m => (a -> m) -> Max a -> m # foldMap' :: Monoid m => (a -> m) -> Max a -> m # foldr :: (a -> b -> b) -> b -> Max a -> b # foldr' :: (a -> b -> b) -> b -> Max a -> b # foldl :: (b -> a -> b) -> b -> Max a -> b # foldl' :: (b -> a -> b) -> b -> Max a -> b # foldr1 :: (a -> a -> a) -> Max a -> a # foldl1 :: (a -> a -> a) -> Max a -> a # toList :: Max a -> [a] # null :: Max a -> Bool # length :: Max a -> Int # elem :: Eq a => a -> Max a -> Bool # maximum :: Ord a => Max a -> a # minimum :: Ord a => Max a -> a # sum :: Num a => Max a -> a # product :: Num a => Max a -> a #
Foldable First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # toList :: First a -> [a] # null :: First a -> Bool # length :: First a -> Int # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # sum :: Num a => First a -> a # product :: Num a => First a -> a #
Foldable Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # toList :: Last a -> [a] # null :: Last a -> Bool # length :: Last a -> Int # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # minimum :: Ord a => Last a -> a # sum :: Num a => Last a -> a # product :: Num a => Last a -> a #
Foldable Option	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => Option m -> m # foldMap :: Monoid m => (a -> m) -> Option a -> m # foldMap' :: Monoid m => (a -> m) -> Option a -> m # foldr :: (a -> b -> b) -> b -> Option a -> b # foldr' :: (a -> b -> b) -> b -> Option a -> b # foldl :: (b -> a -> b) -> b -> Option a -> b # foldl' :: (b -> a -> b) -> b -> Option a -> b # foldr1 :: (a -> a -> a) -> Option a -> a # foldl1 :: (a -> a -> a) -> Option a -> a # toList :: Option a -> [a] # null :: Option a -> Bool # length :: Option a -> Int # elem :: Eq a => a -> Option a -> Bool # maximum :: Ord a => Option a -> a # minimum :: Ord a => Option a -> a # sum :: Num a => Option a -> a # product :: Num a => Option a -> a #
Foldable ZipList	Since: base-4.9.0.0
Instance details Defined in Control.Applicative Methods fold :: Monoid m => ZipList m -> m # foldMap :: Monoid m => (a -> m) -> ZipList a -> m # foldMap' :: Monoid m => (a -> m) -> ZipList a -> m # foldr :: (a -> b -> b) -> b -> ZipList a -> b # foldr' :: (a -> b -> b) -> b -> ZipList a -> b # foldl :: (b -> a -> b) -> b -> ZipList a -> b # foldl' :: (b -> a -> b) -> b -> ZipList a -> b # foldr1 :: (a -> a -> a) -> ZipList a -> a # foldl1 :: (a -> a -> a) -> ZipList a -> a # toList :: ZipList a -> [a] # null :: ZipList a -> Bool # length :: ZipList a -> Int # elem :: Eq a => a -> ZipList a -> Bool # maximum :: Ord a => ZipList a -> a # minimum :: Ord a => ZipList a -> a # sum :: Num a => ZipList a -> a # product :: Num a => ZipList a -> a #
Foldable Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods fold :: Monoid m => Identity m -> m # foldMap :: Monoid m => (a -> m) -> Identity a -> m # foldMap' :: Monoid m => (a -> m) -> Identity a -> m # foldr :: (a -> b -> b) -> b -> Identity a -> b # foldr' :: (a -> b -> b) -> b -> Identity a -> b # foldl :: (b -> a -> b) -> b -> Identity a -> b # foldl' :: (b -> a -> b) -> b -> Identity a -> b # foldr1 :: (a -> a -> a) -> Identity a -> a # foldl1 :: (a -> a -> a) -> Identity a -> a # toList :: Identity a -> [a] # null :: Identity a -> Bool # length :: Identity a -> Int # elem :: Eq a => a -> Identity a -> Bool # maximum :: Ord a => Identity a -> a # minimum :: Ord a => Identity a -> a # sum :: Num a => Identity a -> a # product :: Num a => Identity a -> a #
Foldable First	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # toList :: First a -> [a] # null :: First a -> Bool # length :: First a -> Int # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # sum :: Num a => First a -> a # product :: Num a => First a -> a #
Foldable Last	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # toList :: Last a -> [a] # null :: Last a -> Bool # length :: Last a -> Int # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # minimum :: Ord a => Last a -> a # sum :: Num a => Last a -> a # product :: Num a => Last a -> a #
Foldable Dual	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Dual m -> m # foldMap :: Monoid m => (a -> m) -> Dual a -> m # foldMap' :: Monoid m => (a -> m) -> Dual a -> m # foldr :: (a -> b -> b) -> b -> Dual a -> b # foldr' :: (a -> b -> b) -> b -> Dual a -> b # foldl :: (b -> a -> b) -> b -> Dual a -> b # foldl' :: (b -> a -> b) -> b -> Dual a -> b # foldr1 :: (a -> a -> a) -> Dual a -> a # foldl1 :: (a -> a -> a) -> Dual a -> a # toList :: Dual a -> [a] # null :: Dual a -> Bool # length :: Dual a -> Int # elem :: Eq a => a -> Dual a -> Bool # maximum :: Ord a => Dual a -> a # minimum :: Ord a => Dual a -> a # sum :: Num a => Dual a -> a # product :: Num a => Dual a -> a #
Foldable Sum	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Sum m -> m # foldMap :: Monoid m => (a -> m) -> Sum a -> m # foldMap' :: Monoid m => (a -> m) -> Sum a -> m # foldr :: (a -> b -> b) -> b -> Sum a -> b # foldr' :: (a -> b -> b) -> b -> Sum a -> b # foldl :: (b -> a -> b) -> b -> Sum a -> b # foldl' :: (b -> a -> b) -> b -> Sum a -> b # foldr1 :: (a -> a -> a) -> Sum a -> a # foldl1 :: (a -> a -> a) -> Sum a -> a # toList :: Sum a -> [a] # null :: Sum a -> Bool # length :: Sum a -> Int # elem :: Eq a => a -> Sum a -> Bool # maximum :: Ord a => Sum a -> a # minimum :: Ord a => Sum a -> a # sum :: Num a => Sum a -> a # product :: Num a => Sum a -> a #
Foldable Product	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Product m -> m # foldMap :: Monoid m => (a -> m) -> Product a -> m # foldMap' :: Monoid m => (a -> m) -> Product a -> m # foldr :: (a -> b -> b) -> b -> Product a -> b # foldr' :: (a -> b -> b) -> b -> Product a -> b # foldl :: (b -> a -> b) -> b -> Product a -> b # foldl' :: (b -> a -> b) -> b -> Product a -> b # foldr1 :: (a -> a -> a) -> Product a -> a # foldl1 :: (a -> a -> a) -> Product a -> a # toList :: Product a -> [a] # null :: Product a -> Bool # length :: Product a -> Int # elem :: Eq a => a -> Product a -> Bool # maximum :: Ord a => Product a -> a # minimum :: Ord a => Product a -> a # sum :: Num a => Product a -> a # product :: Num a => Product a -> a #
Foldable Down	Since: base-4.12.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Down m -> m # foldMap :: Monoid m => (a -> m) -> Down a -> m # foldMap' :: Monoid m => (a -> m) -> Down a -> m # foldr :: (a -> b -> b) -> b -> Down a -> b # foldr' :: (a -> b -> b) -> b -> Down a -> b # foldl :: (b -> a -> b) -> b -> Down a -> b # foldl' :: (b -> a -> b) -> b -> Down a -> b # foldr1 :: (a -> a -> a) -> Down a -> a # foldl1 :: (a -> a -> a) -> Down a -> a # toList :: Down a -> [a] # null :: Down a -> Bool # length :: Down a -> Int # elem :: Eq a => a -> Down a -> Bool # maximum :: Ord a => Down a -> a # minimum :: Ord a => Down a -> a # sum :: Num a => Down a -> a # product :: Num a => Down a -> a #
Foldable NonEmpty	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => NonEmpty m -> m # foldMap :: Monoid m => (a -> m) -> NonEmpty a -> m # foldMap' :: Monoid m => (a -> m) -> NonEmpty a -> m # foldr :: (a -> b -> b) -> b -> NonEmpty a -> b # foldr' :: (a -> b -> b) -> b -> NonEmpty a -> b # foldl :: (b -> a -> b) -> b -> NonEmpty a -> b # foldl' :: (b -> a -> b) -> b -> NonEmpty a -> b # foldr1 :: (a -> a -> a) -> NonEmpty a -> a # foldl1 :: (a -> a -> a) -> NonEmpty a -> a # toList :: NonEmpty a -> [a] # null :: NonEmpty a -> Bool # length :: NonEmpty a -> Int # elem :: Eq a => a -> NonEmpty a -> Bool # maximum :: Ord a => NonEmpty a -> a # minimum :: Ord a => NonEmpty a -> a # sum :: Num a => NonEmpty a -> a # product :: Num a => NonEmpty a -> a #
Foldable Set	Folds in order of increasing key.
Instance details Defined in Data.Set.Internal Methods fold :: Monoid m => Set m -> m # foldMap :: Monoid m => (a -> m) -> Set a -> m # foldMap' :: Monoid m => (a -> m) -> Set a -> m # foldr :: (a -> b -> b) -> b -> Set a -> b # foldr' :: (a -> b -> b) -> b -> Set a -> b # foldl :: (b -> a -> b) -> b -> Set a -> b # foldl' :: (b -> a -> b) -> b -> Set a -> b # foldr1 :: (a -> a -> a) -> Set a -> a # foldl1 :: (a -> a -> a) -> Set a -> a # toList :: Set a -> [a] # null :: Set a -> Bool # length :: Set a -> Int # elem :: Eq a => a -> Set a -> Bool # maximum :: Ord a => Set a -> a # minimum :: Ord a => Set a -> a # sum :: Num a => Set a -> a # product :: Num a => Set a -> a #
Foldable (Either a)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Either a m -> m # foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # toList :: Either a a0 -> [a0] # null :: Either a a0 -> Bool # length :: Either a a0 -> Int # elem :: Eq a0 => a0 -> Either a a0 -> Bool # maximum :: Ord a0 => Either a a0 -> a0 # minimum :: Ord a0 => Either a a0 -> a0 # sum :: Num a0 => Either a a0 -> a0 # product :: Num a0 => Either a a0 -> a0 #
Foldable (V1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => V1 m -> m # foldMap :: Monoid m => (a -> m) -> V1 a -> m # foldMap' :: Monoid m => (a -> m) -> V1 a -> m # foldr :: (a -> b -> b) -> b -> V1 a -> b # foldr' :: (a -> b -> b) -> b -> V1 a -> b # foldl :: (b -> a -> b) -> b -> V1 a -> b # foldl' :: (b -> a -> b) -> b -> V1 a -> b # foldr1 :: (a -> a -> a) -> V1 a -> a # foldl1 :: (a -> a -> a) -> V1 a -> a # toList :: V1 a -> [a] # null :: V1 a -> Bool # length :: V1 a -> Int # elem :: Eq a => a -> V1 a -> Bool # maximum :: Ord a => V1 a -> a # minimum :: Ord a => V1 a -> a # sum :: Num a => V1 a -> a # product :: Num a => V1 a -> a #
Foldable (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => U1 m -> m # foldMap :: Monoid m => (a -> m) -> U1 a -> m # foldMap' :: Monoid m => (a -> m) -> U1 a -> m # foldr :: (a -> b -> b) -> b -> U1 a -> b # foldr' :: (a -> b -> b) -> b -> U1 a -> b # foldl :: (b -> a -> b) -> b -> U1 a -> b # foldl' :: (b -> a -> b) -> b -> U1 a -> b # foldr1 :: (a -> a -> a) -> U1 a -> a # foldl1 :: (a -> a -> a) -> U1 a -> a # toList :: U1 a -> [a] # null :: U1 a -> Bool # length :: U1 a -> Int # elem :: Eq a => a -> U1 a -> Bool # maximum :: Ord a => U1 a -> a # minimum :: Ord a => U1 a -> a # sum :: Num a => U1 a -> a # product :: Num a => U1 a -> a #
Foldable (UAddr :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UAddr m -> m # foldMap :: Monoid m => (a -> m) -> UAddr a -> m # foldMap' :: Monoid m => (a -> m) -> UAddr a -> m # foldr :: (a -> b -> b) -> b -> UAddr a -> b # foldr' :: (a -> b -> b) -> b -> UAddr a -> b # foldl :: (b -> a -> b) -> b -> UAddr a -> b # foldl' :: (b -> a -> b) -> b -> UAddr a -> b # foldr1 :: (a -> a -> a) -> UAddr a -> a # foldl1 :: (a -> a -> a) -> UAddr a -> a # toList :: UAddr a -> [a] # null :: UAddr a -> Bool # length :: UAddr a -> Int # elem :: Eq a => a -> UAddr a -> Bool # maximum :: Ord a => UAddr a -> a # minimum :: Ord a => UAddr a -> a # sum :: Num a => UAddr a -> a # product :: Num a => UAddr a -> a #
Foldable (UChar :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UChar m -> m # foldMap :: Monoid m => (a -> m) -> UChar a -> m # foldMap' :: Monoid m => (a -> m) -> UChar a -> m # foldr :: (a -> b -> b) -> b -> UChar a -> b # foldr' :: (a -> b -> b) -> b -> UChar a -> b # foldl :: (b -> a -> b) -> b -> UChar a -> b # foldl' :: (b -> a -> b) -> b -> UChar a -> b # foldr1 :: (a -> a -> a) -> UChar a -> a # foldl1 :: (a -> a -> a) -> UChar a -> a # toList :: UChar a -> [a] # null :: UChar a -> Bool # length :: UChar a -> Int # elem :: Eq a => a -> UChar a -> Bool # maximum :: Ord a => UChar a -> a # minimum :: Ord a => UChar a -> a # sum :: Num a => UChar a -> a # product :: Num a => UChar a -> a #
Foldable (UDouble :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UDouble m -> m # foldMap :: Monoid m => (a -> m) -> UDouble a -> m # foldMap' :: Monoid m => (a -> m) -> UDouble a -> m # foldr :: (a -> b -> b) -> b -> UDouble a -> b # foldr' :: (a -> b -> b) -> b -> UDouble a -> b # foldl :: (b -> a -> b) -> b -> UDouble a -> b # foldl' :: (b -> a -> b) -> b -> UDouble a -> b # foldr1 :: (a -> a -> a) -> UDouble a -> a # foldl1 :: (a -> a -> a) -> UDouble a -> a # toList :: UDouble a -> [a] # null :: UDouble a -> Bool # length :: UDouble a -> Int # elem :: Eq a => a -> UDouble a -> Bool # maximum :: Ord a => UDouble a -> a # minimum :: Ord a => UDouble a -> a # sum :: Num a => UDouble a -> a # product :: Num a => UDouble a -> a #
Foldable (UFloat :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UFloat m -> m # foldMap :: Monoid m => (a -> m) -> UFloat a -> m # foldMap' :: Monoid m => (a -> m) -> UFloat a -> m # foldr :: (a -> b -> b) -> b -> UFloat a -> b # foldr' :: (a -> b -> b) -> b -> UFloat a -> b # foldl :: (b -> a -> b) -> b -> UFloat a -> b # foldl' :: (b -> a -> b) -> b -> UFloat a -> b # foldr1 :: (a -> a -> a) -> UFloat a -> a # foldl1 :: (a -> a -> a) -> UFloat a -> a # toList :: UFloat a -> [a] # null :: UFloat a -> Bool # length :: UFloat a -> Int # elem :: Eq a => a -> UFloat a -> Bool # maximum :: Ord a => UFloat a -> a # minimum :: Ord a => UFloat a -> a # sum :: Num a => UFloat a -> a # product :: Num a => UFloat a -> a #
Foldable (UInt :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UInt m -> m # foldMap :: Monoid m => (a -> m) -> UInt a -> m # foldMap' :: Monoid m => (a -> m) -> UInt a -> m # foldr :: (a -> b -> b) -> b -> UInt a -> b # foldr' :: (a -> b -> b) -> b -> UInt a -> b # foldl :: (b -> a -> b) -> b -> UInt a -> b # foldl' :: (b -> a -> b) -> b -> UInt a -> b # foldr1 :: (a -> a -> a) -> UInt a -> a # foldl1 :: (a -> a -> a) -> UInt a -> a # toList :: UInt a -> [a] # null :: UInt a -> Bool # length :: UInt a -> Int # elem :: Eq a => a -> UInt a -> Bool # maximum :: Ord a => UInt a -> a # minimum :: Ord a => UInt a -> a # sum :: Num a => UInt a -> a # product :: Num a => UInt a -> a #
Foldable (UWord :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => UWord m -> m # foldMap :: Monoid m => (a -> m) -> UWord a -> m # foldMap' :: Monoid m => (a -> m) -> UWord a -> m # foldr :: (a -> b -> b) -> b -> UWord a -> b # foldr' :: (a -> b -> b) -> b -> UWord a -> b # foldl :: (b -> a -> b) -> b -> UWord a -> b # foldl' :: (b -> a -> b) -> b -> UWord a -> b # foldr1 :: (a -> a -> a) -> UWord a -> a # foldl1 :: (a -> a -> a) -> UWord a -> a # toList :: UWord a -> [a] # null :: UWord a -> Bool # length :: UWord a -> Int # elem :: Eq a => a -> UWord a -> Bool # maximum :: Ord a => UWord a -> a # minimum :: Ord a => UWord a -> a # sum :: Num a => UWord a -> a # product :: Num a => UWord a -> a #
Foldable ((,) a)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => (a, m) -> m # foldMap :: Monoid m => (a0 -> m) -> (a, a0) -> m # foldMap' :: Monoid m => (a0 -> m) -> (a, a0) -> m # foldr :: (a0 -> b -> b) -> b -> (a, a0) -> b # foldr' :: (a0 -> b -> b) -> b -> (a, a0) -> b # foldl :: (b -> a0 -> b) -> b -> (a, a0) -> b # foldl' :: (b -> a0 -> b) -> b -> (a, a0) -> b # foldr1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 # foldl1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 # toList :: (a, a0) -> [a0] # null :: (a, a0) -> Bool # length :: (a, a0) -> Int # elem :: Eq a0 => a0 -> (a, a0) -> Bool # maximum :: Ord a0 => (a, a0) -> a0 # minimum :: Ord a0 => (a, a0) -> a0 # sum :: Num a0 => (a, a0) -> a0 # product :: Num a0 => (a, a0) -> a0 #
Foldable (Array i)	Since: base-4.8.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Array i m -> m # foldMap :: Monoid m => (a -> m) -> Array i a -> m # foldMap' :: Monoid m => (a -> m) -> Array i a -> m # foldr :: (a -> b -> b) -> b -> Array i a -> b # foldr' :: (a -> b -> b) -> b -> Array i a -> b # foldl :: (b -> a -> b) -> b -> Array i a -> b # foldl' :: (b -> a -> b) -> b -> Array i a -> b # foldr1 :: (a -> a -> a) -> Array i a -> a # foldl1 :: (a -> a -> a) -> Array i a -> a # toList :: Array i a -> [a] # null :: Array i a -> Bool # length :: Array i a -> Int # elem :: Eq a => a -> Array i a -> Bool # maximum :: Ord a => Array i a -> a # minimum :: Ord a => Array i a -> a # sum :: Num a => Array i a -> a # product :: Num a => Array i a -> a #
Foldable (Arg a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fold :: Monoid m => Arg a m -> m # foldMap :: Monoid m => (a0 -> m) -> Arg a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Arg a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Arg a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Arg a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Arg a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Arg a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Arg a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Arg a a0 -> a0 # toList :: Arg a a0 -> [a0] # null :: Arg a a0 -> Bool # length :: Arg a a0 -> Int # elem :: Eq a0 => a0 -> Arg a a0 -> Bool # maximum :: Ord a0 => Arg a a0 -> a0 # minimum :: Ord a0 => Arg a a0 -> a0 # sum :: Num a0 => Arg a a0 -> a0 # product :: Num a0 => Arg a a0 -> a0 #
Foldable (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> m # foldMap' :: Monoid m => (a -> m) -> Proxy a -> m # foldr :: (a -> b -> b) -> b -> Proxy a -> b # foldr' :: (a -> b -> b) -> b -> Proxy a -> b # foldl :: (b -> a -> b) -> b -> Proxy a -> b # foldl' :: (b -> a -> b) -> b -> Proxy a -> b # foldr1 :: (a -> a -> a) -> Proxy a -> a # foldl1 :: (a -> a -> a) -> Proxy a -> a # toList :: Proxy a -> [a] # null :: Proxy a -> Bool # length :: Proxy a -> Int # elem :: Eq a => a -> Proxy a -> Bool # maximum :: Ord a => Proxy a -> a # minimum :: Ord a => Proxy a -> a # sum :: Num a => Proxy a -> a # product :: Num a => Proxy a -> a #
Foldable (Map k)	Folds in order of increasing key.
Instance details Defined in Data.Map.Internal Methods fold :: Monoid m => Map k m -> m # foldMap :: Monoid m => (a -> m) -> Map k a -> m # foldMap' :: Monoid m => (a -> m) -> Map k a -> m # foldr :: (a -> b -> b) -> b -> Map k a -> b # foldr' :: (a -> b -> b) -> b -> Map k a -> b # foldl :: (b -> a -> b) -> b -> Map k a -> b # foldl' :: (b -> a -> b) -> b -> Map k a -> b # foldr1 :: (a -> a -> a) -> Map k a -> a # foldl1 :: (a -> a -> a) -> Map k a -> a # toList :: Map k a -> [a] # null :: Map k a -> Bool # length :: Map k a -> Int # elem :: Eq a => a -> Map k a -> Bool # maximum :: Ord a => Map k a -> a # minimum :: Ord a => Map k a -> a # sum :: Num a => Map k a -> a # product :: Num a => Map k a -> a #
Foldable f => Foldable (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Rec1 f m -> m # foldMap :: Monoid m => (a -> m) -> Rec1 f a -> m # foldMap' :: Monoid m => (a -> m) -> Rec1 f a -> m # foldr :: (a -> b -> b) -> b -> Rec1 f a -> b # foldr' :: (a -> b -> b) -> b -> Rec1 f a -> b # foldl :: (b -> a -> b) -> b -> Rec1 f a -> b # foldl' :: (b -> a -> b) -> b -> Rec1 f a -> b # foldr1 :: (a -> a -> a) -> Rec1 f a -> a # foldl1 :: (a -> a -> a) -> Rec1 f a -> a # toList :: Rec1 f a -> [a] # null :: Rec1 f a -> Bool # length :: Rec1 f a -> Int # elem :: Eq a => a -> Rec1 f a -> Bool # maximum :: Ord a => Rec1 f a -> a # minimum :: Ord a => Rec1 f a -> a # sum :: Num a => Rec1 f a -> a # product :: Num a => Rec1 f a -> a #
Foldable (Const m :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Functor.Const Methods fold :: Monoid m0 => Const m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldr :: (a -> b -> b) -> b -> Const m a -> b # foldr' :: (a -> b -> b) -> b -> Const m a -> b # foldl :: (b -> a -> b) -> b -> Const m a -> b # foldl' :: (b -> a -> b) -> b -> Const m a -> b # foldr1 :: (a -> a -> a) -> Const m a -> a # foldl1 :: (a -> a -> a) -> Const m a -> a # toList :: Const m a -> [a] # null :: Const m a -> Bool # length :: Const m a -> Int # elem :: Eq a => a -> Const m a -> Bool # maximum :: Ord a => Const m a -> a # minimum :: Ord a => Const m a -> a # sum :: Num a => Const m a -> a # product :: Num a => Const m a -> a #
Foldable f => Foldable (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Ap f m -> m # foldMap :: Monoid m => (a -> m) -> Ap f a -> m # foldMap' :: Monoid m => (a -> m) -> Ap f a -> m # foldr :: (a -> b -> b) -> b -> Ap f a -> b # foldr' :: (a -> b -> b) -> b -> Ap f a -> b # foldl :: (b -> a -> b) -> b -> Ap f a -> b # foldl' :: (b -> a -> b) -> b -> Ap f a -> b # foldr1 :: (a -> a -> a) -> Ap f a -> a # foldl1 :: (a -> a -> a) -> Ap f a -> a # toList :: Ap f a -> [a] # null :: Ap f a -> Bool # length :: Ap f a -> Int # elem :: Eq a => a -> Ap f a -> Bool # maximum :: Ord a => Ap f a -> a # minimum :: Ord a => Ap f a -> a # sum :: Num a => Ap f a -> a # product :: Num a => Ap f a -> a #
Foldable f => Foldable (Alt f)	Since: base-4.12.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Alt f m -> m # foldMap :: Monoid m => (a -> m) -> Alt f a -> m # foldMap' :: Monoid m => (a -> m) -> Alt f a -> m # foldr :: (a -> b -> b) -> b -> Alt f a -> b # foldr' :: (a -> b -> b) -> b -> Alt f a -> b # foldl :: (b -> a -> b) -> b -> Alt f a -> b # foldl' :: (b -> a -> b) -> b -> Alt f a -> b # foldr1 :: (a -> a -> a) -> Alt f a -> a # foldl1 :: (a -> a -> a) -> Alt f a -> a # toList :: Alt f a -> [a] # null :: Alt f a -> Bool # length :: Alt f a -> Int # elem :: Eq a => a -> Alt f a -> Bool # maximum :: Ord a => Alt f a -> a # minimum :: Ord a => Alt f a -> a # sum :: Num a => Alt f a -> a # product :: Num a => Alt f a -> a #
Foldable f => Foldable (ErrorT e f)
Instance details Defined in Control.Monad.Trans.Error Methods fold :: Monoid m => ErrorT e f m -> m # foldMap :: Monoid m => (a -> m) -> ErrorT e f a -> m # foldMap' :: Monoid m => (a -> m) -> ErrorT e f a -> m # foldr :: (a -> b -> b) -> b -> ErrorT e f a -> b # foldr' :: (a -> b -> b) -> b -> ErrorT e f a -> b # foldl :: (b -> a -> b) -> b -> ErrorT e f a -> b # foldl' :: (b -> a -> b) -> b -> ErrorT e f a -> b # foldr1 :: (a -> a -> a) -> ErrorT e f a -> a # foldl1 :: (a -> a -> a) -> ErrorT e f a -> a # toList :: ErrorT e f a -> [a] # null :: ErrorT e f a -> Bool # length :: ErrorT e f a -> Int # elem :: Eq a => a -> ErrorT e f a -> Bool # maximum :: Ord a => ErrorT e f a -> a # minimum :: Ord a => ErrorT e f a -> a # sum :: Num a => ErrorT e f a -> a # product :: Num a => ErrorT e f a -> a #
Foldable (K1 i c :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => K1 i c m -> m # foldMap :: Monoid m => (a -> m) -> K1 i c a -> m # foldMap' :: Monoid m => (a -> m) -> K1 i c a -> m # foldr :: (a -> b -> b) -> b -> K1 i c a -> b # foldr' :: (a -> b -> b) -> b -> K1 i c a -> b # foldl :: (b -> a -> b) -> b -> K1 i c a -> b # foldl' :: (b -> a -> b) -> b -> K1 i c a -> b # foldr1 :: (a -> a -> a) -> K1 i c a -> a # foldl1 :: (a -> a -> a) -> K1 i c a -> a # toList :: K1 i c a -> [a] # null :: K1 i c a -> Bool # length :: K1 i c a -> Int # elem :: Eq a => a -> K1 i c a -> Bool # maximum :: Ord a => K1 i c a -> a # minimum :: Ord a => K1 i c a -> a # sum :: Num a => K1 i c a -> a # product :: Num a => K1 i c a -> a #
(Foldable f, Foldable g) => Foldable (f :+: g)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => (f :+: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :+: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :+: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :+: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :+: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :+: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :+: g) a -> b # foldr1 :: (a -> a -> a) -> (f :+: g) a -> a # foldl1 :: (a -> a -> a) -> (f :+: g) a -> a # toList :: (f :+: g) a -> [a] # null :: (f :+: g) a -> Bool # length :: (f :+: g) a -> Int # elem :: Eq a => a -> (f :+: g) a -> Bool # maximum :: Ord a => (f :+: g) a -> a # minimum :: Ord a => (f :+: g) a -> a # sum :: Num a => (f :+: g) a -> a # product :: Num a => (f :+: g) a -> a #
(Foldable f, Foldable g) => Foldable (f :*: g)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => (f :: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :: g) a -> b # foldr1 :: (a -> a -> a) -> (f :: g) a -> a # foldl1 :: (a -> a -> a) -> (f :: g) a -> a # toList :: (f :: g) a -> [a] # null :: (f :: g) a -> Bool # length :: (f :: g) a -> Int # elem :: Eq a => a -> (f :: g) a -> Bool # maximum :: Ord a => (f :: g) a -> a # minimum :: Ord a => (f :: g) a -> a # sum :: Num a => (f :: g) a -> a # product :: Num a => (f :*: g) a -> a #
(Foldable f, Foldable g) => Foldable (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods fold :: Monoid m => Product f g m -> m # foldMap :: Monoid m => (a -> m) -> Product f g a -> m # foldMap' :: Monoid m => (a -> m) -> Product f g a -> m # foldr :: (a -> b -> b) -> b -> Product f g a -> b # foldr' :: (a -> b -> b) -> b -> Product f g a -> b # foldl :: (b -> a -> b) -> b -> Product f g a -> b # foldl' :: (b -> a -> b) -> b -> Product f g a -> b # foldr1 :: (a -> a -> a) -> Product f g a -> a # foldl1 :: (a -> a -> a) -> Product f g a -> a # toList :: Product f g a -> [a] # null :: Product f g a -> Bool # length :: Product f g a -> Int # elem :: Eq a => a -> Product f g a -> Bool # maximum :: Ord a => Product f g a -> a # minimum :: Ord a => Product f g a -> a # sum :: Num a => Product f g a -> a # product :: Num a => Product f g a -> a #
(Foldable f, Foldable g) => Foldable (Sum f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods fold :: Monoid m => Sum f g m -> m # foldMap :: Monoid m => (a -> m) -> Sum f g a -> m # foldMap' :: Monoid m => (a -> m) -> Sum f g a -> m # foldr :: (a -> b -> b) -> b -> Sum f g a -> b # foldr' :: (a -> b -> b) -> b -> Sum f g a -> b # foldl :: (b -> a -> b) -> b -> Sum f g a -> b # foldl' :: (b -> a -> b) -> b -> Sum f g a -> b # foldr1 :: (a -> a -> a) -> Sum f g a -> a # foldl1 :: (a -> a -> a) -> Sum f g a -> a # toList :: Sum f g a -> [a] # null :: Sum f g a -> Bool # length :: Sum f g a -> Int # elem :: Eq a => a -> Sum f g a -> Bool # maximum :: Ord a => Sum f g a -> a # minimum :: Ord a => Sum f g a -> a # sum :: Num a => Sum f g a -> a # product :: Num a => Sum f g a -> a #
Foldable f => Foldable (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => M1 i c f m -> m # foldMap :: Monoid m => (a -> m) -> M1 i c f a -> m # foldMap' :: Monoid m => (a -> m) -> M1 i c f a -> m # foldr :: (a -> b -> b) -> b -> M1 i c f a -> b # foldr' :: (a -> b -> b) -> b -> M1 i c f a -> b # foldl :: (b -> a -> b) -> b -> M1 i c f a -> b # foldl' :: (b -> a -> b) -> b -> M1 i c f a -> b # foldr1 :: (a -> a -> a) -> M1 i c f a -> a # foldl1 :: (a -> a -> a) -> M1 i c f a -> a # toList :: M1 i c f a -> [a] # null :: M1 i c f a -> Bool # length :: M1 i c f a -> Int # elem :: Eq a => a -> M1 i c f a -> Bool # maximum :: Ord a => M1 i c f a -> a # minimum :: Ord a => M1 i c f a -> a # sum :: Num a => M1 i c f a -> a # product :: Num a => M1 i c f a -> a #
(Foldable f, Foldable g) => Foldable (f :.: g)	Since: base-4.9.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => (f :.: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :.: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :.: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :.: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :.: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :.: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :.: g) a -> b # foldr1 :: (a -> a -> a) -> (f :.: g) a -> a # foldl1 :: (a -> a -> a) -> (f :.: g) a -> a # toList :: (f :.: g) a -> [a] # null :: (f :.: g) a -> Bool # length :: (f :.: g) a -> Int # elem :: Eq a => a -> (f :.: g) a -> Bool # maximum :: Ord a => (f :.: g) a -> a # minimum :: Ord a => (f :.: g) a -> a # sum :: Num a => (f :.: g) a -> a # product :: Num a => (f :.: g) a -> a #
(Foldable f, Foldable g) => Foldable (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods fold :: Monoid m => Compose f g m -> m # foldMap :: Monoid m => (a -> m) -> Compose f g a -> m # foldMap' :: Monoid m => (a -> m) -> Compose f g a -> m # foldr :: (a -> b -> b) -> b -> Compose f g a -> b # foldr' :: (a -> b -> b) -> b -> Compose f g a -> b # foldl :: (b -> a -> b) -> b -> Compose f g a -> b # foldl' :: (b -> a -> b) -> b -> Compose f g a -> b # foldr1 :: (a -> a -> a) -> Compose f g a -> a # foldl1 :: (a -> a -> a) -> Compose f g a -> a # toList :: Compose f g a -> [a] # null :: Compose f g a -> Bool # length :: Compose f g a -> Int # elem :: Eq a => a -> Compose f g a -> Bool # maximum :: Ord a => Compose f g a -> a # minimum :: Ord a => Compose f g a -> a # sum :: Num a => Compose f g a -> a # product :: Num a => Compose f g a -> a #

