Prelude

Documentation

(|>) :: a -> (a -> b) -> b infixr 1

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

asPath :: Text -> FilePath

asString :: Text -> String

asText :: String -> Text

cartProduct :: [a] -> [b] -> [(a, b)]

concat :: (Foldable t, MonadPlus m) => t (m a) -> m a

curry3 :: ((a, b, c) -> x) -> a -> b -> c -> x

curry4 :: ((a, b, c, d) -> x) -> a -> b -> c -> d -> x

error :: Text -> a

frt4 :: (a, b, c, d) -> d

fst3 :: (a, b, c) -> a

fst4 :: (a, b, c, d) -> a

groupOn :: Ord criterion => (item -> criterion) -> [item] -> [[item]]

listDirsRecursively :: FilePath -> IO [FilePath]

map :: Functor f => (a -> b) -> f a -> f b

mapAllFour :: (a -> x) -> (b -> y) -> (c -> z) -> (d -> l) -> (a, b, c, d) -> (x, y, z, l)

mapAllThree :: (a -> x) -> (b -> y) -> (c -> z) -> (a, b, c) -> (x, y, z)

mapBoth :: (a -> x) -> (b -> y) -> (a, b) -> (x, y)

mapFrt4 :: (d -> x) -> (a, b, c, d) -> (a, b, c, x)

mapFrtF4 :: Functor f => (d -> f x) -> (a, b, c, d) -> f (a, b, c, x)

mapFst :: (a -> x) -> (a, b) -> (x, b)

mapFst3 :: (a -> x) -> (a, b, c) -> (x, b, c)

mapFst4 :: (a -> x) -> (a, b, c, d) -> (x, b, c, d)

mapFstF :: Functor f => (a -> f x) -> (a, b) -> f (x, b)

mapFstF3 :: Functor f => (a -> f x) -> (a, b, c) -> f (x, b, c)

mapFstF4 :: Functor f => (a -> f x) -> (a, b, c, d) -> f (x, b, c, d)

mapSnd :: (b -> x) -> (a, b) -> (a, x)

mapSnd3 :: (b -> x) -> (a, b, c) -> (a, x, c)

mapSnd4 :: (b -> x) -> (a, b, c, d) -> (a, x, c, d)

mapSndF :: Functor f => (b -> f x) -> (a, b) -> f (a, x)

mapSndF3 :: Functor f => (b -> f x) -> (a, b, c) -> f (a, x, c)

mapSndF4 :: Functor f => (b -> f x) -> (a, b, c, d) -> f (a, x, c, d)

mapThd3 :: (c -> x) -> (a, b, c) -> (a, b, x)

mapThd4 :: (c -> x) -> (a, b, c, d) -> (a, b, x, d)

mapThdF3 :: Functor f => (c -> f x) -> (a, b, c) -> f (a, b, x)

mapThdF4 :: Functor f => (c -> f x) -> (a, b, c, d) -> f (a, b, x, d)

pam :: Functor f => f a -> (a -> b) -> f b

putStrFlush :: Text -> IO ()

regexMatch :: Text -> Text -> Maybe [Text]

return' :: Monad m => a -> m a

scalaGroupBy :: Ord criterion => (item -> criterion) -> [item] -> [(criterion, [item])]

showText :: Show a => a -> Text

snd3 :: (a, b, c) -> b

snd4 :: (a, b, c, d) -> b

thd3 :: (a, b, c) -> c

thd4 :: (a, b, c, d) -> c

tuple2To3a :: (a, b) -> x -> (x, a, b)

tuple2To3b :: (a, b) -> x -> (a, x, b)

tuple2To3c :: (a, b) -> x -> (a, b, x)

tuple3To4a :: (a, b, c) -> x -> (x, a, b, c)

tuple3To4b :: (a, b, c) -> x -> (a, x, b, c)

tuple3To4c :: (a, b, c) -> x -> (a, b, x, c)

tuple3To4d :: (a, b, c) -> x -> (a, b, c, x)

tuple4To5a :: (a, b, c, d) -> x -> (x, a, b, c, d)

tuple4To5b :: (a, b, c, d) -> x -> (a, x, b, c, d)

tuple4To5c :: (a, b, c, d) -> x -> (a, b, x, c, d)

tuple4To5d :: (a, b, c, d) -> x -> (a, b, c, x, d)

tuple4To5e :: (a, b, c, d) -> x -> (a, b, c, d, x)

uncurry3 :: (a -> b -> c -> x) -> (a, b, c) -> x

uncurry4 :: (a -> b -> c -> d -> x) -> (a, b, c, d) -> x

uncurry5 :: (a -> b -> c -> d -> e -> f) -> (a, b, c, d, e) -> f

unsafeRead :: Integral a => Text -> a

(***) :: Arrow a => a b c -> a b' c' -> a (b, b') (c, c') infixr 3

Split the input between the two argument arrows and combine their output. Note that this is in general not a functor.