all :: Foldable t => (a -> Bool) -> t a -> Bool #

Determines whether all elements of the structure satisfy the predicate.

and :: Foldable t => t Bool -> Bool #

and returns the conjunction of a container of Bools. For the result to be True, the container must be finite; False, however, results from a False value finitely far from the left end.

any :: Foldable t => (a -> Bool) -> t a -> Bool #

Determines whether any element of the structure satisfies the predicate.

asum :: (Foldable t, Alternative f) => t (f a) -> f a #

The sum of a collection of actions, generalizing concat.

>>> asum [Just "Hello", Nothing, Just "World"]
Just "Hello"

concat :: Foldable t => t [a] -> [a] #

The concatenation of all the elements of a container of lists.

concatMap :: Foldable t => (a -> [b]) -> t a -> [b] #

Map a function over all the elements of a container and concatenate the resulting lists.

find :: Foldable t => (a -> Bool) -> t a -> Maybe a #

The find function takes a predicate and a structure and returns the leftmost element of the structure matching the predicate, or Nothing if there is no such element.

foldlM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b #

Monadic fold over the elements of a structure, associating to the left, i.e. from left to right.

foldrM :: (Foldable t, Monad m) => (a -> b -> m b) -> b -> t a -> m b #

Monadic fold over the elements of a structure, associating to the right, i.e. from right to left.

for_ :: (Foldable t, Applicative f) => t a -> (a -> f b) -> f () #

for_ is traverse_ with its arguments flipped. For a version that doesn't ignore the results see for.

>>> for_ [1..4] print
1
2
3
4

length :: Foldable t => t a -> Int #

Returns the size/length of a finite structure as an Int. The default implementation is optimized for structures that are similar to cons-lists, because there is no general way to do better.

Since: base-4.8.0.0

notElem :: (Foldable t, Eq a) => a -> t a -> Bool infix 4 #

notElem is the negation of elem.

null :: Foldable t => t a -> Bool #

Test whether the structure is empty. The default implementation is optimized for structures that are similar to cons-lists, because there is no general way to do better.

Since: base-4.8.0.0

or :: Foldable t => t Bool -> Bool #

or returns the disjunction of a container of Bools. For the result to be False, the container must be finite; True, however, results from a True value finitely far from the left end.

sequenceA_ :: (Foldable t, Applicative f) => t (f a) -> f () #

Evaluate each action in the structure from left to right, and ignore the results. For a version that doesn't ignore the results see sequenceA.

traverse_ :: (Foldable t, Applicative f) => (a -> f b) -> t a -> f () #

Map each element of a structure to an action, evaluate these actions from left to right, and ignore the results. For a version that doesn't ignore the results see traverse.

foldl1May :: Foldable t => (a -> a -> a) -> t a -> Maybe a #

foldr1May :: Foldable t => (a -> a -> a) -> t a -> Maybe a #

maximumBound :: (Foldable f, Ord a) => a -> f a -> a #

maximumBoundBy :: Foldable f => a -> (a -> a -> Ordering) -> f a -> a #

maximumBounded :: (Foldable f, Ord a, Bounded a) => f a -> a #

maximumByMay :: Foldable t => (a -> a -> Ordering) -> t a -> Maybe a #

maximumMay :: (Foldable t, Ord a) => t a -> Maybe a #

minimumBound :: (Foldable f, Ord a) => a -> f a -> a #

minimumBoundBy :: Foldable f => a -> (a -> a -> Ordering) -> f a -> a #

minimumBounded :: (Foldable f, Ord a, Bounded a) => f a -> a #

minimumByMay :: Foldable t => (a -> a -> Ordering) -> t a -> Maybe a #

minimumMay :: (Foldable t, Ord a) => t a -> Maybe a #

Traversable

class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where #

Functors representing data structures that can be traversed from left to right.

A definition of traverse must satisfy the following laws:

Naturality: t . traverse f = traverse (t . f) for every applicative transformation t
Identity: traverse Identity = Identity
Composition: traverse (Compose . fmap g . f) = Compose . fmap (traverse g) . traverse f

A definition of sequenceA must satisfy the following laws:

Naturality: t . sequenceA = sequenceA . fmap t for every applicative transformation t
Identity: sequenceA . fmap Identity = Identity
Composition: sequenceA . fmap Compose = Compose . fmap sequenceA . sequenceA

where an applicative transformation is a function

t :: (Applicative f, Applicative g) => f a -> g a

preserving the Applicative operations, i.e.

t (pure x) = pure x
t (f <*> x) = t f <*> t x

and the identity functor Identity and composition functors Compose are from Data.Functor.Identity and Data.Functor.Compose.

A result of the naturality law is a purity law for traverse

traverse pure = pure

(The naturality law is implied by parametricity and thus so is the purity law [1, p15].)

Instances are similar to Functor, e.g. given a data type

data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)

a suitable instance would be

instance Traversable Tree where
   traverse f Empty = pure Empty
   traverse f (Leaf x) = Leaf <$> f x
   traverse f (Node l k r) = Node <$> traverse f l <*> f k <*> traverse f r

This is suitable even for abstract types, as the laws for <*> imply a form of associativity.

The superclass instances should satisfy the following:

In the Functor instance, fmap should be equivalent to traversal with the identity applicative functor (fmapDefault).
In the Foldable instance, foldMap should be equivalent to traversal with a constant applicative functor (foldMapDefault).

References: [1] The Essence of the Iterator Pattern, Jeremy Gibbons and Bruno C. d. S. Oliveira

Minimal complete definition

traverse | sequenceA

Methods

traverse :: Applicative f => (a -> f b) -> t a -> f (t b) #

Map each element of a structure to an action, evaluate these actions from left to right, and collect the results. For a version that ignores the results see traverse_.

sequenceA :: Applicative f => t (f a) -> f (t a) #

Evaluate each action in the structure from left to right, and collect the results. For a version that ignores the results see sequenceA_.

Instances

Instances details

Traversable []	Since: base-2.1
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> [a] -> f [b] # sequenceA :: Applicative f => [f a] -> f [a] # mapM :: Monad m => (a -> m b) -> [a] -> m [b] # sequence :: Monad m => [m a] -> m [a] #
Traversable Maybe	Since: base-2.1
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Maybe a -> f (Maybe b) # sequenceA :: Applicative f => Maybe (f a) -> f (Maybe a) # mapM :: Monad m => (a -> m b) -> Maybe a -> m (Maybe b) # sequence :: Monad m => Maybe (m a) -> m (Maybe a) #
Traversable Par1	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Par1 a -> f (Par1 b) # sequenceA :: Applicative f => Par1 (f a) -> f (Par1 a) # mapM :: Monad m => (a -> m b) -> Par1 a -> m (Par1 b) # sequence :: Monad m => Par1 (m a) -> m (Par1 a) #
Traversable Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a -> f b) -> Min a -> f (Min b) # sequenceA :: Applicative f => Min (f a) -> f (Min a) # mapM :: Monad m => (a -> m b) -> Min a -> m (Min b) # sequence :: Monad m => Min (m a) -> m (Min a) #
Traversable Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a -> f b) -> Max a -> f (Max b) # sequenceA :: Applicative f => Max (f a) -> f (Max a) # mapM :: Monad m => (a -> m b) -> Max a -> m (Max b) # sequence :: Monad m => Max (m a) -> m (Max a) #
Traversable First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a -> f b) -> First a -> f (First b) # sequenceA :: Applicative f => First (f a) -> f (First a) # mapM :: Monad m => (a -> m b) -> First a -> m (First b) # sequence :: Monad m => First (m a) -> m (First a) #
Traversable Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a -> f b) -> Last a -> f (Last b) # sequenceA :: Applicative f => Last (f a) -> f (Last a) # mapM :: Monad m => (a -> m b) -> Last a -> m (Last b) # sequence :: Monad m => Last (m a) -> m (Last a) #
Traversable Option	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a -> f b) -> Option a -> f (Option b) # sequenceA :: Applicative f => Option (f a) -> f (Option a) # mapM :: Monad m => (a -> m b) -> Option a -> m (Option b) # sequence :: Monad m => Option (m a) -> m (Option a) #
Traversable ZipList	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> ZipList a -> f (ZipList b) # sequenceA :: Applicative f => ZipList (f a) -> f (ZipList a) # mapM :: Monad m => (a -> m b) -> ZipList a -> m (ZipList b) # sequence :: Monad m => ZipList (m a) -> m (ZipList a) #
Traversable Identity	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Identity a -> f (Identity b) # sequenceA :: Applicative f => Identity (f a) -> f (Identity a) # mapM :: Monad m => (a -> m b) -> Identity a -> m (Identity b) # sequence :: Monad m => Identity (m a) -> m (Identity a) #
Traversable First	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> First a -> f (First b) # sequenceA :: Applicative f => First (f a) -> f (First a) # mapM :: Monad m => (a -> m b) -> First a -> m (First b) # sequence :: Monad m => First (m a) -> m (First a) #
Traversable Last	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Last a -> f (Last b) # sequenceA :: Applicative f => Last (f a) -> f (Last a) # mapM :: Monad m => (a -> m b) -> Last a -> m (Last b) # sequence :: Monad m => Last (m a) -> m (Last a) #
Traversable Dual	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Dual a -> f (Dual b) # sequenceA :: Applicative f => Dual (f a) -> f (Dual a) # mapM :: Monad m => (a -> m b) -> Dual a -> m (Dual b) # sequence :: Monad m => Dual (m a) -> m (Dual a) #
Traversable Sum	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Sum a -> f (Sum b) # sequenceA :: Applicative f => Sum (f a) -> f (Sum a) # mapM :: Monad m => (a -> m b) -> Sum a -> m (Sum b) # sequence :: Monad m => Sum (m a) -> m (Sum a) #
Traversable Product	Since: base-4.8.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Product a -> f (Product b) # sequenceA :: Applicative f => Product (f a) -> f (Product a) # mapM :: Monad m => (a -> m b) -> Product a -> m (Product b) # sequence :: Monad m => Product (m a) -> m (Product a) #
Traversable Down	Since: base-4.12.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Down a -> f (Down b) # sequenceA :: Applicative f => Down (f a) -> f (Down a) # mapM :: Monad m => (a -> m b) -> Down a -> m (Down b) # sequence :: Monad m => Down (m a) -> m (Down a) #
Traversable NonEmpty	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> NonEmpty a -> f (NonEmpty b) # sequenceA :: Applicative f => NonEmpty (f a) -> f (NonEmpty a) # mapM :: Monad m => (a -> m b) -> NonEmpty a -> m (NonEmpty b) # sequence :: Monad m => NonEmpty (m a) -> m (NonEmpty a) #
Traversable (Either a)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a0 -> f b) -> Either a a0 -> f (Either a b) # sequenceA :: Applicative f => Either a (f a0) -> f (Either a a0) # mapM :: Monad m => (a0 -> m b) -> Either a a0 -> m (Either a b) # sequence :: Monad m => Either a (m a0) -> m (Either a a0) #
Traversable (V1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> V1 a -> f (V1 b) # sequenceA :: Applicative f => V1 (f a) -> f (V1 a) # mapM :: Monad m => (a -> m b) -> V1 a -> m (V1 b) # sequence :: Monad m => V1 (m a) -> m (V1 a) #
Traversable (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> U1 a -> f (U1 b) # sequenceA :: Applicative f => U1 (f a) -> f (U1 a) # mapM :: Monad m => (a -> m b) -> U1 a -> m (U1 b) # sequence :: Monad m => U1 (m a) -> m (U1 a) #
Traversable (UAddr :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UAddr a -> f (UAddr b) # sequenceA :: Applicative f => UAddr (f a) -> f (UAddr a) # mapM :: Monad m => (a -> m b) -> UAddr a -> m (UAddr b) # sequence :: Monad m => UAddr (m a) -> m (UAddr a) #
Traversable (UChar :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UChar a -> f (UChar b) # sequenceA :: Applicative f => UChar (f a) -> f (UChar a) # mapM :: Monad m => (a -> m b) -> UChar a -> m (UChar b) # sequence :: Monad m => UChar (m a) -> m (UChar a) #
Traversable (UDouble :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UDouble a -> f (UDouble b) # sequenceA :: Applicative f => UDouble (f a) -> f (UDouble a) # mapM :: Monad m => (a -> m b) -> UDouble a -> m (UDouble b) # sequence :: Monad m => UDouble (m a) -> m (UDouble a) #
Traversable (UFloat :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UFloat a -> f (UFloat b) # sequenceA :: Applicative f => UFloat (f a) -> f (UFloat a) # mapM :: Monad m => (a -> m b) -> UFloat a -> m (UFloat b) # sequence :: Monad m => UFloat (m a) -> m (UFloat a) #
Traversable (UInt :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UInt a -> f (UInt b) # sequenceA :: Applicative f => UInt (f a) -> f (UInt a) # mapM :: Monad m => (a -> m b) -> UInt a -> m (UInt b) # sequence :: Monad m => UInt (m a) -> m (UInt a) #
Traversable (UWord :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> UWord a -> f (UWord b) # sequenceA :: Applicative f => UWord (f a) -> f (UWord a) # mapM :: Monad m => (a -> m b) -> UWord a -> m (UWord b) # sequence :: Monad m => UWord (m a) -> m (UWord a) #
Traversable ((,) a)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a0 -> f b) -> (a, a0) -> f (a, b) # sequenceA :: Applicative f => (a, f a0) -> f (a, a0) # mapM :: Monad m => (a0 -> m b) -> (a, a0) -> m (a, b) # sequence :: Monad m => (a, m a0) -> m (a, a0) #
Ix i => Traversable (Array i)	Since: base-2.1
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Array i a -> f (Array i b) # sequenceA :: Applicative f => Array i (f a) -> f (Array i a) # mapM :: Monad m => (a -> m b) -> Array i a -> m (Array i b) # sequence :: Monad m => Array i (m a) -> m (Array i a) #
Traversable (Arg a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods traverse :: Applicative f => (a0 -> f b) -> Arg a a0 -> f (Arg a b) # sequenceA :: Applicative f => Arg a (f a0) -> f (Arg a a0) # mapM :: Monad m => (a0 -> m b) -> Arg a a0 -> m (Arg a b) # sequence :: Monad m => Arg a (m a0) -> m (Arg a a0) #
Traversable (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Proxy a -> f (Proxy b) # sequenceA :: Applicative f => Proxy (f a) -> f (Proxy a) # mapM :: Monad m => (a -> m b) -> Proxy a -> m (Proxy b) # sequence :: Monad m => Proxy (m a) -> m (Proxy a) #
Traversable (Map k)	Traverses in order of increasing key.
Instance details Defined in Data.Map.Internal Methods traverse :: Applicative f => (a -> f b) -> Map k a -> f (Map k b) # sequenceA :: Applicative f => Map k (f a) -> f (Map k a) # mapM :: Monad m => (a -> m b) -> Map k a -> m (Map k b) # sequence :: Monad m => Map k (m a) -> m (Map k a) #
Traversable f => Traversable (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> Rec1 f a -> f0 (Rec1 f b) # sequenceA :: Applicative f0 => Rec1 f (f0 a) -> f0 (Rec1 f a) # mapM :: Monad m => (a -> m b) -> Rec1 f a -> m (Rec1 f b) # sequence :: Monad m => Rec1 f (m a) -> m (Rec1 f a) #
Traversable (Const m :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Const m a -> f (Const m b) # sequenceA :: Applicative f => Const m (f a) -> f (Const m a) # mapM :: Monad m0 => (a -> m0 b) -> Const m a -> m0 (Const m b) # sequence :: Monad m0 => Const m (m0 a) -> m0 (Const m a) #
Traversable f => Traversable (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> Ap f a -> f0 (Ap f b) # sequenceA :: Applicative f0 => Ap f (f0 a) -> f0 (Ap f a) # mapM :: Monad m => (a -> m b) -> Ap f a -> m (Ap f b) # sequence :: Monad m => Ap f (m a) -> m (Ap f a) #
Traversable f => Traversable (Alt f)	Since: base-4.12.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> Alt f a -> f0 (Alt f b) # sequenceA :: Applicative f0 => Alt f (f0 a) -> f0 (Alt f a) # mapM :: Monad m => (a -> m b) -> Alt f a -> m (Alt f b) # sequence :: Monad m => Alt f (m a) -> m (Alt f a) #
Traversable f => Traversable (ErrorT e f)
Instance details Defined in Control.Monad.Trans.Error Methods traverse :: Applicative f0 => (a -> f0 b) -> ErrorT e f a -> f0 (ErrorT e f b) # sequenceA :: Applicative f0 => ErrorT e f (f0 a) -> f0 (ErrorT e f a) # mapM :: Monad m => (a -> m b) -> ErrorT e f a -> m (ErrorT e f b) # sequence :: Monad m => ErrorT e f (m a) -> m (ErrorT e f a) #
Traversable (K1 i c :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> K1 i c a -> f (K1 i c b) # sequenceA :: Applicative f => K1 i c (f a) -> f (K1 i c a) # mapM :: Monad m => (a -> m b) -> K1 i c a -> m (K1 i c b) # sequence :: Monad m => K1 i c (m a) -> m (K1 i c a) #
(Traversable f, Traversable g) => Traversable (f :+: g)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> (f :+: g) a -> f0 ((f :+: g) b) # sequenceA :: Applicative f0 => (f :+: g) (f0 a) -> f0 ((f :+: g) a) # mapM :: Monad m => (a -> m b) -> (f :+: g) a -> m ((f :+: g) b) # sequence :: Monad m => (f :+: g) (m a) -> m ((f :+: g) a) #
(Traversable f, Traversable g) => Traversable (f :*: g)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> (f :: g) a -> f0 ((f :: g) b) # sequenceA :: Applicative f0 => (f :: g) (f0 a) -> f0 ((f :: g) a) # mapM :: Monad m => (a -> m b) -> (f :: g) a -> m ((f :: g) b) # sequence :: Monad m => (f :: g) (m a) -> m ((f :: g) a) #
(Traversable f, Traversable g) => Traversable (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods traverse :: Applicative f0 => (a -> f0 b) -> Product f g a -> f0 (Product f g b) # sequenceA :: Applicative f0 => Product f g (f0 a) -> f0 (Product f g a) # mapM :: Monad m => (a -> m b) -> Product f g a -> m (Product f g b) # sequence :: Monad m => Product f g (m a) -> m (Product f g a) #
(Traversable f, Traversable g) => Traversable (Sum f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods traverse :: Applicative f0 => (a -> f0 b) -> Sum f g a -> f0 (Sum f g b) # sequenceA :: Applicative f0 => Sum f g (f0 a) -> f0 (Sum f g a) # mapM :: Monad m => (a -> m b) -> Sum f g a -> m (Sum f g b) # sequence :: Monad m => Sum f g (m a) -> m (Sum f g a) #
Traversable f => Traversable (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> M1 i c f a -> f0 (M1 i c f b) # sequenceA :: Applicative f0 => M1 i c f (f0 a) -> f0 (M1 i c f a) # mapM :: Monad m => (a -> m b) -> M1 i c f a -> m (M1 i c f b) # sequence :: Monad m => M1 i c f (m a) -> m (M1 i c f a) #
(Traversable f, Traversable g) => Traversable (f :.: g)	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f0 => (a -> f0 b) -> (f :.: g) a -> f0 ((f :.: g) b) # sequenceA :: Applicative f0 => (f :.: g) (f0 a) -> f0 ((f :.: g) a) # mapM :: Monad m => (a -> m b) -> (f :.: g) a -> m ((f :.: g) b) # sequence :: Monad m => (f :.: g) (m a) -> m ((f :.: g) a) #
(Traversable f, Traversable g) => Traversable (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods traverse :: Applicative f0 => (a -> f0 b) -> Compose f g a -> f0 (Compose f g b) # sequenceA :: Applicative f0 => Compose f g (f0 a) -> f0 (Compose f g a) # mapM :: Monad m => (a -> m b) -> Compose f g a -> m (Compose f g b) # sequence :: Monad m => Compose f g (m a) -> m (Compose f g a) #

for :: (Traversable t, Applicative f) => t a -> (a -> f b) -> f (t b) #

for is traverse with its arguments flipped. For a version that ignores the results see for_.

mapAccumL :: Traversable t => (a -> b -> (a, c)) -> a -> t b -> (a, t c) #

The mapAccumL function behaves like a combination of fmap and foldl; it applies a function to each element of a structure, passing an accumulating parameter from left to right, and returning a final value of this accumulator together with the new structure.

mapAccumR :: Traversable t => (a -> b -> (a, c)) -> a -> t b -> (a, t c) #

The mapAccumR function behaves like a combination of fmap and foldr; it applies a function to each element of a structure, passing an accumulating parameter from right to left, and returning a final value of this accumulator together with the new structure.

Applicative

class Functor f => Applicative (f :: Type -> Type) where #

A functor with application, providing operations to

embed pure expressions (pure), and
sequence computations and combine their results (<*> and liftA2).

A minimal complete definition must include implementations of pure and of either <*> or liftA2. If it defines both, then they must behave the same as their default definitions:

(<*>) = liftA2 id

liftA2 f x y = f <$> x <*> y

Further, any definition must satisfy the following:

Identity

pure id <*> v = v

Composition

pure (.) <*> u <*> v <*> w = u <*> (v <*> w)

Homomorphism

pure f <*> pure x = pure (f x)

Interchange

u <*> pure y = pure ($ y) <*> u

The other methods have the following default definitions, which may be overridden with equivalent specialized implementations:

```
u *> v = (id <$ u) <*> v
```
```
u <* v = liftA2 const u v
```

As a consequence of these laws, the Functor instance for f will satisfy

```
fmap f x = pure f <*> x
```

It may be useful to note that supposing

forall x y. p (q x y) = f x . g y

it follows from the above that

liftA2 p (liftA2 q u v) = liftA2 f u . liftA2 g v

If f is also a Monad, it should satisfy

```
pure = return
```

m1 <*> m2 = m1 >>= (x1 -> m2 >>= (x2 -> return (x1 x2)))

```
(*>) = (>>)
```

(which implies that pure and <*> satisfy the applicative functor laws).

Minimal complete definition

pure, ((<*>) | liftA2)

Methods

pure :: a -> f a #

Lift a value.

(<*>) :: f (a -> b) -> f a -> f b infixl 4 #

Sequential application.

A few functors support an implementation of <*> that is more efficient than the default one.

Using ApplicativeDo: 'fs <*> as' can be understood as the do expression

do f <- fs
   a <- as
   pure (f a)

(*>) :: f a -> f b -> f b infixl 4 #

Sequence actions, discarding the value of the first argument.

'as *> bs' can be understood as the do expression

do as
   bs

This is a tad complicated for our ApplicativeDo extension which will give it a Monad constraint. For an Applicative constraint we write it of the form

do _ <- as
   b <- bs
   pure b

(<*) :: f a -> f b -> f a infixl 4 #

Sequence actions, discarding the value of the second argument.

Using ApplicativeDo: 'as <* bs' can be understood as the do expression

do a <- as
   bs
   pure a

Instances

Instances details

Applicative []	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> [a] # (<>) :: [a -> b] -> [a] -> [b] # liftA2 :: (a -> b -> c) -> [a] -> [b] -> [c] # (>) :: [a] -> [b] -> [b] # (<*) :: [a] -> [b] -> [a] #
Applicative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> Maybe a # (<>) :: Maybe (a -> b) -> Maybe a -> Maybe b # liftA2 :: (a -> b -> c) -> Maybe a -> Maybe b -> Maybe c # (>) :: Maybe a -> Maybe b -> Maybe b # (<*) :: Maybe a -> Maybe b -> Maybe a #
Applicative IO	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> IO a # (<>) :: IO (a -> b) -> IO a -> IO b # liftA2 :: (a -> b -> c) -> IO a -> IO b -> IO c # (>) :: IO a -> IO b -> IO b # (<*) :: IO a -> IO b -> IO a #
Applicative Par1	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> Par1 a # (<>) :: Par1 (a -> b) -> Par1 a -> Par1 b # liftA2 :: (a -> b -> c) -> Par1 a -> Par1 b -> Par1 c # (>) :: Par1 a -> Par1 b -> Par1 b # (<*) :: Par1 a -> Par1 b -> Par1 a #
Applicative Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Min a # (<>) :: Min (a -> b) -> Min a -> Min b # liftA2 :: (a -> b -> c) -> Min a -> Min b -> Min c # (>) :: Min a -> Min b -> Min b # (<*) :: Min a -> Min b -> Min a #
Applicative Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Max a # (<>) :: Max (a -> b) -> Max a -> Max b # liftA2 :: (a -> b -> c) -> Max a -> Max b -> Max c # (>) :: Max a -> Max b -> Max b # (<*) :: Max a -> Max b -> Max a #
Applicative First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> First a # (<>) :: First (a -> b) -> First a -> First b # liftA2 :: (a -> b -> c) -> First a -> First b -> First c # (>) :: First a -> First b -> First b # (<*) :: First a -> First b -> First a #
Applicative Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Last a # (<>) :: Last (a -> b) -> Last a -> Last b # liftA2 :: (a -> b -> c) -> Last a -> Last b -> Last c # (>) :: Last a -> Last b -> Last b # (<*) :: Last a -> Last b -> Last a #
Applicative Option	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Option a # (<>) :: Option (a -> b) -> Option a -> Option b # liftA2 :: (a -> b -> c) -> Option a -> Option b -> Option c # (>) :: Option a -> Option b -> Option b # (<*) :: Option a -> Option b -> Option a #
Applicative ZipList	f <$> ZipList xs1 <> ... <> ZipList xsN = ZipList (zipWithN f xs1 ... xsN) where `zipWithN` refers to the `zipWith` function of the appropriate arity (`zipWith`, `zipWith3`, `zipWith4`, ...). For example: (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <> ZipList "567" <> ZipList [1..] = ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..]) = ZipList {getZipList = ["a5","b6b6","c7c7c7"]} Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a -> ZipList a # (<>) :: ZipList (a -> b) -> ZipList a -> ZipList b # liftA2 :: (a -> b -> c) -> ZipList a -> ZipList b -> ZipList c # (>) :: ZipList a -> ZipList b -> ZipList b # (<*) :: ZipList a -> ZipList b -> ZipList a #
Applicative Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods pure :: a -> Identity a # (<>) :: Identity (a -> b) -> Identity a -> Identity b # liftA2 :: (a -> b -> c) -> Identity a -> Identity b -> Identity c # (>) :: Identity a -> Identity b -> Identity b # (<*) :: Identity a -> Identity b -> Identity a #
Applicative STM	Since: base-4.8.0.0
Instance details Defined in GHC.Conc.Sync Methods pure :: a -> STM a # (<>) :: STM (a -> b) -> STM a -> STM b # liftA2 :: (a -> b -> c) -> STM a -> STM b -> STM c # (>) :: STM a -> STM b -> STM b # (<*) :: STM a -> STM b -> STM a #
Applicative First	Since: base-4.8.0.0
Instance details Defined in Data.Monoid Methods pure :: a -> First a # (<>) :: First (a -> b) -> First a -> First b # liftA2 :: (a -> b -> c) -> First a -> First b -> First c # (>) :: First a -> First b -> First b # (<*) :: First a -> First b -> First a #
Applicative Last	Since: base-4.8.0.0
Instance details Defined in Data.Monoid Methods pure :: a -> Last a # (<>) :: Last (a -> b) -> Last a -> Last b # liftA2 :: (a -> b -> c) -> Last a -> Last b -> Last c # (>) :: Last a -> Last b -> Last b # (<*) :: Last a -> Last b -> Last a #
Applicative Dual	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Dual a # (<>) :: Dual (a -> b) -> Dual a -> Dual b # liftA2 :: (a -> b -> c) -> Dual a -> Dual b -> Dual c # (>) :: Dual a -> Dual b -> Dual b # (<*) :: Dual a -> Dual b -> Dual a #
Applicative Sum	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Sum a # (<>) :: Sum (a -> b) -> Sum a -> Sum b # liftA2 :: (a -> b -> c) -> Sum a -> Sum b -> Sum c # (>) :: Sum a -> Sum b -> Sum b # (<*) :: Sum a -> Sum b -> Sum a #
Applicative Product	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Product a # (<>) :: Product (a -> b) -> Product a -> Product b # liftA2 :: (a -> b -> c) -> Product a -> Product b -> Product c # (>) :: Product a -> Product b -> Product b # (<*) :: Product a -> Product b -> Product a #
Applicative Down	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods pure :: a -> Down a # (<>) :: Down (a -> b) -> Down a -> Down b # liftA2 :: (a -> b -> c) -> Down a -> Down b -> Down c # (>) :: Down a -> Down b -> Down b # (<*) :: Down a -> Down b -> Down a #
Applicative ReadP	Since: base-4.6.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods pure :: a -> ReadP a # (<>) :: ReadP (a -> b) -> ReadP a -> ReadP b # liftA2 :: (a -> b -> c) -> ReadP a -> ReadP b -> ReadP c # (>) :: ReadP a -> ReadP b -> ReadP b # (<*) :: ReadP a -> ReadP b -> ReadP a #
Applicative NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods pure :: a -> NonEmpty a # (<>) :: NonEmpty (a -> b) -> NonEmpty a -> NonEmpty b # liftA2 :: (a -> b -> c) -> NonEmpty a -> NonEmpty b -> NonEmpty c # (>) :: NonEmpty a -> NonEmpty b -> NonEmpty b # (<*) :: NonEmpty a -> NonEmpty b -> NonEmpty a #
Applicative P	Since: base-4.5.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods pure :: a -> P a # (<>) :: P (a -> b) -> P a -> P b # liftA2 :: (a -> b -> c) -> P a -> P b -> P c # (>) :: P a -> P b -> P b # (<*) :: P a -> P b -> P a #
Applicative (Either e)	Since: base-3.0
Instance details Defined in Data.Either Methods pure :: a -> Either e a # (<>) :: Either e (a -> b) -> Either e a -> Either e b # liftA2 :: (a -> b -> c) -> Either e a -> Either e b -> Either e c # (>) :: Either e a -> Either e b -> Either e b # (<*) :: Either e a -> Either e b -> Either e a #
Applicative (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> U1 a # (<>) :: U1 (a -> b) -> U1 a -> U1 b # liftA2 :: (a -> b -> c) -> U1 a -> U1 b -> U1 c # (>) :: U1 a -> U1 b -> U1 b # (<*) :: U1 a -> U1 b -> U1 a #
Monoid a => Applicative ((,) a)	For tuples, the `Monoid` constraint on `a` determines how the first values merge. For example, `String`s concatenate: ("hello ", (+15)) <> ("world!", 2002) ("hello world!",2017) Since: base-2.1*
Instance details Defined in GHC.Base Methods pure :: a0 -> (a, a0) # (<>) :: (a, a0 -> b) -> (a, a0) -> (a, b) # liftA2 :: (a0 -> b -> c) -> (a, a0) -> (a, b) -> (a, c) # (>) :: (a, a0) -> (a, b) -> (a, b) # (<*) :: (a, a0) -> (a, b) -> (a, a0) #
Monad m => Applicative (WrappedMonad m)	Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a -> WrappedMonad m a # (<>) :: WrappedMonad m (a -> b) -> WrappedMonad m a -> WrappedMonad m b # liftA2 :: (a -> b -> c) -> WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m c # (>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # (<*) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m a #
Arrow a => Applicative (ArrowMonad a)	Since: base-4.6.0.0
Instance details Defined in Control.Arrow Methods pure :: a0 -> ArrowMonad a a0 # (<>) :: ArrowMonad a (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b # liftA2 :: (a0 -> b -> c) -> ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a c # (>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b # (<*) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a a0 #
Applicative (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods pure :: a -> Proxy a # (<>) :: Proxy (a -> b) -> Proxy a -> Proxy b # liftA2 :: (a -> b -> c) -> Proxy a -> Proxy b -> Proxy c # (>) :: Proxy a -> Proxy b -> Proxy b # (<*) :: Proxy a -> Proxy b -> Proxy a #
Applicative f => Applicative (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> Rec1 f a # (<>) :: Rec1 f (a -> b) -> Rec1 f a -> Rec1 f b # liftA2 :: (a -> b -> c) -> Rec1 f a -> Rec1 f b -> Rec1 f c # (>) :: Rec1 f a -> Rec1 f b -> Rec1 f b # (<*) :: Rec1 f a -> Rec1 f b -> Rec1 f a #
(Monoid a, Monoid b) => Applicative ((,,) a b)	Since: base-4.14.0.0
Instance details Defined in GHC.Base Methods pure :: a0 -> (a, b, a0) # (<>) :: (a, b, a0 -> b0) -> (a, b, a0) -> (a, b, b0) # liftA2 :: (a0 -> b0 -> c) -> (a, b, a0) -> (a, b, b0) -> (a, b, c) # (>) :: (a, b, a0) -> (a, b, b0) -> (a, b, b0) # (<*) :: (a, b, a0) -> (a, b, b0) -> (a, b, a0) #
Arrow a => Applicative (WrappedArrow a b)	Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a0 -> WrappedArrow a b a0 # (<>) :: WrappedArrow a b (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # liftA2 :: (a0 -> b0 -> c) -> WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b c # (>) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b b0 # (<*) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 #
Applicative m => Applicative (Kleisli m a)	Since: base-4.14.0.0
Instance details Defined in Control.Arrow Methods pure :: a0 -> Kleisli m a a0 # (<>) :: Kleisli m a (a0 -> b) -> Kleisli m a a0 -> Kleisli m a b # liftA2 :: (a0 -> b -> c) -> Kleisli m a a0 -> Kleisli m a b -> Kleisli m a c # (>) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a b # (<*) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a a0 #
Monoid m => Applicative (Const m :: Type -> Type)	Since: base-2.0.1
Instance details Defined in Data.Functor.Const Methods pure :: a -> Const m a # (<>) :: Const m (a -> b) -> Const m a -> Const m b # liftA2 :: (a -> b -> c) -> Const m a -> Const m b -> Const m c # (>) :: Const m a -> Const m b -> Const m b # (<*) :: Const m a -> Const m b -> Const m a #
Applicative f => Applicative (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods pure :: a -> Ap f a # (<>) :: Ap f (a -> b) -> Ap f a -> Ap f b # liftA2 :: (a -> b -> c) -> Ap f a -> Ap f b -> Ap f c # (>) :: Ap f a -> Ap f b -> Ap f b # (<*) :: Ap f a -> Ap f b -> Ap f a #
Applicative f => Applicative (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Alt f a # (<>) :: Alt f (a -> b) -> Alt f a -> Alt f b # liftA2 :: (a -> b -> c) -> Alt f a -> Alt f b -> Alt f c # (>) :: Alt f a -> Alt f b -> Alt f b # (<*) :: Alt f a -> Alt f b -> Alt f a #
(Functor m, Monad m) => Applicative (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods pure :: a -> ErrorT e m a # (<>) :: ErrorT e m (a -> b) -> ErrorT e m a -> ErrorT e m b # liftA2 :: (a -> b -> c) -> ErrorT e m a -> ErrorT e m b -> ErrorT e m c # (>) :: ErrorT e m a -> ErrorT e m b -> ErrorT e m b # (<*) :: ErrorT e m a -> ErrorT e m b -> ErrorT e m a #
Applicative ((->) r :: Type -> Type)	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> r -> a # (<>) :: (r -> (a -> b)) -> (r -> a) -> r -> b # liftA2 :: (a -> b -> c) -> (r -> a) -> (r -> b) -> r -> c # (>) :: (r -> a) -> (r -> b) -> r -> b # (<*) :: (r -> a) -> (r -> b) -> r -> a #
Monoid c => Applicative (K1 i c :: Type -> Type)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> K1 i c a # (<>) :: K1 i c (a -> b) -> K1 i c a -> K1 i c b # liftA2 :: (a -> b -> c0) -> K1 i c a -> K1 i c b -> K1 i c c0 # (>) :: K1 i c a -> K1 i c b -> K1 i c b # (<*) :: K1 i c a -> K1 i c b -> K1 i c a #
(Applicative f, Applicative g) => Applicative (f :*: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> (f :: g) a # (<>) :: (f :: g) (a -> b) -> (f :: g) a -> (f :: g) b # liftA2 :: (a -> b -> c) -> (f :: g) a -> (f :: g) b -> (f :: g) c # (>) :: (f :: g) a -> (f :: g) b -> (f :: g) b # (<) :: (f :: g) a -> (f :: g) b -> (f :: g) a #
(Monoid a, Monoid b, Monoid c) => Applicative ((,,,) a b c)	Since: base-4.14.0.0
Instance details Defined in GHC.Base Methods pure :: a0 -> (a, b, c, a0) # (<>) :: (a, b, c, a0 -> b0) -> (a, b, c, a0) -> (a, b, c, b0) # liftA2 :: (a0 -> b0 -> c0) -> (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, c0) # (>) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, b0) # (<*) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, a0) #
(Applicative f, Applicative g) => Applicative (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods pure :: a -> Product f g a # (<>) :: Product f g (a -> b) -> Product f g a -> Product f g b # liftA2 :: (a -> b -> c) -> Product f g a -> Product f g b -> Product f g c # (>) :: Product f g a -> Product f g b -> Product f g b # (<*) :: Product f g a -> Product f g b -> Product f g a #
(Applicative f, Monad f) => Applicative (WhenMissing f k x)	Equivalent to `ReaderT k (ReaderT x (MaybeT f))` . Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods pure :: a -> WhenMissing f k x a # (<>) :: WhenMissing f k x (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b # liftA2 :: (a -> b -> c) -> WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x c # (>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # (<*) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x a #
Applicative f => Applicative (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> M1 i c f a # (<>) :: M1 i c f (a -> b) -> M1 i c f a -> M1 i c f b # liftA2 :: (a -> b -> c0) -> M1 i c f a -> M1 i c f b -> M1 i c f c0 # (>) :: M1 i c f a -> M1 i c f b -> M1 i c f b # (<*) :: M1 i c f a -> M1 i c f b -> M1 i c f a #
(Applicative f, Applicative g) => Applicative (f :.: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> (f :.: g) a # (<>) :: (f :.: g) (a -> b) -> (f :.: g) a -> (f :.: g) b # liftA2 :: (a -> b -> c) -> (f :.: g) a -> (f :.: g) b -> (f :.: g) c # (>) :: (f :.: g) a -> (f :.: g) b -> (f :.: g) b # (<*) :: (f :.: g) a -> (f :.: g) b -> (f :.: g) a #
(Applicative f, Applicative g) => Applicative (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods pure :: a -> Compose f g a # (<>) :: Compose f g (a -> b) -> Compose f g a -> Compose f g b # liftA2 :: (a -> b -> c) -> Compose f g a -> Compose f g b -> Compose f g c # (>) :: Compose f g a -> Compose f g b -> Compose f g b # (<*) :: Compose f g a -> Compose f g b -> Compose f g a #
(Monad f, Applicative f) => Applicative (WhenMatched f k x y)	Equivalent to `ReaderT k (ReaderT x (ReaderT y (MaybeT f)))` Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods pure :: a -> WhenMatched f k x y a # (<>) :: WhenMatched f k x y (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b # liftA2 :: (a -> b -> c) -> WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y c # (>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # (<*) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y a #

newtype ZipList a #

Lists, but with an Applicative functor based on zipping.