The default definition may be overridden with a more efficient version if desired.

(&&&) :: Arrow a => a b c -> a b c' -> a b (c, c') infixr 3

Fanout: send the input to both argument arrows and combine their output.

The default definition may be overridden with a more efficient version if desired.

(>>>) :: Category cat => cat a b -> cat b c -> cat a c infixr 1

Left-to-right composition

class Functor f => Applicative (f :: * -> *) 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

• (<*>) = ap

• (*>) = (>>)

(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.

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

Sequence actions, discarding the value of the first argument.

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

Sequence actions, discarding the value of the second argument.

Instances

Applicative []

Since: base-2.1

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

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

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

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

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

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

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

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

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

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 First

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

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

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

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

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

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 NonEmpty

Since: base-4.9.0.0

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 (Either e)

Since: base-3.0

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 :: * -> *)

Since: base-4.9.0.0

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, Strings concatenate:

("hello ", (+15)) <*> ("world!", 2002)
("hello world!",2017)

Since: base-2.1

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

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

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 :: * -> *)

Since: base-4.7.0.0

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 (IParser t)

Defined in Data.Text.Internal.Read

Methods

pure :: a -> IParser t a

(<*>) :: IParser t (a -> b) -> IParser t a -> IParser t b

liftA2 :: (a -> b -> c) -> IParser t a -> IParser t b -> IParser t c

(*>) :: IParser t a -> IParser t b -> IParser t b

(<*) :: IParser t a -> IParser t b -> IParser t a

Applicative f => Applicative (Rec1 f)

Since: base-4.9.0.0

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

Arrow a => Applicative (WrappedArrow a b)

Since: base-2.1

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 f => Applicative (Alt f)

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)

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 ((->) a :: * -> *)

Since: base-2.1

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

(Applicative f, Applicative g) => Applicative (f :*: g)

Since: base-4.9.0.0

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, Monad f) => Applicative (WhenMissing f k x)

Equivalent to ReaderT k (ReaderT x (MaybeT f)) .

Since: containers-0.5.9

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

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

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

(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

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

class Applicative f => Alternative (f :: * -> *) 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

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

An associative binary operation

Instances

Alternative []

Since: base-2.1

Defined in GHC.Base

Methods

empty :: [a]

(<|>) :: [a] -> [a] -> [a]

some :: [a] -> [[a]]

many :: [a] -> [[a]]

Alternative Maybe

Since: base-2.1

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

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

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

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 (U1 :: * -> *)

Since: base-4.9.0.0

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

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

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 :: * -> *)

Since: base-4.9.0.0

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

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

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 f => Alternative (Alt f)

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)

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

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 (M1 i c f)

Since: base-4.9.0.0

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

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]

guard :: Alternative f => Bool -> f ()

Conditional failure of Alternative computations. Defined by

guard True  = pure ()
guard False = empty

Examples

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.

class Applicative m => Monad (m :: * -> *) 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 laws:

• return a >>= k  =  k a

• m >>= return  =  m

• m >>= (\x -> k x >>= h)  =  (m >>= k) >>= h

Furthermore, the Monad and Applicative operations should relate as follows:

• pure = return

• (<*>) = ap

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.

Minimal complete definition

(>>=)

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.

(>>) :: 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.

return :: a -> m a

Inject a value into the monadic type.

Instances

Monad []

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: [a] -> (a -> [b]) -> [b]

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

return :: a -> [a]

fail :: String -> [a]

Monad Maybe

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b

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

return :: a -> Maybe a

fail :: String -> Maybe a

Monad IO

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: IO a -> (a -> IO b) -> IO b