Constructors

ZipList
Fields getZipList :: [a]

Instances

Instances details

Functor ZipList	Since: base-2.1
Instance details Defined in Control.Applicative Methods fmap :: (a -> b) -> ZipList a -> ZipList b # (<$) :: a -> ZipList b -> ZipList a #
Applicative ZipList	f <$> ZipList xs1 <> ... <> ZipList xsN = ZipList (zipWithN f xs1 ... xsN) where `zipWithN` refers to the `zipWith` function of the appropriate arity (`zipWith`, `zipWith3`, `zipWith4`, ...). For example: (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <> ZipList "567" <> ZipList [1..] = ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..]) = ZipList {getZipList = ["a5","b6b6","c7c7c7"]} Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a -> ZipList a # (<>) :: ZipList (a -> b) -> ZipList a -> ZipList b # liftA2 :: (a -> b -> c) -> ZipList a -> ZipList b -> ZipList c # (>) :: ZipList a -> ZipList b -> ZipList b # (<*) :: ZipList a -> ZipList b -> ZipList a #
Foldable ZipList	Since: base-4.9.0.0
Instance details Defined in Control.Applicative Methods fold :: Monoid m => ZipList m -> m # foldMap :: Monoid m => (a -> m) -> ZipList a -> m # foldMap' :: Monoid m => (a -> m) -> ZipList a -> m # foldr :: (a -> b -> b) -> b -> ZipList a -> b # foldr' :: (a -> b -> b) -> b -> ZipList a -> b # foldl :: (b -> a -> b) -> b -> ZipList a -> b # foldl' :: (b -> a -> b) -> b -> ZipList a -> b # foldr1 :: (a -> a -> a) -> ZipList a -> a # foldl1 :: (a -> a -> a) -> ZipList a -> a # toList :: ZipList a -> [a] # null :: ZipList a -> Bool # length :: ZipList a -> Int # elem :: Eq a => a -> ZipList a -> Bool # maximum :: Ord a => ZipList a -> a # minimum :: Ord a => ZipList a -> a # sum :: Num a => ZipList a -> a # product :: Num a => ZipList a -> a #
Traversable ZipList	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> ZipList a -> f (ZipList b) # sequenceA :: Applicative f => ZipList (f a) -> f (ZipList a) # mapM :: Monad m => (a -> m b) -> ZipList a -> m (ZipList b) # sequence :: Monad m => ZipList (m a) -> m (ZipList a) #
Alternative ZipList	Since: base-4.11.0.0
Instance details Defined in Control.Applicative Methods empty :: ZipList a # (<\|>) :: ZipList a -> ZipList a -> ZipList a # some :: ZipList a -> ZipList [a] # many :: ZipList a -> ZipList [a] #
IsList (ZipList a)	Since: base-4.15.0.0
Instance details Defined in GHC.Exts Associated Types type Item (ZipList a) # Methods fromList :: [Item (ZipList a)] -> ZipList a # fromListN :: Int -> [Item (ZipList a)] -> ZipList a # toList :: ZipList a -> [Item (ZipList a)] #
Eq a => Eq (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods (==) :: ZipList a -> ZipList a -> Bool # (/=) :: ZipList a -> ZipList a -> Bool #
Ord a => Ord (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods compare :: ZipList a -> ZipList a -> Ordering # (<) :: ZipList a -> ZipList a -> Bool # (<=) :: ZipList a -> ZipList a -> Bool # (>) :: ZipList a -> ZipList a -> Bool # (>=) :: ZipList a -> ZipList a -> Bool # max :: ZipList a -> ZipList a -> ZipList a # min :: ZipList a -> ZipList a -> ZipList a #
Read a => Read (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods readsPrec :: Int -> ReadS (ZipList a) # readList :: ReadS [ZipList a] # readPrec :: ReadPrec (ZipList a) # readListPrec :: ReadPrec [ZipList a] #
Show a => Show (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods showsPrec :: Int -> ZipList a -> ShowS # show :: ZipList a -> String # showList :: [ZipList a] -> ShowS #
Generic (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep (ZipList a) :: Type -> Type # Methods from :: ZipList a -> Rep (ZipList a) x # to :: Rep (ZipList a) x -> ZipList a #
Generic1 ZipList	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep1 ZipList :: k -> Type # Methods from1 :: forall (a :: k). ZipList a -> Rep1 ZipList a # to1 :: forall (a :: k). Rep1 ZipList a -> ZipList a #
type Rep (ZipList a)
Instance details Defined in Control.Applicative type Rep (ZipList a) = D1 ('MetaData "ZipList" "Control.Applicative" "base" 'True) (C1 ('MetaCons "ZipList" 'PrefixI 'True) (S1 ('MetaSel ('Just "getZipList") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [a])))
type Item (ZipList a)
Instance details Defined in GHC.Exts type Item (ZipList a) = a
type Rep1 ZipList
Instance details Defined in Control.Applicative type Rep1 ZipList = D1 ('MetaData "ZipList" "Control.Applicative" "base" 'True) (C1 ('MetaCons "ZipList" 'PrefixI 'True) (S1 ('MetaSel ('Just "getZipList") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 [])))

(<**>) :: Applicative f => f a -> f (a -> b) -> f b infixl 4 #

A variant of <*> with the arguments reversed.

Using ApplicativeDo: 'as <**> fs' can be understood as the do expression

do a <- as
   f <- fs
   pure (f a)

liftA2 :: Applicative f => (a -> b -> c) -> f a -> f b -> f c #

Lift a binary function to actions.

Some functors support an implementation of liftA2 that is more efficient than the default one. In particular, if fmap is an expensive operation, it is likely better to use liftA2 than to fmap over the structure and then use <*>.

This became a typeclass method in 4.10.0.0. Prior to that, it was a function defined in terms of <*> and fmap.

Using ApplicativeDo: 'liftA2 f as bs' can be understood as the do expression

do a <- as
   b <- bs
   pure (f a b)

liftA3 :: Applicative f => (a -> b -> c -> d) -> f a -> f b -> f c -> f d #

Lift a ternary function to actions.

Using ApplicativeDo: 'liftA3 f as bs cs' can be understood as the do expression

do a <- as
   b <- bs
   c <- cs
   pure (f a b c)

pass :: Applicative f => f () Source #

() lifted to an Applicative.

pass = pure ()

Alternative

class Applicative f => Alternative (f :: Type -> Type) where #

A monoid on applicative functors.

If defined, some and many should be the least solutions of the equations:

```
some v = (:) <$> v <*> many v
```
```
many v = some v <|> pure []
```

Minimal complete definition

empty, (<|>)

Methods

empty :: f a #

The identity of <|>

(<|>) :: f a -> f a -> f a infixl 3 #

An associative binary operation

many :: f a -> f [a] #

Zero or more.

Instances

Instances details

Alternative []	Since: base-2.1
Instance details Defined in GHC.Base Methods empty :: [a] # (<\|>) :: [a] -> [a] -> [a] # some :: [a] -> [[a]] # many :: [a] -> [[a]] #
Alternative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods empty :: Maybe a # (<\|>) :: Maybe a -> Maybe a -> Maybe a # some :: Maybe a -> Maybe [a] # many :: Maybe a -> Maybe [a] #
Alternative IO	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods empty :: IO a # (<\|>) :: IO a -> IO a -> IO a # some :: IO a -> IO [a] # many :: IO a -> IO [a] #
Alternative Option	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods empty :: Option a # (<\|>) :: Option a -> Option a -> Option a # some :: Option a -> Option [a] # many :: Option a -> Option [a] #
Alternative ZipList	Since: base-4.11.0.0
Instance details Defined in Control.Applicative Methods empty :: ZipList a # (<\|>) :: ZipList a -> ZipList a -> ZipList a # some :: ZipList a -> ZipList [a] # many :: ZipList a -> ZipList [a] #
Alternative STM	Since: base-4.8.0.0
Instance details Defined in GHC.Conc.Sync Methods empty :: STM a # (<\|>) :: STM a -> STM a -> STM a # some :: STM a -> STM [a] # many :: STM a -> STM [a] #
Alternative ReadP	Since: base-4.6.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods empty :: ReadP a # (<\|>) :: ReadP a -> ReadP a -> ReadP a # some :: ReadP a -> ReadP [a] # many :: ReadP a -> ReadP [a] #
Alternative P	Since: base-4.5.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods empty :: P a # (<\|>) :: P a -> P a -> P a # some :: P a -> P [a] # many :: P a -> P [a] #
Alternative (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: U1 a # (<\|>) :: U1 a -> U1 a -> U1 a # some :: U1 a -> U1 [a] # many :: U1 a -> U1 [a] #
MonadPlus m => Alternative (WrappedMonad m)	Since: base-2.1
Instance details Defined in Control.Applicative Methods empty :: WrappedMonad m a # (<\|>) :: WrappedMonad m a -> WrappedMonad m a -> WrappedMonad m a # some :: WrappedMonad m a -> WrappedMonad m [a] # many :: WrappedMonad m a -> WrappedMonad m [a] #
ArrowPlus a => Alternative (ArrowMonad a)	Since: base-4.6.0.0
Instance details Defined in Control.Arrow Methods empty :: ArrowMonad a a0 # (<\|>) :: ArrowMonad a a0 -> ArrowMonad a a0 -> ArrowMonad a a0 # some :: ArrowMonad a a0 -> ArrowMonad a [a0] # many :: ArrowMonad a a0 -> ArrowMonad a [a0] #
Alternative (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Proxy Methods empty :: Proxy a # (<\|>) :: Proxy a -> Proxy a -> Proxy a # some :: Proxy a -> Proxy [a] # many :: Proxy a -> Proxy [a] #
Alternative f => Alternative (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: Rec1 f a # (<\|>) :: Rec1 f a -> Rec1 f a -> Rec1 f a # some :: Rec1 f a -> Rec1 f [a] # many :: Rec1 f a -> Rec1 f [a] #
(ArrowZero a, ArrowPlus a) => Alternative (WrappedArrow a b)	Since: base-2.1
Instance details Defined in Control.Applicative Methods empty :: WrappedArrow a b a0 # (<\|>) :: WrappedArrow a b a0 -> WrappedArrow a b a0 -> WrappedArrow a b a0 # some :: WrappedArrow a b a0 -> WrappedArrow a b [a0] # many :: WrappedArrow a b a0 -> WrappedArrow a b [a0] #
Alternative m => Alternative (Kleisli m a)	Since: base-4.14.0.0
Instance details Defined in Control.Arrow Methods empty :: Kleisli m a a0 # (<\|>) :: Kleisli m a a0 -> Kleisli m a a0 -> Kleisli m a a0 # some :: Kleisli m a a0 -> Kleisli m a [a0] # many :: Kleisli m a a0 -> Kleisli m a [a0] #
Alternative f => Alternative (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods empty :: Ap f a # (<\|>) :: Ap f a -> Ap f a -> Ap f a # some :: Ap f a -> Ap f [a] # many :: Ap f a -> Ap f [a] #
Alternative f => Alternative (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods empty :: Alt f a # (<\|>) :: Alt f a -> Alt f a -> Alt f a # some :: Alt f a -> Alt f [a] # many :: Alt f a -> Alt f [a] #
(Functor m, Monad m, Error e) => Alternative (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods empty :: ErrorT e m a # (<\|>) :: ErrorT e m a -> ErrorT e m a -> ErrorT e m a # some :: ErrorT e m a -> ErrorT e m [a] # many :: ErrorT e m a -> ErrorT e m [a] #
(Alternative f, Alternative g) => Alternative (f :*: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: (f :: g) a # (<\|>) :: (f :: g) a -> (f :: g) a -> (f :: g) a # some :: (f :: g) a -> (f :: g) [a] # many :: (f :: g) a -> (f :: g) [a] #
(Alternative f, Alternative g) => Alternative (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods empty :: Product f g a # (<\|>) :: Product f g a -> Product f g a -> Product f g a # some :: Product f g a -> Product f g [a] # many :: Product f g a -> Product f g [a] #
Alternative f => Alternative (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: M1 i c f a # (<\|>) :: M1 i c f a -> M1 i c f a -> M1 i c f a # some :: M1 i c f a -> M1 i c f [a] # many :: M1 i c f a -> M1 i c f [a] #
(Alternative f, Applicative g) => Alternative (f :.: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: (f :.: g) a # (<\|>) :: (f :.: g) a -> (f :.: g) a -> (f :.: g) a # some :: (f :.: g) a -> (f :.: g) [a] # many :: (f :.: g) a -> (f :.: g) [a] #
(Alternative f, Applicative g) => Alternative (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods empty :: Compose f g a # (<\|>) :: Compose f g a -> Compose f g a -> Compose f g a # some :: Compose f g a -> Compose f g [a] # many :: Compose f g a -> Compose f g [a] #

optional :: Alternative f => f a -> f (Maybe a) #

One or none.

some1 :: Alternative f => f a -> f (NonEmpty a) #

some1 x sequences x one or more times.

Monad

(<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c infixr 1 #

Right-to-left composition of Kleisli arrows. (>=>), with the arguments flipped.

Note how this operator resembles function composition (.):

(.)   ::            (b ->   c) -> (a ->   b) -> a ->   c
(<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c

(=<<) :: Monad m => (a -> m b) -> m a -> m b infixr 1 #

Same as >>=, but with the arguments interchanged.

(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c infixr 1 #

Left-to-right composition of Kleisli arrows.

'(bs >=> cs) a' can be understood as the do expression

do b <- bs a
   cs b

(>>) :: Monad m => m a -> m b -> m b infixl 1 #

Sequentially compose two actions, discarding any value produced by the first, like sequencing operators (such as the semicolon) in imperative languages.

'as >> bs' can be understood as the do expression

do as
   bs

(<$!>) :: Monad m => (a -> b) -> m a -> m b infixl 4 #

Strict version of <$>.

Since: base-4.8.0.0

ap :: Monad m => m (a -> b) -> m a -> m b #

In many situations, the liftM operations can be replaced by uses of ap, which promotes function application.

return f `ap` x1 `ap` ... `ap` xn

is equivalent to

liftMn f x1 x2 ... xn

(&&^) :: Monad m => m Bool -> m Bool -> m Bool #

(||^) :: Monad m => m Bool -> m Bool -> m Bool #

allM :: Monad m => (a -> m Bool) -> [a] -> m Bool #

andM :: Monad m => [m Bool] -> m Bool #

anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool #

concatMapM :: Monad m => (a -> m [b]) -> [a] -> m [b] #

ifM :: Monad m => m Bool -> m a -> m a -> m a #

orM :: Monad m => [m Bool] -> m Bool #

unlessM :: Monad m => m Bool -> m () -> m () #

whenM :: Monad m => m Bool -> m () -> m () #

filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a] #

This generalizes the list-based filter function.

class Monad m => MonadFix (m :: Type -> Type) where #

Monads having fixed points with a 'knot-tying' semantics. Instances of MonadFix should satisfy the following laws:

Purity: mfix (return . h) = return (fix h)
Left shrinking (or Tightening): mfix (\x -> a >>= \y -> f x y) = a >>= \y -> mfix (\x -> f x y)
Sliding: mfix (liftM h . f) = liftM h (mfix (f . h)), for strict h.
Nesting: mfix (\x -> mfix (\y -> f x y)) = mfix (\x -> f x x)

This class is used in the translation of the recursive do notation supported by GHC and Hugs.

Methods

mfix :: (a -> m a) -> m a #

The fixed point of a monadic computation. mfix f executes the action f only once, with the eventual output fed back as the input. Hence f should not be strict, for then mfix f would diverge.

Instances

Instances details

MonadFix []	Since: base-2.1
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> [a]) -> [a] #
MonadFix Maybe	Since: base-2.1
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Maybe a) -> Maybe a #
MonadFix IO	Since: base-2.1
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> IO a) -> IO a #
MonadFix Par1	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Par1 a) -> Par1 a #
MonadFix Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mfix :: (a -> Min a) -> Min a #
MonadFix Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mfix :: (a -> Max a) -> Max a #
MonadFix First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mfix :: (a -> First a) -> First a #
MonadFix Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mfix :: (a -> Last a) -> Last a #
MonadFix Option	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods mfix :: (a -> Option a) -> Option a #
MonadFix Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods mfix :: (a -> Identity a) -> Identity a #
MonadFix First	Since: base-4.8.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> First a) -> First a #
MonadFix Last	Since: base-4.8.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Last a) -> Last a #
MonadFix Dual	Since: base-4.8.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Dual a) -> Dual a #
MonadFix Sum	Since: base-4.8.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Sum a) -> Sum a #
MonadFix Product	Since: base-4.8.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Product a) -> Product a #
MonadFix Down	Since: base-4.12.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Down a) -> Down a #
MonadFix NonEmpty	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> NonEmpty a) -> NonEmpty a #
MonadFix (Either e)	Since: base-4.3.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Either e a) -> Either e a #
MonadFix (ST s)	Since: base-2.1
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> ST s a) -> ST s a #
MonadFix f => MonadFix (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Rec1 f a) -> Rec1 f a #
MonadFix f => MonadFix (Ap f)	Since: base-4.12.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Ap f a) -> Ap f a #
MonadFix f => MonadFix (Alt f)	Since: base-4.8.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> Alt f a) -> Alt f a #
(MonadFix m, Error e) => MonadFix (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods mfix :: (a -> ErrorT e m a) -> ErrorT e m a #
MonadFix ((->) r :: Type -> Type)	Since: base-2.1
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> r -> a) -> r -> a #
(MonadFix f, MonadFix g) => MonadFix (f :*: g)	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> (f :: g) a) -> (f :: g) a #
(MonadFix f, MonadFix g) => MonadFix (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods mfix :: (a -> Product f g a) -> Product f g a #
MonadFix f => MonadFix (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> M1 i c f a) -> M1 i c f a #

foldM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b #

The foldM function is analogous to foldl, except that its result is encapsulated in a monad. Note that foldM works from left-to-right over the list arguments. This could be an issue where (>>) and the `folded function' are not commutative.

foldM f a1 [x1, x2, ..., xm]

==

do
  a2 <- f a1 x1
  a3 <- f a2 x2
  ...
  f am xm

If right-to-left evaluation is required, the input list should be reversed.

Note: foldM is the same as foldlM

foldM_ :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m () #

Like foldM, but discards the result.

forever :: Applicative f => f a -> f b #

Repeat an action indefinitely.

Using ApplicativeDo: 'forever as' can be understood as the pseudo-do expression

do as
   as
   ..

with as repeating.

Examples

Expand

A common use of forever is to process input from network sockets, Handles, and channels (e.g. MVar and Chan).

For example, here is how we might implement an echo server, using forever both to listen for client connections on a network socket and to echo client input on client connection handles:

echoServer :: Socket -> IO ()
echoServer socket = forever $ do
  client <- accept socket
  forkFinally (echo client) (\_ -> hClose client)
  where
    echo :: Handle -> IO ()
    echo client = forever $
      hGetLine client >>= hPutStrLn client

guard :: Alternative f => Bool -> f () #

Conditional failure of Alternative computations. Defined by

guard True  = pure ()
guard False = empty

Examples

Expand

Common uses of guard include conditionally signaling an error in an error monad and conditionally rejecting the current choice in an Alternative-based parser.

As an example of signaling an error in the error monad Maybe, consider a safe division function safeDiv x y that returns Nothing when the denominator y is zero and Just (x `div` y) otherwise. For example:

>>> safeDiv 4 0
Nothing
>>> safeDiv 4 2
Just 2

A definition of safeDiv using guards, but not guard:

safeDiv :: Int -> Int -> Maybe Int
safeDiv x y | y /= 0    = Just (x `div` y)
            | otherwise = Nothing

A definition of safeDiv using guard and Monad do-notation:

safeDiv :: Int -> Int -> Maybe Int
safeDiv x y = do
  guard (y /= 0)
  return (x `div` y)

join :: Monad m => m (m a) -> m a #

The join function is the conventional monad join operator. It is used to remove one level of monadic structure, projecting its bound argument into the outer level.

'join bss' can be understood as the do expression

do bs <- bss
   bs

Examples

Expand

A common use of join is to run an IO computation returned from an STM transaction, since STM transactions can't perform IO directly. Recall that

atomically :: STM a -> IO a

is used to run STM transactions atomically. So, by specializing the types of atomically and join to

atomically :: STM (IO b) -> IO (IO b)
join       :: IO (IO b)  -> IO b

we can compose them as

join . atomically :: STM (IO b) -> IO b

to run an STM transaction and the IO action it returns.

liftM :: Monad m => (a1 -> r) -> m a1 -> m r #

Promote a function to a monad.

liftM2 :: Monad m => (a1 -> a2 -> r) -> m a1 -> m a2 -> m r #

Promote a function to a monad, scanning the monadic arguments from left to right. For example,

liftM2 (+) [0,1] [0,2] = [0,2,1,3]
liftM2 (+) (Just 1) Nothing = Nothing

liftM3 :: Monad m => (a1 -> a2 -> a3 -> r) -> m a1 -> m a2 -> m a3 -> m r #

Promote a function to a monad, scanning the monadic arguments from left to right (cf. liftM2).

liftM4 :: Monad m => (a1 -> a2 -> a3 -> a4 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m r #

Promote a function to a monad, scanning the monadic arguments from left to right (cf. liftM2).

liftM5 :: Monad m => (a1 -> a2 -> a3 -> a4 -> a5 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m a5 -> m r #

Promote a function to a monad, scanning the monadic arguments from left to right (cf. liftM2).

mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c]) #

The mapAndUnzipM function maps its first argument over a list, returning the result as a pair of lists. This function is mainly used with complicated data structures or a state monad.

mfilter :: MonadPlus m => (a -> Bool) -> m a -> m a #

Direct MonadPlus equivalent of filter.

Examples

Expand

The filter function is just mfilter specialized to the list monad:

filter = ( mfilter :: (a -> Bool) -> [a] -> [a] )

An example using mfilter with the Maybe monad:

>>> mfilter odd (Just 1)
Just 1
>>> mfilter odd (Just 2)
Nothing

class Applicative m => Monad (m :: Type -> Type) where #

The Monad class defines the basic operations over a monad, a concept from a branch of mathematics known as category theory. From the perspective of a Haskell programmer, however, it is best to think of a monad as an abstract datatype of actions. Haskell's do expressions provide a convenient syntax for writing monadic expressions.

Instances of Monad should satisfy the following:

Left identity: return a >>= k = k a
Right identity: m >>= return = m
Associativity: m >>= (\x -> k x >>= h) = (m >>= k) >>= h

Furthermore, the Monad and Applicative operations should relate as follows:

```
pure = return
```

m1 <*> m2 = m1 >>= (x1 -> m2 >>= (x2 -> return (x1 x2)))

The above laws imply:

```
fmap f xs  =  xs >>= return . f
```
```
(>>) = (*>)
```

and that pure and (<*>) satisfy the applicative functor laws.

The instances of Monad for lists, Maybe and IO defined in the Prelude satisfy these laws.

Methods

(>>=) :: m a -> (a -> m b) -> m b infixl 1 #

Sequentially compose two actions, passing any value produced by the first as an argument to the second.

'as >>= bs' can be understood as the do expression

do a <- as
   bs a

Instances

Instances details

Monad []	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: [a] -> (a -> [b]) -> [b] # (>>) :: [a] -> [b] -> [b] # return :: a -> [a] #
Monad Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b # (>>) :: Maybe a -> Maybe b -> Maybe b # return :: a -> Maybe a #
Monad IO	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: IO a -> (a -> IO b) -> IO b # (>>) :: IO a -> IO b -> IO b # return :: a -> IO a #
Monad Par1	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (>>=) :: Par1 a -> (a -> Par1 b) -> Par1 b # (>>) :: Par1 a -> Par1 b -> Par1 b # return :: a -> Par1 a #
Monad Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Min a -> (a -> Min b) -> Min b # (>>) :: Min a -> Min b -> Min b # return :: a -> Min a #
Monad Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Max a -> (a -> Max b) -> Max b # (>>) :: Max a -> Max b -> Max b # return :: a -> Max a #
Monad First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: First a -> (a -> First b) -> First b # (>>) :: First a -> First b -> First b # return :: a -> First a #
Monad Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Last a -> (a -> Last b) -> Last b # (>>) :: Last a -> Last b -> Last b # return :: a -> Last a #
Monad Option	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Option a -> (a -> Option b) -> Option b # (>>) :: Option a -> Option b -> Option b # return :: a -> Option a #
Monad Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods (>>=) :: Identity a -> (a -> Identity b) -> Identity b # (>>) :: Identity a -> Identity b -> Identity b # return :: a -> Identity a #
Monad STM	Since: base-4.3.0.0
Instance details Defined in GHC.Conc.Sync Methods (>>=) :: STM a -> (a -> STM b) -> STM b # (>>) :: STM a -> STM b -> STM b # return :: a -> STM a #
Monad First	Since: base-4.8.0.0
Instance details Defined in Data.Monoid Methods (>>=) :: First a -> (a -> First b) -> First b # (>>) :: First a -> First b -> First b # return :: a -> First a #
Monad Last	Since: base-4.8.0.0
Instance details Defined in Data.Monoid Methods (>>=) :: Last a -> (a -> Last b) -> Last b # (>>) :: Last a -> Last b -> Last b # return :: a -> Last a #
Monad Dual	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (>>=) :: Dual a -> (a -> Dual b) -> Dual b # (>>) :: Dual a -> Dual b -> Dual b # return :: a -> Dual a #
Monad Sum	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (>>=) :: Sum a -> (a -> Sum b) -> Sum b # (>>) :: Sum a -> Sum b -> Sum b # return :: a -> Sum a #
Monad Product	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (>>=) :: Product a -> (a -> Product b) -> Product b # (>>) :: Product a -> Product b -> Product b # return :: a -> Product a #
Monad Down	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods (>>=) :: Down a -> (a -> Down b) -> Down b # (>>) :: Down a -> Down b -> Down b # return :: a -> Down a #
Monad ReadP	Since: base-2.1
Instance details Defined in Text.ParserCombinators.ReadP Methods (>>=) :: ReadP a -> (a -> ReadP b) -> ReadP b # (>>) :: ReadP a -> ReadP b -> ReadP b # return :: a -> ReadP a #
Monad NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (>>=) :: NonEmpty a -> (a -> NonEmpty b) -> NonEmpty b # (>>) :: NonEmpty a -> NonEmpty b -> NonEmpty b # return :: a -> NonEmpty a #
Monad P	Since: base-2.1
Instance details Defined in Text.ParserCombinators.ReadP Methods (>>=) :: P a -> (a -> P b) -> P b # (>>) :: P a -> P b -> P b # return :: a -> P a #
Monad (Either e)	Since: base-4.4.0.0
Instance details Defined in Data.Either Methods (>>=) :: Either e a -> (a -> Either e b) -> Either e b # (>>) :: Either e a -> Either e b -> Either e b # return :: a -> Either e a #
Monad (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (>>=) :: U1 a -> (a -> U1 b) -> U1 b # (>>) :: U1 a -> U1 b -> U1 b # return :: a -> U1 a #
Monoid a => Monad ((,) a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods (>>=) :: (a, a0) -> (a0 -> (a, b)) -> (a, b) # (>>) :: (a, a0) -> (a, b) -> (a, b) # return :: a0 -> (a, a0) #
Monad m => Monad (WrappedMonad m)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods (>>=) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b # (>>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # return :: a -> WrappedMonad m a #
ArrowApply a => Monad (ArrowMonad a)	Since: base-2.1
Instance details Defined in Control.Arrow Methods (>>=) :: ArrowMonad a a0 -> (a0 -> ArrowMonad a b) -> ArrowMonad a b # (>>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b # return :: a0 -> ArrowMonad a a0 #
Monad (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods (>>=) :: Proxy a -> (a -> Proxy b) -> Proxy b # (>>) :: Proxy a -> Proxy b -> Proxy b # return :: a -> Proxy a #
Monad f => Monad (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (>>=) :: Rec1 f a -> (a -> Rec1 f b) -> Rec1 f b # (>>) :: Rec1 f a -> Rec1 f b -> Rec1 f b # return :: a -> Rec1 f a #
(Monoid a, Monoid b) => Monad ((,,) a b)	Since: base-4.14.0.0
Instance details Defined in GHC.Base Methods (>>=) :: (a, b, a0) -> (a0 -> (a, b, b0)) -> (a, b, b0) # (>>) :: (a, b, a0) -> (a, b, b0) -> (a, b, b0) # return :: a0 -> (a, b, a0) #
Monad m => Monad (Kleisli m a)	Since: base-4.14.0.0
Instance details Defined in Control.Arrow Methods (>>=) :: Kleisli m a a0 -> (a0 -> Kleisli m a b) -> Kleisli m a b # (>>) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a b # return :: a0 -> Kleisli m a a0 #
Monad f => Monad (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods (>>=) :: Ap f a -> (a -> Ap f b) -> Ap f b # (>>) :: Ap f a -> Ap f b -> Ap f b # return :: a -> Ap f a #
Monad f => Monad (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods (>>=) :: Alt f a -> (a -> Alt f b) -> Alt f b # (>>) :: Alt f a -> Alt f b -> Alt f b # return :: a -> Alt f a #
(Monad m, Error e) => Monad (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods (>>=) :: ErrorT e m a -> (a -> ErrorT e m b) -> ErrorT e m b # (>>) :: ErrorT e m a -> ErrorT e m b -> ErrorT e m b # return :: a -> ErrorT e m a #
Monad ((->) r :: Type -> Type)	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: (r -> a) -> (a -> r -> b) -> r -> b # (>>) :: (r -> a) -> (r -> b) -> r -> b # return :: a -> r -> a #
(Monad f, Monad g) => Monad (f :*: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (>>=) :: (f :: g) a -> (a -> (f :: g) b) -> (f :: g) b # (>>) :: (f :: g) a -> (f :: g) b -> (f :: g) b # return :: a -> (f :*: g) a #
(Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c)	Since: base-4.14.0.0
Instance details Defined in GHC.Base Methods (>>=) :: (a, b, c, a0) -> (a0 -> (a, b, c, b0)) -> (a, b, c, b0) # (>>) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, b0) # return :: a0 -> (a, b, c, a0) #
(Monad f, Monad g) => Monad (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods (>>=) :: Product f g a -> (a -> Product f g b) -> Product f g b # (>>) :: Product f g a -> Product f g b -> Product f g b # return :: a -> Product f g a #
(Applicative f, Monad f) => Monad (WhenMissing f k x)	Equivalent to `ReaderT k (ReaderT x (MaybeT f))` . Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods (>>=) :: WhenMissing f k x a -> (a -> WhenMissing f k x b) -> WhenMissing f k x b # (>>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # return :: a -> WhenMissing f k x a #
Monad f => Monad (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods (>>=) :: M1 i c f a -> (a -> M1 i c f b) -> M1 i c f b # (>>) :: M1 i c f a -> M1 i c f b -> M1 i c f b # return :: a -> M1 i c f a #
(Monad f, Applicative f) => Monad (WhenMatched f k x y)	Equivalent to `ReaderT k (ReaderT x (ReaderT y (MaybeT f)))` Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods (>>=) :: WhenMatched f k x y a -> (a -> WhenMatched f k x y b) -> WhenMatched f k x y b # (>>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # return :: a -> WhenMatched f k x y a #

replicateM :: Applicative m => Int -> m a -> m [a] #

replicateM n act performs the action n times, gathering the results.

Using ApplicativeDo: 'replicateM 5 as' can be understood as the do expression

do a1 <- as
   a2 <- as
   a3 <- as
   a4 <- as
   a5 <- as
   pure [a1,a2,a3,a4,a5]

Note the Applicative constraint.

replicateM_ :: Applicative m => Int -> m a -> m () #

Like replicateM, but discards the result.

unless :: Applicative f => Bool -> f () -> f () #

The reverse of when.

when :: Applicative f => Bool -> f () -> f () #

Conditional execution of Applicative expressions. For example,

when debug (putStrLn "Debugging")

will output the string Debugging if the Boolean value debug is True, and otherwise do nothing.

zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c] #

The zipWithM function generalizes zipWith to arbitrary applicative functors.

zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m () #

zipWithM_ is the extension of zipWithM which ignores the final result.

class (Typeable e, Show e) => Exception e #

Any type that you wish to throw or catch as an exception must be an instance of the Exception class. The simplest case is a new exception type directly below the root:

data MyException = ThisException | ThatException
    deriving Show

instance Exception MyException

The default method definitions in the Exception class do what we need in this case. You can now throw and catch ThisException and ThatException as exceptions:

*Main> throw ThisException `catch` \e -> putStrLn ("Caught " ++ show (e :: MyException))
Caught ThisException

In more complicated examples, you may wish to define a whole hierarchy of exceptions:

---------------------------------------------------------------------
-- Make the root exception type for all the exceptions in a compiler

data SomeCompilerException = forall e . Exception e => SomeCompilerException e

instance Show SomeCompilerException where
    show (SomeCompilerException e) = show e

instance Exception SomeCompilerException

compilerExceptionToException :: Exception e => e -> SomeException
compilerExceptionToException = toException . SomeCompilerException

compilerExceptionFromException :: Exception e => SomeException -> Maybe e
compilerExceptionFromException x = do
    SomeCompilerException a <- fromException x
    cast a

---------------------------------------------------------------------
-- Make a subhierarchy for exceptions in the frontend of the compiler

data SomeFrontendException = forall e . Exception e => SomeFrontendException e

instance Show SomeFrontendException where
    show (SomeFrontendException e) = show e

instance Exception SomeFrontendException where
    toException = compilerExceptionToException
    fromException = compilerExceptionFromException

frontendExceptionToException :: Exception e => e -> SomeException
frontendExceptionToException = toException . SomeFrontendException

frontendExceptionFromException :: Exception e => SomeException -> Maybe e
frontendExceptionFromException x = do
    SomeFrontendException a <- fromException x
    cast a

---------------------------------------------------------------------
-- Make an exception type for a particular frontend compiler exception

data MismatchedParentheses = MismatchedParentheses
    deriving Show

instance Exception MismatchedParentheses where
    toException   = frontendExceptionToException
    fromException = frontendExceptionFromException

We can now catch a MismatchedParentheses exception as MismatchedParentheses, SomeFrontendException or SomeCompilerException, but not other types, e.g. IOException:

*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: MismatchedParentheses))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeFrontendException))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeCompilerException))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: IOException))
*** Exception: MismatchedParentheses

Instances

Instances details

Exception Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Methods toException :: Void -> SomeException # fromException :: SomeException -> Maybe Void # displayException :: Void -> String #
Exception BlockedIndefinitelyOnMVar	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: BlockedIndefinitelyOnMVar -> SomeException # fromException :: SomeException -> Maybe BlockedIndefinitelyOnMVar # displayException :: BlockedIndefinitelyOnMVar -> String #
Exception BlockedIndefinitelyOnSTM	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: BlockedIndefinitelyOnSTM -> SomeException # fromException :: SomeException -> Maybe BlockedIndefinitelyOnSTM # displayException :: BlockedIndefinitelyOnSTM -> String #
Exception Deadlock	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: Deadlock -> SomeException # fromException :: SomeException -> Maybe Deadlock # displayException :: Deadlock -> String #
Exception AllocationLimitExceeded	Since: base-4.8.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: AllocationLimitExceeded -> SomeException # fromException :: SomeException -> Maybe AllocationLimitExceeded # displayException :: AllocationLimitExceeded -> String #
Exception CompactionFailed	Since: base-4.10.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: CompactionFailed -> SomeException # fromException :: SomeException -> Maybe CompactionFailed # displayException :: CompactionFailed -> String #
Exception AssertionFailed	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: AssertionFailed -> SomeException # fromException :: SomeException -> Maybe AssertionFailed # displayException :: AssertionFailed -> String #
Exception SomeAsyncException	Since: base-4.7.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: SomeAsyncException -> SomeException # fromException :: SomeException -> Maybe SomeAsyncException # displayException :: SomeAsyncException -> String #
Exception AsyncException	Since: base-4.7.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: AsyncException -> SomeException # fromException :: SomeException -> Maybe AsyncException # displayException :: AsyncException -> String #
Exception ArrayException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: ArrayException -> SomeException # fromException :: SomeException -> Maybe ArrayException # displayException :: ArrayException -> String #
Exception FixIOException	Since: base-4.11.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: FixIOException -> SomeException # fromException :: SomeException -> Maybe FixIOException # displayException :: FixIOException -> String #
Exception ExitCode	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: ExitCode -> SomeException # fromException :: SomeException -> Maybe ExitCode # displayException :: ExitCode -> String #
Exception IOException	Since: base-4.1.0.0
Instance details Defined in GHC.IO.Exception Methods toException :: IOException -> SomeException # fromException :: SomeException -> Maybe IOException # displayException :: IOException -> String #
Exception ArithException	Since: base-4.0.0.0
Instance details Defined in GHC.Exception.Type Methods toException :: ArithException -> SomeException # fromException :: SomeException -> Maybe ArithException # displayException :: ArithException -> String #
Exception SomeException	Since: base-3.0
Instance details Defined in GHC.Exception.Type Methods toException :: SomeException -> SomeException # fromException :: SomeException -> Maybe SomeException # displayException :: SomeException -> String #
Exception UnicodeException
Instance details Defined in Data.Text.Encoding.Error Methods toException :: UnicodeException -> SomeException # fromException :: SomeException -> Maybe UnicodeException # displayException :: UnicodeException -> String #

data SomeException #

The SomeException type is the root of the exception type hierarchy. When an exception of type e is thrown, behind the scenes it is encapsulated in a SomeException.

Instances

Instances details

Show SomeException	Since: base-3.0
Instance details Defined in GHC.Exception.Type Methods showsPrec :: Int -> SomeException -> ShowS # show :: SomeException -> String # showList :: [SomeException] -> ShowS #
Exception SomeException	Since: base-3.0
Instance details Defined in GHC.Exception.Type Methods toException :: SomeException -> SomeException # fromException :: SomeException -> Maybe SomeException # displayException :: SomeException -> String #

Bifunctor

class Bifunctor (p :: Type -> Type -> Type) where #

A bifunctor is a type constructor that takes two type arguments and is a functor in both arguments. That is, unlike with Functor, a type constructor such as Either does not need to be partially applied for a Bifunctor instance, and the methods in this class permit mapping functions over the Left value or the Right value, or both at the same time.

Formally, the class Bifunctor represents a bifunctor from Hask -> Hask.

Intuitively it is a bifunctor where both the first and second arguments are covariant.

You can define a Bifunctor by either defining bimap or by defining both first and second.

If you supply bimap, you should ensure that:

bimap id id ≡ id

If you supply first and second, ensure:

first id ≡ id
second id ≡ id

If you supply both, you should also ensure:

bimap f g ≡ first f . second g

These ensure by parametricity:

bimap  (f . g) (h . i) ≡ bimap f h . bimap g i
first  (f . g) ≡ first  f . first  g
second (f . g) ≡ second f . second g

Since: base-4.8.0.0

Minimal complete definition

bimap | first, second

Methods

bimap :: (a -> b) -> (c -> d) -> p a c -> p b d #

Map over both arguments at the same time.

bimap f g ≡ first f . second g

Examples

Expand

>>> bimap toUpper (+1) ('j', 3)
('J',4)

>>> bimap toUpper (+1) (Left 'j')
Left 'J'

>>> bimap toUpper (+1) (Right 3)
Right 4

first :: (a -> b) -> p a c -> p b c #

Map covariantly over the first argument.

first f ≡ bimap f id

Examples

Expand

>>> first toUpper ('j', 3)
('J',3)

>>> first toUpper (Left 'j')
Left 'J'

second :: (b -> c) -> p a b -> p a c #

Map covariantly over the second argument.

second ≡ bimap id

Examples

Expand

>>> second (+1) ('j', 3)
('j',4)

>>> second (+1) (Right 3)
Right 4

Instances

Instances details

Bifunctor Either	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> Either a c -> Either b d # first :: (a -> b) -> Either a c -> Either b c # second :: (b -> c) -> Either a b -> Either a c #
Bifunctor (,)	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> (a, c) -> (b, d) # first :: (a -> b) -> (a, c) -> (b, c) # second :: (b -> c) -> (a, b) -> (a, c) #
Bifunctor Arg	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods bimap :: (a -> b) -> (c -> d) -> Arg a c -> Arg b d # first :: (a -> b) -> Arg a c -> Arg b c # second :: (b -> c) -> Arg a b -> Arg a c #
Bifunctor ((,,) x1)	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> (x1, a, c) -> (x1, b, d) # first :: (a -> b) -> (x1, a, c) -> (x1, b, c) # second :: (b -> c) -> (x1, a, b) -> (x1, a, c) #
Bifunctor (Const :: Type -> Type -> Type)	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> Const a c -> Const b d # first :: (a -> b) -> Const a c -> Const b c # second :: (b -> c) -> Const a b -> Const a c #
Bifunctor (K1 i :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> K1 i a c -> K1 i b d # first :: (a -> b) -> K1 i a c -> K1 i b c # second :: (b -> c) -> K1 i a b -> K1 i a c #
Bifunctor ((,,,) x1 x2)	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> (x1, x2, a, c) -> (x1, x2, b, d) # first :: (a -> b) -> (x1, x2, a, c) -> (x1, x2, b, c) # second :: (b -> c) -> (x1, x2, a, b) -> (x1, x2, a, c) #
Bifunctor ((,,,,) x1 x2 x3)	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> (x1, x2, x3, a, c) -> (x1, x2, x3, b, d) # first :: (a -> b) -> (x1, x2, x3, a, c) -> (x1, x2, x3, b, c) # second :: (b -> c) -> (x1, x2, x3, a, b) -> (x1, x2, x3, a, c) #
Bifunctor ((,,,,,) x1 x2 x3 x4)	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> (x1, x2, x3, x4, a, c) -> (x1, x2, x3, x4, b, d) # first :: (a -> b) -> (x1, x2, x3, x4, a, c) -> (x1, x2, x3, x4, b, c) # second :: (b -> c) -> (x1, x2, x3, x4, a, b) -> (x1, x2, x3, x4, a, c) #
Bifunctor ((,,,,,,) x1 x2 x3 x4 x5)	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> (x1, x2, x3, x4, x5, a, c) -> (x1, x2, x3, x4, x5, b, d) # first :: (a -> b) -> (x1, x2, x3, x4, x5, a, c) -> (x1, x2, x3, x4, x5, b, c) # second :: (b -> c) -> (x1, x2, x3, x4, x5, a, b) -> (x1, x2, x3, x4, x5, a, c) #

Bifoldable

class Bifoldable (p :: Type -> Type -> Type) where #

Bifoldable identifies foldable structures with two different varieties of elements (as opposed to Foldable, which has one variety of element). Common examples are Either and (,):

instance Bifoldable Either where
  bifoldMap f _ (Left  a) = f a
  bifoldMap _ g (Right b) = g b

instance Bifoldable (,) where
  bifoldr f g z (a, b) = f a (g b z)

A minimal Bifoldable definition consists of either bifoldMap or bifoldr. When defining more than this minimal set, one should ensure that the following identities hold:

bifold ≡ bifoldMap id id
bifoldMap f g ≡ bifoldr (mappend . f) (mappend . g) mempty
bifoldr f g z t ≡ appEndo (bifoldMap (Endo . f) (Endo . g) t) z

If the type is also a Bifunctor instance, it should satisfy:

bifoldMap f g ≡ bifold . bimap f g

which implies that

bifoldMap f g . bimap h i ≡ bifoldMap (f . h) (g . i)

Since: base-4.10.0.0

Minimal complete definition

bifoldr | bifoldMap

Methods

bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> p a b -> m #

Combines the elements of a structure, given ways of mapping them to a common monoid.

bifoldMap f g
     ≡ bifoldr (mappend . f) (mappend . g) mempty

Since: base-4.10.0.0

bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> p a b -> c #

Combines the elements of a structure in a right associative manner. Given a hypothetical function toEitherList :: p a b -> [Either a b] yielding a list of all elements of a structure in order, the following would hold:

bifoldr f g z ≡ foldr (either f g) z . toEitherList

Since: base-4.10.0.0

Instances

Instances details

Bifoldable Either	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => Either m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Either a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Either a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Either a b -> c #
Bifoldable (,)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => (m, m) -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> (a, b) -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> (a, b) -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> (a, b) -> c #
Bifoldable Arg	Since: base-4.10.0.0
Instance details Defined in Data.Semigroup Methods bifold :: Monoid m => Arg m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Arg a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Arg a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Arg a b -> c #
Bifoldable Map	Since: containers-0.6.3.1
Instance details Defined in Data.Map.Internal Methods bifold :: Monoid m => Map m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Map a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Map a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Map a b -> c #
Bifoldable ((,,) x)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => (x, m, m) -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> (x, a, b) -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> (x, a, b) -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> (x, a, b) -> c #
Bifoldable (Const :: Type -> Type -> Type)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => Const m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Const a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Const a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Const a b -> c #
Bifoldable (K1 i :: Type -> Type -> Type)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => K1 i m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> K1 i a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> K1 i a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> K1 i a b -> c #
Bifoldable ((,,,) x y)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => (x, y, m, m) -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> (x, y, a, b) -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> (x, y, a, b) -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> (x, y, a, b) -> c #
Bifoldable ((,,,,) x y z)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => (x, y, z, m, m) -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> (x, y, z, a, b) -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> (x, y, z, a, b) -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> (x, y, z, a, b) -> c #
Bifoldable ((,,,,,) x y z w)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => (x, y, z, w, m, m) -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> (x, y, z, w, a, b) -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> (x, y, z, w, a, b) -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> (x, y, z, w, a, b) -> c #
Bifoldable ((,,,,,,) x y z w v)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => (x, y, z, w, v, m, m) -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> (x, y, z, w, v, a, b) -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> (x, y, z, w, v, a, b) -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> (x, y, z, w, v, a, b) -> c #

bifoldl' :: Bifoldable t => (a -> b -> a) -> (a -> c -> a) -> a -> t b c -> a #

As bifoldl, but strict in the result of the reduction functions at each step.

This ensures that each step of the bifold is forced to weak head normal form before being applied, avoiding the collection of thunks that would otherwise occur. This is often what you want to strictly reduce a finite structure to a single, monolithic result (e.g., bilength).

Since: base-4.10.0.0

bifoldr' :: Bifoldable t => (a -> c -> c) -> (b -> c -> c) -> c -> t a b -> c #

As bifoldr, but strict in the result of the reduction functions at each step.

Since: base-4.10.0.0

bitraverse_ :: (Bifoldable t, Applicative f) => (a -> f c) -> (b -> f d) -> t a b -> f () #

Map each element of a structure using one of two actions, evaluate these actions from left to right, and ignore the results. For a version that doesn't ignore the results, see bitraverse.

Since: base-4.10.0.0

bisequenceA_ :: (Bifoldable t, Applicative f) => t (f a) (f b) -> f () #

Alias for bisequence_.

Since: base-4.10.0.0

bifor_ :: (Bifoldable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f () #

As bitraverse_, but with the structure as the primary argument. For a version that doesn't ignore the results, see bifor.

>>> > bifor_ ('a', "bc") print (print . reverse)
'a'
"cb"

Since: base-4.10.0.0

Bitraversable

class (Bifunctor t, Bifoldable t) => Bitraversable (t :: Type -> Type -> Type) where #

Bitraversable identifies bifunctorial data structures whose elements can be traversed in order, performing Applicative or Monad actions at each element, and collecting a result structure with the same shape.

As opposed to Traversable data structures, which have one variety of element on which an action can be performed, Bitraversable data structures have two such varieties of elements.

A definition of bitraverse must satisfy the following laws:

Naturality: bitraverse (t . f) (t . g) ≡ t . bitraverse f g for every applicative transformation t
Identity: bitraverse Identity Identity ≡ Identity
Composition: Compose . fmap (bitraverse g1 g2) . bitraverse f1 f2 ≡ bitraverse (Compose . fmap g1 . f1) (Compose . fmap g2 . f2)

where an applicative transformation is a function

t :: (Applicative f, Applicative g) => f a -> g a

preserving the Applicative operations:

t (pure x) = pure x
t (f <*> x) = t f <*> t x

and the identity functor Identity and composition functors Compose are from Data.Functor.Identity and Data.Functor.Compose.

Some simple examples are Either and (,):

instance Bitraversable Either where
  bitraverse f _ (Left x) = Left <$> f x
  bitraverse _ g (Right y) = Right <$> g y

instance Bitraversable (,) where
  bitraverse f g (x, y) = (,) <$> f x <*> g y

Bitraversable relates to its superclasses in the following ways:

bimap f g ≡ runIdentity . bitraverse (Identity . f) (Identity . g)
bifoldMap f g = getConst . bitraverse (Const . f) (Const . g)

These are available as bimapDefault and bifoldMapDefault respectively.

Since: base-4.10.0.0

Minimal complete definition

Nothing

Methods

bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> t a b -> f (t c d) #

Evaluates the relevant functions at each element in the structure, running the action, and builds a new structure with the same shape, using the results produced from sequencing the actions.

bitraverse f g ≡ bisequenceA . bimap f g

For a version that ignores the results, see bitraverse_.

Since: base-4.10.0.0

Instances

Instances details

Bitraversable Either	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Either a b -> f (Either c d) #
Bitraversable (,)	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (a, b) -> f (c, d) #
Bitraversable Arg	Since: base-4.10.0.0
Instance details Defined in Data.Semigroup Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Arg a b -> f (Arg c d) #
Bitraversable ((,,) x)	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, a, b) -> f (x, c, d) #
Bitraversable (Const :: Type -> Type -> Type)	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Const a b -> f (Const c d) #
Bitraversable (K1 i :: Type -> Type -> Type)	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> K1 i a b -> f (K1 i c d) #
Bitraversable ((,,,) x y)	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, y, a, b) -> f (x, y, c, d) #
Bitraversable ((,,,,) x y z)	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, y, z, a, b) -> f (x, y, z, c, d) #
Bitraversable ((,,,,,) x y z w)	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, y, z, w, a, b) -> f (x, y, z, w, c, d) #
Bitraversable ((,,,,,,) x y z w v)	Since: base-4.10.0.0
Instance details Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, y, z, w, v, a, b) -> f (x, y, z, w, v, c, d) #

bifor :: (Bitraversable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f (t c d) #

bifor is bitraverse with the structure as the first argument. For a version that ignores the results, see bifor_.

Since: base-4.10.0.0

bisequenceA :: (Bitraversable t, Applicative f) => t (f a) (f b) -> f (t a b) #

Alias for bisequence.

Since: base-4.10.0.0

Effects and monad transformers

class MonadTrans (t :: (Type -> Type) -> Type -> Type) where #

The class of monad transformers. Instances should satisfy the following laws, which state that lift is a monad transformation:

```
lift . return = return
```
```
lift (m >>= f) = lift m >>= (lift . f)
```

Methods

lift :: Monad m => m a -> t m a #

Lift a computation from the argument monad to the constructed monad.

Instances

Instances details

MonadTrans (ErrorT e)
Instance details Defined in Control.Monad.Trans.Error Methods lift :: Monad m => m a -> ErrorT e m a #

data ThreadId #

A ThreadId is an abstract type representing a handle to a thread. ThreadId is an instance of Eq, Ord and Show, where the Ord instance implements an arbitrary total ordering over ThreadIds. The Show instance lets you convert an arbitrary-valued ThreadId to string form; showing a ThreadId value is occasionally useful when debugging or diagnosing the behaviour of a concurrent program.

Note: in GHC, if you have a ThreadId, you essentially have a pointer to the thread itself. This means the thread itself can't be garbage collected until you drop the ThreadId. This misfeature will hopefully be corrected at a later date.

Instances

Instances details

Eq ThreadId	Since: base-4.2.0.0
Instance details Defined in GHC.Conc.Sync Methods (==) :: ThreadId -> ThreadId -> Bool # (/=) :: ThreadId -> ThreadId -> Bool #
Ord ThreadId	Since: base-4.2.0.0
Instance details Defined in GHC.Conc.Sync Methods compare :: ThreadId -> ThreadId -> Ordering # (<) :: ThreadId -> ThreadId -> Bool # (<=) :: ThreadId -> ThreadId -> Bool # (>) :: ThreadId -> ThreadId -> Bool # (>=) :: ThreadId -> ThreadId -> Bool # max :: ThreadId -> ThreadId -> ThreadId # min :: ThreadId -> ThreadId -> ThreadId #
Show ThreadId	Since: base-4.2.0.0
Instance details Defined in GHC.Conc.Sync Methods showsPrec :: Int -> ThreadId -> ShowS # show :: ThreadId -> String # showList :: [ThreadId] -> ShowS #

forkIO :: IO () -> IO ThreadId #

Creates a new thread to run the IO computation passed as the first argument, and returns the ThreadId of the newly created thread.

The new thread will be a lightweight, unbound thread. Foreign calls made by this thread are not guaranteed to be made by any particular OS thread; if you need foreign calls to be made by a particular OS thread, then use forkOS instead.

The new thread inherits the masked state of the parent (see mask).

The newly created thread has an exception handler that discards the exceptions BlockedIndefinitelyOnMVar, BlockedIndefinitelyOnSTM, and ThreadKilled, and passes all other exceptions to the uncaught exception handler.

forkFinally :: IO a -> (Either SomeException a -> IO ()) -> IO ThreadId #

Fork a thread and call the supplied function when the thread is about to terminate, with an exception or a returned value. The function is called with asynchronous exceptions masked.

forkFinally action and_then =
  mask $ \restore ->
    forkIO $ try (restore action) >>= and_then

This function is useful for informing the parent when a child terminates, for example.

Since: base-4.6.0.0

threadDelay :: Int -> IO () #

Suspends the current thread for a given number of microseconds (GHC only).

There is no guarantee that the thread will be rescheduled promptly when the delay has expired, but the thread will never continue to run earlier than specified.

myThreadId :: IO ThreadId #

Returns the ThreadId of the calling thread (GHC only).

Generic type classes

class Generic a #

Representable types of kind *. This class is derivable in GHC with the DeriveGeneric flag on.

A Generic instance must satisfy the following laws:

from . to ≡ id
to . from ≡ id

Minimal complete definition

from, to

Instances

Instances details

Generic Bool	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep Bool :: Type -> Type # Methods from :: Bool -> Rep Bool x # to :: Rep Bool x -> Bool #
Generic Ordering	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep Ordering :: Type -> Type # Methods from :: Ordering -> Rep Ordering x # to :: Rep Ordering x -> Ordering #
Generic ()	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep () :: Type -> Type # Methods from :: () -> Rep () x # to :: Rep () x -> () #
Generic Void	Since: base-4.8.0.0
Instance details Defined in Data.Void Associated Types type Rep Void :: Type -> Type # Methods from :: Void -> Rep Void x # to :: Rep Void x -> Void #
Generic ExitCode
Instance details Defined in GHC.IO.Exception Associated Types type Rep ExitCode :: Type -> Type # Methods from :: ExitCode -> Rep ExitCode x # to :: Rep ExitCode x -> ExitCode #
Generic All	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep All :: Type -> Type # Methods from :: All -> Rep All x # to :: Rep All x -> All #
Generic Any	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep Any :: Type -> Type # Methods from :: Any -> Rep Any x # to :: Rep Any x -> Any #
Generic Fixity	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep Fixity :: Type -> Type # Methods from :: Fixity -> Rep Fixity x # to :: Rep Fixity x -> Fixity #
Generic Associativity	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep Associativity :: Type -> Type # Methods from :: Associativity -> Rep Associativity x # to :: Rep Associativity x -> Associativity #
Generic SourceUnpackedness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep SourceUnpackedness :: Type -> Type # Methods from :: SourceUnpackedness -> Rep SourceUnpackedness x # to :: Rep SourceUnpackedness x -> SourceUnpackedness #
Generic SourceStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep SourceStrictness :: Type -> Type # Methods from :: SourceStrictness -> Rep SourceStrictness x # to :: Rep SourceStrictness x -> SourceStrictness #
Generic DecidedStrictness	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep DecidedStrictness :: Type -> Type # Methods from :: DecidedStrictness -> Rep DecidedStrictness x # to :: Rep DecidedStrictness x -> DecidedStrictness #
Generic [a]	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep [a] :: Type -> Type # Methods from :: [a] -> Rep [a] x # to :: Rep [a] x -> [a] #
Generic (Maybe a)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Maybe a) :: Type -> Type # Methods from :: Maybe a -> Rep (Maybe a) x # to :: Rep (Maybe a) x -> Maybe a #
Generic (Par1 p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Par1 p) :: Type -> Type # Methods from :: Par1 p -> Rep (Par1 p) x # to :: Rep (Par1 p) x -> Par1 p #
Generic (Min a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (Min a) :: Type -> Type # Methods from :: Min a -> Rep (Min a) x # to :: Rep (Min a) x -> Min a #
Generic (Max a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (Max a) :: Type -> Type # Methods from :: Max a -> Rep (Max a) x # to :: Rep (Max a) x -> Max a #
Generic (First a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (First a) :: Type -> Type # Methods from :: First a -> Rep (First a) x # to :: Rep (First a) x -> First a #
Generic (Last a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (Last a) :: Type -> Type # Methods from :: Last a -> Rep (Last a) x # to :: Rep (Last a) x -> Last a #
Generic (WrappedMonoid m)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (WrappedMonoid m) :: Type -> Type # Methods from :: WrappedMonoid m -> Rep (WrappedMonoid m) x # to :: Rep (WrappedMonoid m) x -> WrappedMonoid m #
Generic (Option a)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (Option a) :: Type -> Type # Methods from :: Option a -> Rep (Option a) x # to :: Rep (Option a) x -> Option a #
Generic (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep (ZipList a) :: Type -> Type # Methods from :: ZipList a -> Rep (ZipList a) x # to :: Rep (ZipList a) x -> ZipList a #
Generic (Identity a)	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Associated Types type Rep (Identity a) :: Type -> Type # Methods from :: Identity a -> Rep (Identity a) x # to :: Rep (Identity a) x -> Identity a #
Generic (First a)	Since: base-4.7.0.0
Instance details Defined in Data.Monoid Associated Types type Rep (First a) :: Type -> Type # Methods from :: First a -> Rep (First a) x # to :: Rep (First a) x -> First a #
Generic (Last a)	Since: base-4.7.0.0
Instance details Defined in Data.Monoid Associated Types type Rep (Last a) :: Type -> Type # Methods from :: Last a -> Rep (Last a) x # to :: Rep (Last a) x -> Last a #
Generic (Dual a)	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep (Dual a) :: Type -> Type # Methods from :: Dual a -> Rep (Dual a) x # to :: Rep (Dual a) x -> Dual a #
Generic (Endo a)	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep (Endo a) :: Type -> Type # Methods from :: Endo a -> Rep (Endo a) x # to :: Rep (Endo a) x -> Endo a #
Generic (Sum a)	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep (Sum a) :: Type -> Type # Methods from :: Sum a -> Rep (Sum a) x # to :: Rep (Sum a) x -> Sum a #
Generic (Product a)	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep (Product a) :: Type -> Type # Methods from :: Product a -> Rep (Product a) x # to :: Rep (Product a) x -> Product a #
Generic (Down a)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Down a) :: Type -> Type # Methods from :: Down a -> Rep (Down a) x # to :: Rep (Down a) x -> Down a #
Generic (NonEmpty a)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (NonEmpty a) :: Type -> Type # Methods from :: NonEmpty a -> Rep (NonEmpty a) x # to :: Rep (NonEmpty a) x -> NonEmpty a #
Generic (Either a b)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Either a b) :: Type -> Type # Methods from :: Either a b -> Rep (Either a b) x # to :: Rep (Either a b) x -> Either a b #
Generic (V1 p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (V1 p) :: Type -> Type # Methods from :: V1 p -> Rep (V1 p) x # to :: Rep (V1 p) x -> V1 p #
Generic (U1 p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (U1 p) :: Type -> Type # Methods from :: U1 p -> Rep (U1 p) x # to :: Rep (U1 p) x -> U1 p #
Generic (a, b)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (a, b) :: Type -> Type # Methods from :: (a, b) -> Rep (a, b) x # to :: Rep (a, b) x -> (a, b) #
Generic (Arg a b)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep (Arg a b) :: Type -> Type # Methods from :: Arg a b -> Rep (Arg a b) x # to :: Rep (Arg a b) x -> Arg a b #
Generic (WrappedMonad m a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep (WrappedMonad m a) :: Type -> Type # Methods from :: WrappedMonad m a -> Rep (WrappedMonad m a) x # to :: Rep (WrappedMonad m a) x -> WrappedMonad m a #
Generic (Proxy t)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Proxy t) :: Type -> Type # Methods from :: Proxy t -> Rep (Proxy t) x # to :: Rep (Proxy t) x -> Proxy t #
Generic (Rec1 f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Rec1 f p) :: Type -> Type # Methods from :: Rec1 f p -> Rep (Rec1 f p) x # to :: Rep (Rec1 f p) x -> Rec1 f p #
Generic (URec (Ptr ()) p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (URec (Ptr ()) p) :: Type -> Type # Methods from :: URec (Ptr ()) p -> Rep (URec (Ptr ()) p) x # to :: Rep (URec (Ptr ()) p) x -> URec (Ptr ()) p #
Generic (URec Char p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (URec Char p) :: Type -> Type # Methods from :: URec Char p -> Rep (URec Char p) x # to :: Rep (URec Char p) x -> URec Char p #
Generic (URec Double p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (URec Double p) :: Type -> Type # Methods from :: URec Double p -> Rep (URec Double p) x # to :: Rep (URec Double p) x -> URec Double p #
Generic (URec Float p)
Instance details Defined in GHC.Generics Associated Types type Rep (URec Float p) :: Type -> Type # Methods from :: URec Float p -> Rep (URec Float p) x # to :: Rep (URec Float p) x -> URec Float p #
Generic (URec Int p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (URec Int p) :: Type -> Type # Methods from :: URec Int p -> Rep (URec Int p) x # to :: Rep (URec Int p) x -> URec Int p #
Generic (URec Word p)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (URec Word p) :: Type -> Type # Methods from :: URec Word p -> Rep (URec Word p) x # to :: Rep (URec Word p) x -> URec Word p #
Generic (a, b, c)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (a, b, c) :: Type -> Type # Methods from :: (a, b, c) -> Rep (a, b, c) x # to :: Rep (a, b, c) x -> (a, b, c) #
Generic (WrappedArrow a b c)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep (WrappedArrow a b c) :: Type -> Type # Methods from :: WrappedArrow a b c -> Rep (WrappedArrow a b c) x # to :: Rep (WrappedArrow a b c) x -> WrappedArrow a b c #
Generic (Kleisli m a b)	Since: base-4.14.0.0
Instance details Defined in Control.Arrow Associated Types type Rep (Kleisli m a b) :: Type -> Type # Methods from :: Kleisli m a b -> Rep (Kleisli m a b) x # to :: Rep (Kleisli m a b) x -> Kleisli m a b #
Generic (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Associated Types type Rep (Const a b) :: Type -> Type # Methods from :: Const a b -> Rep (Const a b) x # to :: Rep (Const a b) x -> Const a b #
Generic (Ap f a)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Associated Types type Rep (Ap f a) :: Type -> Type # Methods from :: Ap f a -> Rep (Ap f a) x # to :: Rep (Ap f a) x -> Ap f a #
Generic (Alt f a)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep (Alt f a) :: Type -> Type # Methods from :: Alt f a -> Rep (Alt f a) x # to :: Rep (Alt f a) x -> Alt f a #
Generic (K1 i c p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (K1 i c p) :: Type -> Type # Methods from :: K1 i c p -> Rep (K1 i c p) x # to :: Rep (K1 i c p) x -> K1 i c p #
Generic ((f :+: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep ((f :+: g) p) :: Type -> Type # Methods from :: (f :+: g) p -> Rep ((f :+: g) p) x # to :: Rep ((f :+: g) p) x -> (f :+: g) p #
Generic ((f :*: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep ((f :: g) p) :: Type -> Type # Methods from :: (f :: g) p -> Rep ((f :: g) p) x # to :: Rep ((f :: g) p) x -> (f :*: g) p #
Generic (a, b, c, d)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (a, b, c, d) :: Type -> Type # Methods from :: (a, b, c, d) -> Rep (a, b, c, d) x # to :: Rep (a, b, c, d) x -> (a, b, c, d) #
Generic (Product f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Associated Types type Rep (Product f g a) :: Type -> Type # Methods from :: Product f g a -> Rep (Product f g a) x # to :: Rep (Product f g a) x -> Product f g a #
Generic (Sum f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Associated Types type Rep (Sum f g a) :: Type -> Type # Methods from :: Sum f g a -> Rep (Sum f g a) x # to :: Rep (Sum f g a) x -> Sum f g a #
Generic (M1 i c f p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (M1 i c f p) :: Type -> Type # Methods from :: M1 i c f p -> Rep (M1 i c f p) x # to :: Rep (M1 i c f p) x -> M1 i c f p #
Generic ((f :.: g) p)	Since: base-4.7.0.0
Instance details Defined in GHC.Generics Associated Types type Rep ((f :.: g) p) :: Type -> Type # Methods from :: (f :.: g) p -> Rep ((f :.: g) p) x # to :: Rep ((f :.: g) p) x -> (f :.: g) p #
Generic (a, b, c, d, e)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (a, b, c, d, e) :: Type -> Type # Methods from :: (a, b, c, d, e) -> Rep (a, b, c, d, e) x # to :: Rep (a, b, c, d, e) x -> (a, b, c, d, e) #
Generic (Compose f g a)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Associated Types type Rep (Compose f g a) :: Type -> Type # Methods from :: Compose f g a -> Rep (Compose f g a) x # to :: Rep (Compose f g a) x -> Compose f g a #
Generic (a, b, c, d, e, f)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (a, b, c, d, e, f) :: Type -> Type # Methods from :: (a, b, c, d, e, f) -> Rep (a, b, c, d, e, f) x # to :: Rep (a, b, c, d, e, f) x -> (a, b, c, d, e, f) #
Generic (a, b, c, d, e, f, g)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (a, b, c, d, e, f, g) :: Type -> Type # Methods from :: (a, b, c, d, e, f, g) -> Rep (a, b, c, d, e, f, g) x # to :: Rep (a, b, c, d, e, f, g) x -> (a, b, c, d, e, f, g) #

class Generic1 (f :: k -> Type) #

Representable types of kind * -> * (or kind k -> *, when PolyKinds is enabled). This class is derivable in GHC with the DeriveGeneric flag on.

A Generic1 instance must satisfy the following laws:

from1 . to1 ≡ id
to1 . from1 ≡ id

Minimal complete definition

from1, to1

Instances

Instances details

Generic1 (V1 :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 V1 :: k -> Type # Methods from1 :: forall (a :: k0). V1 a -> Rep1 V1 a # to1 :: forall (a :: k0). Rep1 V1 a -> V1 a #
Generic1 (U1 :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 U1 :: k -> Type # Methods from1 :: forall (a :: k0). U1 a -> Rep1 U1 a # to1 :: forall (a :: k0). Rep1 U1 a -> U1 a #
Generic1 (Proxy :: k -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 Proxy :: k -> Type # Methods from1 :: forall (a :: k0). Proxy a -> Rep1 Proxy a # to1 :: forall (a :: k0). Rep1 Proxy a -> Proxy a #
Generic1 (Const a :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Associated Types type Rep1 (Const a) :: k -> Type # Methods from1 :: forall (a0 :: k0). Const a a0 -> Rep1 (Const a) a0 # to1 :: forall (a0 :: k0). Rep1 (Const a) a0 -> Const a a0 #
Generic1 (Alt f :: k -> Type)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep1 (Alt f) :: k -> Type # Methods from1 :: forall (a :: k0). Alt f a -> Rep1 (Alt f) a # to1 :: forall (a :: k0). Rep1 (Alt f) a -> Alt f a #
Generic1 (URec (Ptr ()) :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec (Ptr ())) :: k -> Type # Methods from1 :: forall (a :: k0). URec (Ptr ()) a -> Rep1 (URec (Ptr ())) a # to1 :: forall (a :: k0). Rep1 (URec (Ptr ())) a -> URec (Ptr ()) a #
Generic1 (URec Char :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Char) :: k -> Type # Methods from1 :: forall (a :: k0). URec Char a -> Rep1 (URec Char) a # to1 :: forall (a :: k0). Rep1 (URec Char) a -> URec Char a #
Generic1 (URec Double :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Double) :: k -> Type # Methods from1 :: forall (a :: k0). URec Double a -> Rep1 (URec Double) a # to1 :: forall (a :: k0). Rep1 (URec Double) a -> URec Double a #
Generic1 (URec Float :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Float) :: k -> Type # Methods from1 :: forall (a :: k0). URec Float a -> Rep1 (URec Float) a # to1 :: forall (a :: k0). Rep1 (URec Float) a -> URec Float a #
Generic1 (URec Int :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Int) :: k -> Type # Methods from1 :: forall (a :: k0). URec Int a -> Rep1 (URec Int) a # to1 :: forall (a :: k0). Rep1 (URec Int) a -> URec Int a #
Generic1 (URec Word :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (URec Word) :: k -> Type # Methods from1 :: forall (a :: k0). URec Word a -> Rep1 (URec Word) a # to1 :: forall (a :: k0). Rep1 (URec Word) a -> URec Word a #
Generic1 (Rec1 f :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (Rec1 f) :: k -> Type # Methods from1 :: forall (a :: k0). Rec1 f a -> Rep1 (Rec1 f) a # to1 :: forall (a :: k0). Rep1 (Rec1 f) a -> Rec1 f a #
Generic1 (Ap f :: k -> Type)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Associated Types type Rep1 (Ap f) :: k -> Type # Methods from1 :: forall (a :: k0). Ap f a -> Rep1 (Ap f) a # to1 :: forall (a :: k0). Rep1 (Ap f) a -> Ap f a #
Generic1 (Sum f g :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Associated Types type Rep1 (Sum f g) :: k -> Type # Methods from1 :: forall (a :: k0). Sum f g a -> Rep1 (Sum f g) a # to1 :: forall (a :: k0). Rep1 (Sum f g) a -> Sum f g a #
Generic1 (Product f g :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Associated Types type Rep1 (Product f g) :: k -> Type # Methods from1 :: forall (a :: k0). Product f g a -> Rep1 (Product f g) a # to1 :: forall (a :: k0). Rep1 (Product f g) a -> Product f g a #
Generic1 (K1 i c :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (K1 i c) :: k -> Type # Methods from1 :: forall (a :: k0). K1 i c a -> Rep1 (K1 i c) a # to1 :: forall (a :: k0). Rep1 (K1 i c) a -> K1 i c a #
Generic1 (f :+: g :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (f :+: g) :: k -> Type # Methods from1 :: forall (a :: k0). (f :+: g) a -> Rep1 (f :+: g) a # to1 :: forall (a :: k0). Rep1 (f :+: g) a -> (f :+: g) a #
Generic1 (f :*: g :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (f :: g) :: k -> Type # Methods from1 :: forall (a :: k0). (f :: g) a -> Rep1 (f :: g) a # to1 :: forall (a :: k0). Rep1 (f :: g) a -> (f :*: g) a #
Functor f => Generic1 (Compose f g :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Associated Types type Rep1 (Compose f g) :: k -> Type # Methods from1 :: forall (a :: k0). Compose f g a -> Rep1 (Compose f g) a # to1 :: forall (a :: k0). Rep1 (Compose f g) a -> Compose f g a #
Generic1 (M1 i c f :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (M1 i c f) :: k -> Type # Methods from1 :: forall (a :: k0). M1 i c f a -> Rep1 (M1 i c f) a # to1 :: forall (a :: k0). Rep1 (M1 i c f) a -> M1 i c f a #
Functor f => Generic1 (f :.: g :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (f :.: g) :: k -> Type # Methods from1 :: forall (a :: k0). (f :.: g) a -> Rep1 (f :.: g) a # to1 :: forall (a :: k0). Rep1 (f :.: g) a -> (f :.: g) a #
Generic1 []	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 [] :: k -> Type # Methods from1 :: forall (a :: k). [a] -> Rep1 [] a # to1 :: forall (a :: k). Rep1 [] a -> [a] #
Generic1 Maybe	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 Maybe :: k -> Type # Methods from1 :: forall (a :: k). Maybe a -> Rep1 Maybe a # to1 :: forall (a :: k). Rep1 Maybe a -> Maybe a #
Generic1 Par1	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 Par1 :: k -> Type # Methods from1 :: forall (a :: k). Par1 a -> Rep1 Par1 a # to1 :: forall (a :: k). Rep1 Par1 a -> Par1 a #
Generic1 Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 Min :: k -> Type # Methods from1 :: forall (a :: k). Min a -> Rep1 Min a # to1 :: forall (a :: k). Rep1 Min a -> Min a #
Generic1 Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 Max :: k -> Type # Methods from1 :: forall (a :: k). Max a -> Rep1 Max a # to1 :: forall (a :: k). Rep1 Max a -> Max a #
Generic1 First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 First :: k -> Type # Methods from1 :: forall (a :: k). First a -> Rep1 First a # to1 :: forall (a :: k). Rep1 First a -> First a #
Generic1 Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 Last :: k -> Type # Methods from1 :: forall (a :: k). Last a -> Rep1 Last a # to1 :: forall (a :: k). Rep1 Last a -> Last a #
Generic1 WrappedMonoid	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 WrappedMonoid :: k -> Type # Methods from1 :: forall (a :: k). WrappedMonoid a -> Rep1 WrappedMonoid a # to1 :: forall (a :: k). Rep1 WrappedMonoid a -> WrappedMonoid a #
Generic1 Option	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 Option :: k -> Type # Methods from1 :: forall (a :: k). Option a -> Rep1 Option a # to1 :: forall (a :: k). Rep1 Option a -> Option a #
Generic1 ZipList	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep1 ZipList :: k -> Type # Methods from1 :: forall (a :: k). ZipList a -> Rep1 ZipList a # to1 :: forall (a :: k). Rep1 ZipList a -> ZipList a #
Generic1 Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Associated Types type Rep1 Identity :: k -> Type # Methods from1 :: forall (a :: k). Identity a -> Rep1 Identity a # to1 :: forall (a :: k). Rep1 Identity a -> Identity a #
Generic1 First	Since: base-4.7.0.0
Instance details Defined in Data.Monoid Associated Types type Rep1 First :: k -> Type # Methods from1 :: forall (a :: k). First a -> Rep1 First a # to1 :: forall (a :: k). Rep1 First a -> First a #
Generic1 Last	Since: base-4.7.0.0
Instance details Defined in Data.Monoid Associated Types type Rep1 Last :: k -> Type # Methods from1 :: forall (a :: k). Last a -> Rep1 Last a # to1 :: forall (a :: k). Rep1 Last a -> Last a #
Generic1 Dual	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep1 Dual :: k -> Type # Methods from1 :: forall (a :: k). Dual a -> Rep1 Dual a # to1 :: forall (a :: k). Rep1 Dual a -> Dual a #
Generic1 Sum	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep1 Sum :: k -> Type # Methods from1 :: forall (a :: k). Sum a -> Rep1 Sum a # to1 :: forall (a :: k). Rep1 Sum a -> Sum a #
Generic1 Product	Since: base-4.7.0.0
Instance details Defined in Data.Semigroup.Internal Associated Types type Rep1 Product :: k -> Type # Methods from1 :: forall (a :: k). Product a -> Rep1 Product a # to1 :: forall (a :: k). Rep1 Product a -> Product a #
Generic1 Down	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 Down :: k -> Type # Methods from1 :: forall (a :: k). Down a -> Rep1 Down a # to1 :: forall (a :: k). Rep1 Down a -> Down a #
Generic1 NonEmpty	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 NonEmpty :: k -> Type # Methods from1 :: forall (a :: k). NonEmpty a -> Rep1 NonEmpty a # to1 :: forall (a :: k). Rep1 NonEmpty a -> NonEmpty a #
Generic1 (Either a :: Type -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 (Either a) :: k -> Type # Methods from1 :: forall (a0 :: k). Either a a0 -> Rep1 (Either a) a0 # to1 :: forall (a0 :: k). Rep1 (Either a) a0 -> Either a a0 #
Generic1 ((,) a :: Type -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 ((,) a) :: k -> Type # Methods from1 :: forall (a0 :: k). (a, a0) -> Rep1 ((,) a) a0 # to1 :: forall (a0 :: k). Rep1 ((,) a) a0 -> (a, a0) #
Generic1 (Arg a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Associated Types type Rep1 (Arg a) :: k -> Type # Methods from1 :: forall (a0 :: k). Arg a a0 -> Rep1 (Arg a) a0 # to1 :: forall (a0 :: k). Rep1 (Arg a) a0 -> Arg a a0 #
Generic1 (WrappedMonad m :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep1 (WrappedMonad m) :: k -> Type # Methods from1 :: forall (a :: k). WrappedMonad m a -> Rep1 (WrappedMonad m) a # to1 :: forall (a :: k). Rep1 (WrappedMonad m) a -> WrappedMonad m a #
Generic1 ((,,) a b :: Type -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 ((,,) a b) :: k -> Type # Methods from1 :: forall (a0 :: k). (a, b, a0) -> Rep1 ((,,) a b) a0 # to1 :: forall (a0 :: k). Rep1 ((,,) a b) a0 -> (a, b, a0) #
Generic1 (WrappedArrow a b :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep1 (WrappedArrow a b) :: k -> Type # Methods from1 :: forall (a0 :: k). WrappedArrow a b a0 -> Rep1 (WrappedArrow a b) a0 # to1 :: forall (a0 :: k). Rep1 (WrappedArrow a b) a0 -> WrappedArrow a b a0 #
Generic1 (Kleisli m a :: Type -> Type)	Since: base-4.14.0.0
Instance details Defined in Control.Arrow Associated Types type Rep1 (Kleisli m a) :: k -> Type # Methods from1 :: forall (a0 :: k). Kleisli m a a0 -> Rep1 (Kleisli m a) a0 # to1 :: forall (a0 :: k). Rep1 (Kleisli m a) a0 -> Kleisli m a a0 #
Generic1 ((,,,) a b c :: Type -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 ((,,,) a b c) :: k -> Type # Methods from1 :: forall (a0 :: k). (a, b, c, a0) -> Rep1 ((,,,) a b c) a0 # to1 :: forall (a0 :: k). Rep1 ((,,,) a b c) a0 -> (a, b, c, a0) #
Generic1 ((,,,,) a b c d :: Type -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 ((,,,,) a b c d) :: k -> Type # Methods from1 :: forall (a0 :: k). (a, b, c, d, a0) -> Rep1 ((,,,,) a b c d) a0 # to1 :: forall (a0 :: k). Rep1 ((,,,,) a b c d) a0 -> (a, b, c, d, a0) #
Generic1 ((,,,,,) a b c d e :: Type -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 ((,,,,,) a b c d e) :: k -> Type # Methods from1 :: forall (a0 :: k). (a, b, c, d, e, a0) -> Rep1 ((,,,,,) a b c d e) a0 # to1 :: forall (a0 :: k). Rep1 ((,,,,,) a b c d e) a0 -> (a, b, c, d, e, a0) #
Generic1 ((,,,,,,) a b c d e f :: Type -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 ((,,,,,,) a b c d e f) :: k -> Type # Methods from1 :: forall (a0 :: k). (a, b, c, d, e, f, a0) -> Rep1 ((,,,,,,) a b c d e f) a0 # to1 :: forall (a0 :: k). Rep1 ((,,,,,,) a b c d e f) a0 -> (a, b, c, d, e, f, a0) #

class Typeable (a :: k) #

The class Typeable allows a concrete representation of a type to be calculated.

Minimal complete definition

typeRep#

fromIntegral :: (Integral a, Num b) => a -> b #

general coercion from integral types

Type level

type Type = Type #

The kind of types with lifted values. For example Int :: Type.

data Proxy (t :: k) #

Proxy is a type that holds no data, but has a phantom parameter of arbitrary type (or even kind). Its use is to provide type information, even though there is no value available of that type (or it may be too costly to create one).

Historically, Proxy :: Proxy a is a safer alternative to the undefined :: a idiom.

>>> Proxy :: Proxy (Void, Int -> Int)
Proxy

Proxy can even hold types of higher kinds,

>>> Proxy :: Proxy Either
Proxy

>>> Proxy :: Proxy Functor
Proxy

>>> Proxy :: Proxy complicatedStructure
Proxy

Constructors

Proxy

Instances

Instances details

Generic1 (Proxy :: k -> Type)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep1 Proxy :: k -> Type # Methods from1 :: forall (a :: k0). Proxy a -> Rep1 Proxy a # to1 :: forall (a :: k0). Rep1 Proxy a -> Proxy a #
Monad (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods (>>=) :: Proxy a -> (a -> Proxy b) -> Proxy b # (>>) :: Proxy a -> Proxy b -> Proxy b # return :: a -> Proxy a #
Functor (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods fmap :: (a -> b) -> Proxy a -> Proxy b # (<$) :: a -> Proxy b -> Proxy a #
Applicative (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods pure :: a -> Proxy a # (<>) :: Proxy (a -> b) -> Proxy a -> Proxy b # liftA2 :: (a -> b -> c) -> Proxy a -> Proxy b -> Proxy c # (>) :: Proxy a -> Proxy b -> Proxy b # (<*) :: Proxy a -> Proxy b -> Proxy a #
Foldable (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> m # foldMap' :: Monoid m => (a -> m) -> Proxy a -> m # foldr :: (a -> b -> b) -> b -> Proxy a -> b # foldr' :: (a -> b -> b) -> b -> Proxy a -> b # foldl :: (b -> a -> b) -> b -> Proxy a -> b # foldl' :: (b -> a -> b) -> b -> Proxy a -> b # foldr1 :: (a -> a -> a) -> Proxy a -> a # foldl1 :: (a -> a -> a) -> Proxy a -> a # toList :: Proxy a -> [a] # null :: Proxy a -> Bool # length :: Proxy a -> Int # elem :: Eq a => a -> Proxy a -> Bool # maximum :: Ord a => Proxy a -> a # minimum :: Ord a => Proxy a -> a # sum :: Num a => Proxy a -> a # product :: Num a => Proxy a -> a #
Traversable (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Proxy a -> f (Proxy b) # sequenceA :: Applicative f => Proxy (f a) -> f (Proxy a) # mapM :: Monad m => (a -> m b) -> Proxy a -> m (Proxy b) # sequence :: Monad m => Proxy (m a) -> m (Proxy a) #
Contravariant (Proxy :: Type -> Type)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a -> b) -> Proxy b -> Proxy a # (>$) :: b -> Proxy b -> Proxy a #
Eq1 (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a -> b -> Bool) -> Proxy a -> Proxy b -> Bool #
Ord1 (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a -> b -> Ordering) -> Proxy a -> Proxy b -> Ordering #
Read1 (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Proxy a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Proxy a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Proxy a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Proxy a] #
Show1 (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Proxy a -> ShowS # liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Proxy a] -> ShowS #
Alternative (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Proxy Methods empty :: Proxy a # (<\|>) :: Proxy a -> Proxy a -> Proxy a # some :: Proxy a -> Proxy [a] # many :: Proxy a -> Proxy [a] #
MonadPlus (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Proxy Methods mzero :: Proxy a # mplus :: Proxy a -> Proxy a -> Proxy a #
Bounded (Proxy t)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods minBound :: Proxy t # maxBound :: Proxy t #
Enum (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods succ :: Proxy s -> Proxy s # pred :: Proxy s -> Proxy s # toEnum :: Int -> Proxy s # fromEnum :: Proxy s -> Int # enumFrom :: Proxy s -> [Proxy s] # enumFromThen :: Proxy s -> Proxy s -> [Proxy s] # enumFromTo :: Proxy s -> Proxy s -> [Proxy s] # enumFromThenTo :: Proxy s -> Proxy s -> Proxy s -> [Proxy s] #
Eq (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods (==) :: Proxy s -> Proxy s -> Bool # (/=) :: Proxy s -> Proxy s -> Bool #
Ord (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods compare :: Proxy s -> Proxy s -> Ordering # (<) :: Proxy s -> Proxy s -> Bool # (<=) :: Proxy s -> Proxy s -> Bool # (>) :: Proxy s -> Proxy s -> Bool # (>=) :: Proxy s -> Proxy s -> Bool # max :: Proxy s -> Proxy s -> Proxy s # min :: Proxy s -> Proxy s -> Proxy s #
Read (Proxy t)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods readsPrec :: Int -> ReadS (Proxy t) # readList :: ReadS [Proxy t] # readPrec :: ReadPrec (Proxy t) # readListPrec :: ReadPrec [Proxy t] #
Show (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods showsPrec :: Int -> Proxy s -> ShowS # show :: Proxy s -> String # showList :: [Proxy s] -> ShowS #
Ix (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods range :: (Proxy s, Proxy s) -> [Proxy s] # index :: (Proxy s, Proxy s) -> Proxy s -> Int # unsafeIndex :: (Proxy s, Proxy s) -> Proxy s -> Int # inRange :: (Proxy s, Proxy s) -> Proxy s -> Bool # rangeSize :: (Proxy s, Proxy s) -> Int # unsafeRangeSize :: (Proxy s, Proxy s) -> Int #
Generic (Proxy t)	Since: base-4.6.0.0
Instance details Defined in GHC.Generics Associated Types type Rep (Proxy t) :: Type -> Type # Methods from :: Proxy t -> Rep (Proxy t) x # to :: Rep (Proxy t) x -> Proxy t #
Semigroup (Proxy s)	Since: base-4.9.0.0
Instance details Defined in Data.Proxy Methods (<>) :: Proxy s -> Proxy s -> Proxy s # sconcat :: NonEmpty (Proxy s) -> Proxy s # stimes :: Integral b => b -> Proxy s -> Proxy s #
Monoid (Proxy s)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods mempty :: Proxy s # mappend :: Proxy s -> Proxy s -> Proxy s # mconcat :: [Proxy s] -> Proxy s #
type Rep1 (Proxy :: k -> Type)
Instance details Defined in GHC.Generics type Rep1 (Proxy :: k -> Type) = D1 ('MetaData "Proxy" "Data.Proxy" "base" 'False) (C1 ('MetaCons "Proxy" 'PrefixI 'False) (U1 :: k -> Type))
type Rep (Proxy t)
Instance details Defined in GHC.Generics type Rep (Proxy t) = D1 ('MetaData "Proxy" "Data.Proxy" "base" 'False) (C1 ('MetaCons "Proxy" 'PrefixI 'False) (U1 :: Type -> Type))

IO

data IO a #

A value of type IO a is a computation which, when performed, does some I/O before returning a value of type a.

There is really only one way to "perform" an I/O action: bind it to Main.main in your program. When your program is run, the I/O will be performed. It isn't possible to perform I/O from an arbitrary function, unless that function is itself in the IO monad and called at some point, directly or indirectly, from Main.main.

IO is a monad, so IO actions can be combined using either the do-notation or the >> and >>= operations from the Monad class.

Instances

Instances details

Monad IO	Since: base-2.1
Instance details Defined in GHC.Base Methods (>>=) :: IO a -> (a -> IO b) -> IO b # (>>) :: IO a -> IO b -> IO b # return :: a -> IO a #
Functor IO	Since: base-2.1
Instance details Defined in GHC.Base Methods fmap :: (a -> b) -> IO a -> IO b # (<$) :: a -> IO b -> IO a #
MonadFix IO	Since: base-2.1
Instance details Defined in Control.Monad.Fix Methods mfix :: (a -> IO a) -> IO a #
MonadFail IO	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fail Methods fail :: String -> IO a #
Applicative IO	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> IO a # (<>) :: IO (a -> b) -> IO a -> IO b # liftA2 :: (a -> b -> c) -> IO a -> IO b -> IO c # (>) :: IO a -> IO b -> IO b # (<*) :: IO a -> IO b -> IO a #
MonadIO IO	Since: base-4.9.0.0
Instance details Defined in Control.Monad.IO.Class Methods liftIO :: IO a -> IO a #
Alternative IO	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods empty :: IO a # (<\|>) :: IO a -> IO a -> IO a # some :: IO a -> IO [a] # many :: IO a -> IO [a] #
MonadPlus IO	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods mzero :: IO a # mplus :: IO a -> IO a -> IO a #
Semigroup a => Semigroup (IO a)	Since: base-4.10.0.0
Instance details Defined in GHC.Base Methods (<>) :: IO a -> IO a -> IO a # sconcat :: NonEmpty (IO a) -> IO a # stimes :: Integral b => b -> IO a -> IO a #
Monoid a => Monoid (IO a)	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods mempty :: IO a # mappend :: IO a -> IO a -> IO a # mconcat :: [IO a] -> IO a #

class Monad m => MonadIO (m :: Type -> Type) where #

Monads in which IO computations may be embedded. Any monad built by applying a sequence of monad transformers to the IO monad will be an instance of this class.

Instances should satisfy the following laws, which state that liftIO is a transformer of monads:

```
liftIO . return = return
```

liftIO (m >>= f) = liftIO m >>= (liftIO . f)

Methods

liftIO :: IO a -> m a #

Lift a computation from the IO monad.

Instances

Instances details

MonadIO IO	Since: base-4.9.0.0
Instance details Defined in Control.Monad.IO.Class Methods liftIO :: IO a -> IO a #
(Error e, MonadIO m) => MonadIO (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods liftIO :: IO a -> ErrorT e m a #

Console

print :: (MonadIO m, Show a) => a -> m () Source #

The print function outputs a value of any printable type to the standard output device. Printable types are those that are instances of class Show; print converts values to strings for output using the show operation and adds a newline.

For example, a program to print the first 20 integers and their powers of 2 could be written as:

main = print ([(n, 2^n) | n <- [0..19]])

Note: This function is lifted to the MonadIO class.

class Print a Source #

Minimal complete definition

hPutStr, hPutStrLn

Instances

Instances details

Print ByteString Source #
Instance details Defined in Verset Methods hPutStr :: MonadIO m => Handle -> ByteString -> m () Source # putStr :: MonadIO m => ByteString -> m () Source # hPutStrLn :: MonadIO m => Handle -> ByteString -> m () Source # putStrLn :: MonadIO m => ByteString -> m () Source # putErrLn :: MonadIO m => ByteString -> m () Source #
Print ByteString Source #
Instance details Defined in Verset Methods hPutStr :: MonadIO m => Handle -> ByteString -> m () Source # putStr :: MonadIO m => ByteString -> m () Source # hPutStrLn :: MonadIO m => Handle -> ByteString -> m () Source # putStrLn :: MonadIO m => ByteString -> m () Source # putErrLn :: MonadIO m => ByteString -> m () Source #
Print Text Source #
Instance details Defined in Verset Methods hPutStr :: MonadIO m => Handle -> Text -> m () Source # putStr :: MonadIO m => Text -> m () Source # hPutStrLn :: MonadIO m => Handle -> Text -> m () Source # putStrLn :: MonadIO m => Text -> m () Source # putErrLn :: MonadIO m => Text -> m () Source #
Print Text Source #
Instance details Defined in Verset Methods hPutStr :: MonadIO m => Handle -> Text -> m () Source # putStr :: MonadIO m => Text -> m () Source # hPutStrLn :: MonadIO m => Handle -> Text -> m () Source # putStrLn :: MonadIO m => Text -> m () Source # putErrLn :: MonadIO m => Text -> m () Source #
Print [Char] Source #
Instance details Defined in Verset Methods hPutStr :: MonadIO m => Handle -> [Char] -> m () Source # putStr :: MonadIO m => [Char] -> m () Source # hPutStrLn :: MonadIO m => Handle -> [Char] -> m () Source # putStrLn :: MonadIO m => [Char] -> m () Source # putErrLn :: MonadIO m => [Char] -> m () Source #

hPutStr :: (Print a, MonadIO m) => Handle -> a -> m () Source #

putStr :: (Print a, MonadIO m) => a -> m () Source #

hPutStrLn :: (Print a, MonadIO m) => Handle -> a -> m () Source #

putStrLn :: (Print a, MonadIO m) => a -> m () Source #

putErrLn :: (Print a, MonadIO m) => a -> m () Source #

putText :: MonadIO m => Text -> m () Source #

putErrText :: MonadIO m => Text -> m () Source #

putLText :: MonadIO m => Text -> m () Source #

putByteString :: MonadIO m => ByteString -> m () Source #

putLByteString :: MonadIO m => ByteString -> m () Source #

Error handling and debugging

type HasCallStack = ?callStack :: CallStack #

Request a CallStack.

NOTE: The implicit parameter ?callStack :: CallStack is an implementation detail and should not be considered part of the CallStack API, we may decide to change the implementation in the future.

Since: base-4.9.0.0

class Monad m => MonadFail (m :: Type -> Type) #

When a value is bound in do-notation, the pattern on the left hand side of <- might not match. In this case, this class provides a function to recover.

A Monad without a MonadFail instance may only be used in conjunction with pattern that always match, such as newtypes, tuples, data types with only a single data constructor, and irrefutable patterns (~pat).

Instances of MonadFail should satisfy the following law: fail s should be a left zero for >>=,

fail s >>= f  =  fail s

If your Monad is also MonadPlus, a popular definition is

fail _ = mzero

Since: base-4.9.0.0

Minimal complete definition

fail

Instances

Instances details

MonadFail []	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fail Methods fail :: String -> [a] #
MonadFail Maybe	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fail Methods fail :: String -> Maybe a #
MonadFail IO	Since: base-4.9.0.0
Instance details Defined in Control.Monad.Fail Methods fail :: String -> IO a #
MonadFail ReadP	Since: base-4.9.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods fail :: String -> ReadP a #
MonadFail P	Since: base-4.9.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods fail :: String -> P a #
MonadFail f => MonadFail (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods fail :: String -> Ap f a #
(Monad m, Error e) => MonadFail (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods fail :: String -> ErrorT e m a #

undefined :: HasCallStack => a Source #

Warning: undefined should be used only for debugging

Throw an undefined error. Use only for debugging.

trace :: Text -> a -> a Source #

Warning: trace should be used only for debugging

The trace function outputs the trace message given as its first argument, before returning the second argument as its result.

For example, this returns the value of f x but first outputs the message.

trace ("calling f with x = " ++ show x) (f x)

The trace function should only be used for debugging, or for monitoring execution. The function is not referentially transparent: its type indicates that it is a pure function but it has the side effect of outputting the trace message.

traceIO :: MonadIO m => Text -> m () Source #

Warning: traceIO should be used only for debugging

The traceIO function outputs the trace message from the IO monad. This sequences the output with respect to other IO actions.

traceId :: Text -> Text Source #

Warning: traceId should be used only for debugging

Like trace but returns the message instead of a third value.

traceM :: Applicative m => Text -> m () Source #

Warning: traceM should be used only for debugging

Like trace but returning unit in an arbitrary Applicative context. Allows for convenient use in do-notation.

Note that the application of traceM is not an action in the Applicative context, as traceIO is in the MonadIO type. While the fresh bindings in the following example will force the traceM expressions to be reduced every time the do-block is executed, traceM "not crashed" would only be reduced once, and the message would only be printed once. If your monad is in MonadIO, traceIO may be a better option.

... = do
  x <- ...
  traceM $ "x: " ++ show x
  y <- ...
  traceM $ "y: " ++ show y

traceShow :: Show a => a -> b -> b Source #

Warning: traceShow should be used only for debugging

Like trace, but uses show on the argument to convert it to a String.

This makes it convenient for printing the values of interesting variables or expressions inside a function. For example here we print the value of the variables x and z:

f x y =
    traceShow (x, z) $ result
  where
    z = ...
    ...

traceShowId :: Show a => a -> a Source #

Warning: traceShowId should be used only for debugging

Like traceShow but returns the shown value instead of a third value.

traceShowM :: (Show a, Applicative m) => a -> m () Source #

Warning: traceShowM should be used only for debugging

Like traceM, but uses show on the argument to convert it to a String.

... = do
  x <- ...
  traceShowM $ x
  y <- ...
  traceShowM $ x + y

Time

data UTCTime #

This is the simplest representation of UTC. It consists of the day number, and a time offset from midnight. Note that if a day has a leap second added to it, it will have 86401 seconds.

Instances

Instances details

Eq UTCTime
Instance details Defined in Data.Time.Clock.Internal.UTCTime Methods (==) :: UTCTime -> UTCTime -> Bool # (/=) :: UTCTime -> UTCTime -> Bool #
Data UTCTime
Instance details Defined in Data.Time.Clock.Internal.UTCTime Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> UTCTime -> c UTCTime # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c UTCTime # toConstr :: UTCTime -> Constr # dataTypeOf :: UTCTime -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c UTCTime) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c UTCTime) # gmapT :: (forall b. Data b => b -> b) -> UTCTime -> UTCTime # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> UTCTime -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> UTCTime -> r # gmapQ :: (forall d. Data d => d -> u) -> UTCTime -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> UTCTime -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> UTCTime -> m UTCTime # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> UTCTime -> m UTCTime # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> UTCTime -> m UTCTime #
Ord UTCTime
Instance details Defined in Data.Time.Clock.Internal.UTCTime Methods compare :: UTCTime -> UTCTime -> Ordering # (<) :: UTCTime -> UTCTime -> Bool # (<=) :: UTCTime -> UTCTime -> Bool # (>) :: UTCTime -> UTCTime -> Bool # (>=) :: UTCTime -> UTCTime -> Bool # max :: UTCTime -> UTCTime -> UTCTime # min :: UTCTime -> UTCTime -> UTCTime #
NFData UTCTime
Instance details Defined in Data.Time.Clock.Internal.UTCTime Methods rnf :: UTCTime -> () #

data LocalTime #

A simple day and time aggregate, where the day is of the specified parameter, and the time is a TimeOfDay. Conversion of this (as local civil time) to UTC depends on the time zone. Conversion of this (as local mean time) to UT1 depends on the longitude.

Instances

Instances details

Eq LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods (==) :: LocalTime -> LocalTime -> Bool # (/=) :: LocalTime -> LocalTime -> Bool #
Data LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> LocalTime -> c LocalTime # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c LocalTime # toConstr :: LocalTime -> Constr # dataTypeOf :: LocalTime -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c LocalTime) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c LocalTime) # gmapT :: (forall b. Data b => b -> b) -> LocalTime -> LocalTime # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> LocalTime -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> LocalTime -> r # gmapQ :: (forall d. Data d => d -> u) -> LocalTime -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> LocalTime -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> LocalTime -> m LocalTime # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> LocalTime -> m LocalTime # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> LocalTime -> m LocalTime #
Ord LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods compare :: LocalTime -> LocalTime -> Ordering # (<) :: LocalTime -> LocalTime -> Bool # (<=) :: LocalTime -> LocalTime -> Bool # (>) :: LocalTime -> LocalTime -> Bool # (>=) :: LocalTime -> LocalTime -> Bool # max :: LocalTime -> LocalTime -> LocalTime # min :: LocalTime -> LocalTime -> LocalTime #
Show LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods showsPrec :: Int -> LocalTime -> ShowS # show :: LocalTime -> String # showList :: [LocalTime] -> ShowS #
NFData LocalTime
Instance details Defined in Data.Time.LocalTime.Internal.LocalTime Methods rnf :: LocalTime -> () #

data NominalDiffTime #

This is a length of time, as measured by UTC. It has a precision of 10^-12 s.

Conversion functions will treat it as seconds. For example, (0.010 :: NominalDiffTime) corresponds to 10 milliseconds.

It ignores leap-seconds, so it's not necessarily a fixed amount of clock time. For instance, 23:00 UTC + 2 hours of NominalDiffTime = 01:00 UTC (+ 1 day), regardless of whether a leap-second intervened.

Instances

Instances details

Enum NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods succ :: NominalDiffTime -> NominalDiffTime # pred :: NominalDiffTime -> NominalDiffTime # toEnum :: Int -> NominalDiffTime # fromEnum :: NominalDiffTime -> Int # enumFrom :: NominalDiffTime -> [NominalDiffTime] # enumFromThen :: NominalDiffTime -> NominalDiffTime -> [NominalDiffTime] # enumFromTo :: NominalDiffTime -> NominalDiffTime -> [NominalDiffTime] # enumFromThenTo :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime -> [NominalDiffTime] #
Eq NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (==) :: NominalDiffTime -> NominalDiffTime -> Bool # (/=) :: NominalDiffTime -> NominalDiffTime -> Bool #
Fractional NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (/) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # recip :: NominalDiffTime -> NominalDiffTime # fromRational :: Rational -> NominalDiffTime #
Data NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> NominalDiffTime -> c NominalDiffTime # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c NominalDiffTime # toConstr :: NominalDiffTime -> Constr # dataTypeOf :: NominalDiffTime -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c NominalDiffTime) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c NominalDiffTime) # gmapT :: (forall b. Data b => b -> b) -> NominalDiffTime -> NominalDiffTime # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> NominalDiffTime -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> NominalDiffTime -> r # gmapQ :: (forall d. Data d => d -> u) -> NominalDiffTime -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> NominalDiffTime -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> NominalDiffTime -> m NominalDiffTime # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> NominalDiffTime -> m NominalDiffTime # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> NominalDiffTime -> m NominalDiffTime #
Num NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (+) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # (-) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # (*) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # negate :: NominalDiffTime -> NominalDiffTime # abs :: NominalDiffTime -> NominalDiffTime # signum :: NominalDiffTime -> NominalDiffTime # fromInteger :: Integer -> NominalDiffTime #
Ord NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods compare :: NominalDiffTime -> NominalDiffTime -> Ordering # (<) :: NominalDiffTime -> NominalDiffTime -> Bool # (<=) :: NominalDiffTime -> NominalDiffTime -> Bool # (>) :: NominalDiffTime -> NominalDiffTime -> Bool # (>=) :: NominalDiffTime -> NominalDiffTime -> Bool # max :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # min :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime #
Real NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods toRational :: NominalDiffTime -> Rational #
RealFrac NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods properFraction :: Integral b => NominalDiffTime -> (b, NominalDiffTime) # truncate :: Integral b => NominalDiffTime -> b # round :: Integral b => NominalDiffTime -> b # ceiling :: Integral b => NominalDiffTime -> b # floor :: Integral b => NominalDiffTime -> b #
Show NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods showsPrec :: Int -> NominalDiffTime -> ShowS # show :: NominalDiffTime -> String # showList :: [NominalDiffTime] -> ShowS #
NFData NominalDiffTime
Instance details Defined in Data.Time.Clock.Internal.NominalDiffTime Methods rnf :: NominalDiffTime -> () #

Custom

data UUID #

Instances

Instances details

Eq UUID
Instance details Defined in Data.UUID.Types.Internal Methods (==) :: UUID -> UUID -> Bool # (/=) :: UUID -> UUID -> Bool #
Data UUID
Instance details Defined in Data.UUID.Types.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> UUID -> c UUID # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c UUID # toConstr :: UUID -> Constr # dataTypeOf :: UUID -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c UUID) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c UUID) # gmapT :: (forall b. Data b => b -> b) -> UUID -> UUID # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> UUID -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> UUID -> r # gmapQ :: (forall d. Data d => d -> u) -> UUID -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> UUID -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> UUID -> m UUID # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> UUID -> m UUID # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> UUID -> m UUID #
Ord UUID
Instance details Defined in Data.UUID.Types.Internal Methods compare :: UUID -> UUID -> Ordering # (<) :: UUID -> UUID -> Bool # (<=) :: UUID -> UUID -> Bool # (>) :: UUID -> UUID -> Bool # (>=) :: UUID -> UUID -> Bool # max :: UUID -> UUID -> UUID # min :: UUID -> UUID -> UUID #
Read UUID
Instance details Defined in Data.UUID.Types.Internal Methods readsPrec :: Int -> ReadS UUID # readList :: ReadS [UUID] # readPrec :: ReadPrec UUID # readListPrec :: ReadPrec [UUID] #
Show UUID
Instance details Defined in Data.UUID.Types.Internal Methods showsPrec :: Int -> UUID -> ShowS # show :: UUID -> String # showList :: [UUID] -> ShowS #
Storable UUID
Instance details Defined in Data.UUID.Types.Internal Methods sizeOf :: UUID -> Int # alignment :: UUID -> Int # peekElemOff :: Ptr UUID -> Int -> IO UUID # pokeElemOff :: Ptr UUID -> Int -> UUID -> IO () # peekByteOff :: Ptr b -> Int -> IO UUID # pokeByteOff :: Ptr b -> Int -> UUID -> IO () # peek :: Ptr UUID -> IO UUID # poke :: Ptr UUID -> UUID -> IO () #
Binary UUID
Instance details Defined in Data.UUID.Types.Internal Methods put :: UUID -> Put # get :: Get UUID # putList :: [UUID] -> Put #
NFData UUID
Instance details Defined in Data.UUID.Types.Internal Methods rnf :: UUID -> () #
Hashable UUID
Instance details Defined in Data.UUID.Types.Internal Methods hashWithSalt :: Int -> UUID -> Int hash :: UUID -> Int
Random UUID
Instance details Defined in Data.UUID.Types.Internal Methods randomR :: RandomGen g => (UUID, UUID) -> g -> (UUID, g) random :: RandomGen g => g -> (UUID, g) randomRs :: RandomGen g => (UUID, UUID) -> g -> [UUID] randoms :: RandomGen g => g -> [UUID]
Uniform UUID
Instance details Defined in Data.UUID.Types.Internal Methods uniformM :: StatefulGen g m => g -> m UUID
Lift UUID
Instance details Defined in Data.UUID.Types.Internal Methods lift :: UUID -> Q Exp # liftTyped :: UUID -> Q (TExp UUID) #

data ByteString #

A space-efficient representation of a Word8 vector, supporting many efficient operations.

A ByteString contains 8-bit bytes, or by using the operations from Data.ByteString.Char8 it can be interpreted as containing 8-bit characters.

Instances

Instances details

IsList ByteString	Since: bytestring-0.10.12.0
Instance details Defined in Data.ByteString.Internal Associated Types type Item ByteString # Methods fromList :: [Item ByteString] -> ByteString # fromListN :: Int -> [Item ByteString] -> ByteString # toList :: ByteString -> [Item ByteString] #
Eq ByteString
Instance details Defined in Data.ByteString.Internal Methods (==) :: ByteString -> ByteString -> Bool # (/=) :: ByteString -> ByteString -> Bool #
Data ByteString
Instance details Defined in Data.ByteString.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ByteString -> c ByteString # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ByteString # toConstr :: ByteString -> Constr # dataTypeOf :: ByteString -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c ByteString) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ByteString) # gmapT :: (forall b. Data b => b -> b) -> ByteString -> ByteString # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ByteString -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ByteString -> r # gmapQ :: (forall d. Data d => d -> u) -> ByteString -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> ByteString -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> ByteString -> m ByteString # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ByteString -> m ByteString # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ByteString -> m ByteString #
Ord ByteString
Instance details Defined in Data.ByteString.Internal Methods compare :: ByteString -> ByteString -> Ordering # (<) :: ByteString -> ByteString -> Bool # (<=) :: ByteString -> ByteString -> Bool # (>) :: ByteString -> ByteString -> Bool # (>=) :: ByteString -> ByteString -> Bool # max :: ByteString -> ByteString -> ByteString # min :: ByteString -> ByteString -> ByteString #
Read ByteString
Instance details Defined in Data.ByteString.Internal Methods readsPrec :: Int -> ReadS ByteString # readList :: ReadS [ByteString] # readPrec :: ReadPrec ByteString # readListPrec :: ReadPrec [ByteString] #
Show ByteString
Instance details Defined in Data.ByteString.Internal Methods showsPrec :: Int -> ByteString -> ShowS # show :: ByteString -> String # showList :: [ByteString] -> ShowS #
IsString ByteString	Beware: `fromString` truncates multi-byte characters to octets. e.g. "枯朶に烏のとまりけり秋の暮" becomes �6k�nh~�Q��n�
Instance details Defined in Data.ByteString.Internal Methods fromString :: String -> ByteString #
Semigroup ByteString
Instance details Defined in Data.ByteString.Internal Methods (<>) :: ByteString -> ByteString -> ByteString # sconcat :: NonEmpty ByteString -> ByteString # stimes :: Integral b => b -> ByteString -> ByteString #
Monoid ByteString
Instance details Defined in Data.ByteString.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString #
NFData ByteString
Instance details Defined in Data.ByteString.Internal Methods rnf :: ByteString -> () #
Print ByteString Source #
Instance details Defined in Verset Methods hPutStr :: MonadIO m => Handle -> ByteString -> m () Source # putStr :: MonadIO m => ByteString -> m () Source # hPutStrLn :: MonadIO m => Handle -> ByteString -> m () Source # putStrLn :: MonadIO m => ByteString -> m () Source # putErrLn :: MonadIO m => ByteString -> m () Source #
StringConv String ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> String -> ByteString Source #
StringConv ByteString ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString0 -> ByteString Source #
StringConv ByteString String Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString -> String Source #
StringConv ByteString ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString -> ByteString0 Source #
StringConv ByteString ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString -> ByteString Source #
StringConv ByteString Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString -> Text Source #
StringConv ByteString Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString -> Text Source #
StringConv Text ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text -> ByteString Source #
StringConv Text ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text -> ByteString Source #
type Item ByteString
Instance details Defined in Data.ByteString.Internal type Item ByteString = Word8

data Text #

A space efficient, packed, unboxed Unicode text type.

Instances

Instances details

Print Text Source #
Instance details Defined in Verset Methods hPutStr :: MonadIO m => Handle -> Text -> m () Source # putStr :: MonadIO m => Text -> m () Source # hPutStrLn :: MonadIO m => Handle -> Text -> m () Source # putStrLn :: MonadIO m => Text -> m () Source # putErrLn :: MonadIO m => Text -> m () Source #
StringConv String Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> String -> Text Source #
StringConv ByteString Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString -> Text Source #
StringConv ByteString Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> ByteString -> Text Source #
StringConv Text Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text0 -> Text Source #
StringConv Text String Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text -> String Source #
StringConv Text ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text -> ByteString Source #
StringConv Text ByteString Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text -> ByteString Source #
StringConv Text Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text -> Text0 Source #
StringConv Text Text Source #
Instance details Defined in Verset.Conv Methods strConv :: Leniency -> Text -> Text Source #
type Item Text
Instance details Defined in Data.Text type Item Text = Char

type FilePath = String #

File and directory names are values of type String, whose precise meaning is operating system dependent. Files can be opened, yielding a handle which can then be used to operate on the contents of that file.

(<<$>>) :: (Functor f, Functor g) => (a -> b) -> f (g a) -> f (g b) infixl 4 Source #

ordNub :: Ord a => [a] -> [a] Source #

identity :: a -> a Source #

The identity function, returns the give value unchanged.

Category (Coercion :: k -> k -> Type)	Since: base-4.7.0.0
Instance details Defined in Control.Category Methods id :: forall (a :: k0). Coercion a a # (.) :: forall (b :: k0) (c :: k0) (a :: k0). Coercion b c -> Coercion a b -> Coercion a c #
Category ((:~:) :: k -> k -> Type)	Since: base-4.7.0.0
Instance details Defined in Control.Category Methods id :: forall (a :: k0). a :~: a # (.) :: forall (b :: k0) (c :: k0) (a :: k0). (b :~: c) -> (a :~: b) -> a :~: c #
Category ((:~~:) :: k -> k -> Type)	Since: base-4.10.0.0
Instance details Defined in Control.Category Methods id :: forall (a :: k0). a :~~: a # (.) :: forall (b :: k0) (c :: k0) (a :: k0). (b :~~: c) -> (a :~~: b) -> a :~~: c #
Category Op
Instance details Defined in Data.Functor.Contravariant Methods id :: forall (a :: k). Op a a # (.) :: forall (b :: k) (c :: k) (a :: k). Op b c -> Op a b -> Op a c #
Monad m => Category (Kleisli m :: Type -> Type -> Type)	Since: base-3.0
Instance details Defined in Control.Arrow Methods id :: forall (a :: k). Kleisli m a a # (.) :: forall (b :: k) (c :: k) (a :: k). Kleisli m b c -> Kleisli m a b -> Kleisli m a c #
Category ((->) :: Type -> Type -> Type)	Since: base-3.0
Instance details Defined in Control.Category Methods id :: forall (a :: k). a -> a # (.) :: forall (b :: k) (c :: k) (a :: k). (b -> c) -> (a -> b) -> a -> c #
(Applicative f, Monad f) => Category (WhenMissing f k :: Type -> Type -> Type)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods id :: forall (a :: k0). WhenMissing f k a a # (.) :: forall (b :: k0) (c :: k0) (a :: k0). WhenMissing f k b c -> WhenMissing f k a b -> WhenMissing f k a c #
(Monad f, Applicative f) => Category (WhenMatched f k x :: Type -> Type -> Type)	Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods id :: forall (a :: k0). WhenMatched f k x a a # (.) :: forall (b :: k0) (c :: k0) (a :: k0). WhenMatched f k x b c -> WhenMatched f k x a b -> WhenMatched f k x a c #