(>>) :: IO a -> IO b -> IO b

return :: a -> IO a

fail :: String -> IO a

Monad Par1

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

(>>=) :: Par1 a -> (a -> Par1 b) -> Par1 b

(>>) :: Par1 a -> Par1 b -> Par1 b

return :: a -> Par1 a

fail :: String -> Par1 a

Monad Min

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

(>>=) :: Min a -> (a -> Min b) -> Min b

(>>) :: Min a -> Min b -> Min b

return :: a -> Min a

fail :: String -> Min a

Monad Max

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

(>>=) :: Max a -> (a -> Max b) -> Max b

(>>) :: Max a -> Max b -> Max b

return :: a -> Max a

fail :: String -> Max a

Monad First

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

(>>=) :: First a -> (a -> First b) -> First b

(>>) :: First a -> First b -> First b

return :: a -> First a

fail :: String -> First a

Monad Last

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

(>>=) :: Last a -> (a -> Last b) -> Last b

(>>) :: Last a -> Last b -> Last b

return :: a -> Last a

fail :: String -> Last a

Monad Option

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

(>>=) :: Option a -> (a -> Option b) -> Option b

(>>) :: Option a -> Option b -> Option b

return :: a -> Option a

fail :: String -> Option a

Monad First

Defined in Data.Monoid

Methods

(>>=) :: First a -> (a -> First b) -> First b

(>>) :: First a -> First b -> First b

return :: a -> First a

fail :: String -> First a

Monad Last

Defined in Data.Monoid

Methods

(>>=) :: Last a -> (a -> Last b) -> Last b

(>>) :: Last a -> Last b -> Last b

return :: a -> Last a

fail :: String -> Last a

Monad Dual

Since: base-4.8.0.0

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Dual a -> (a -> Dual b) -> Dual b

(>>) :: Dual a -> Dual b -> Dual b

return :: a -> Dual a

fail :: String -> Dual a

Monad Sum

Since: base-4.8.0.0

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Sum a -> (a -> Sum b) -> Sum b

(>>) :: Sum a -> Sum b -> Sum b

return :: a -> Sum a

fail :: String -> Sum a

Monad Product

Since: base-4.8.0.0

Defined in Data.Semigroup.Internal

Methods

(>>=) :: Product a -> (a -> Product b) -> Product b

(>>) :: Product a -> Product b -> Product b

return :: a -> Product a

fail :: String -> Product a

Monad Down

Since: base-4.11.0.0

Defined in Data.Ord

Methods

(>>=) :: Down a -> (a -> Down b) -> Down b

(>>) :: Down a -> Down b -> Down b

return :: a -> Down a

fail :: String -> Down a

Monad NonEmpty

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(>>=) :: NonEmpty a -> (a -> NonEmpty b) -> NonEmpty b

(>>) :: NonEmpty a -> NonEmpty b -> NonEmpty b

return :: a -> NonEmpty a

fail :: String -> NonEmpty a

Monad (Either e)

Since: base-4.4.0.0

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

fail :: String -> Either e a

Monad (U1 :: * -> *)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

(>>=) :: U1 a -> (a -> U1 b) -> U1 b

(>>) :: U1 a -> U1 b -> U1 b

return :: a -> U1 a

fail :: String -> U1 a

Monoid a => Monad ((,) a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(>>=) :: (a, a0) -> (a0 -> (a, b)) -> (a, b)

(>>) :: (a, a0) -> (a, b) -> (a, b)

return :: a0 -> (a, a0)

fail :: String -> (a, a0)

Monad m => Monad (WrappedMonad m)

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

fail :: String -> WrappedMonad m a

ArrowApply a => Monad (ArrowMonad a)

Since: base-2.1

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

fail :: String -> ArrowMonad a a0

Monad (Proxy :: * -> *)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

(>>=) :: Proxy a -> (a -> Proxy b) -> Proxy b

(>>) :: Proxy a -> Proxy b -> Proxy b

return :: a -> Proxy a

fail :: String -> Proxy a

Monad (IParser t)

Defined in Data.Text.Internal.Read

Methods

(>>=) :: IParser t a -> (a -> IParser t b) -> IParser t b

(>>) :: IParser t a -> IParser t b -> IParser t b

return :: a -> IParser t a

fail :: String -> IParser t a

Monad f => Monad (Rec1 f)

Since: base-4.9.0.0

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

fail :: String -> Rec1 f a

Monad f => Monad (Alt f)

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

fail :: String -> Alt f a

(Monad m, Error e) => Monad (ErrorT e m)

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

fail :: String -> ErrorT e m a

Monad ((->) r :: * -> *)

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: (r -> a) -> (a -> r -> b) -> r -> b

(>>) :: (r -> a) -> (r -> b) -> r -> b

return :: a -> r -> a

fail :: String -> r -> a

(Monad f, Monad g) => Monad (f :*: g)

Since: base-4.9.0.0

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

fail :: String -> (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

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

fail :: String -> WhenMissing f k x a

Monad f => Monad (M1 i c f)

Since: base-4.9.0.0

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

fail :: String -> 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

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

fail :: String -> WhenMatched f k x y a

mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)

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

sequence :: (Traversable t, Monad m) => t (m a) -> m (t a)

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

unless :: Applicative f => Bool -> f () -> f ()

The reverse of when.

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

Like foldM, but discards the result.

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

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

Left-to-right Kleisli composition of monads.

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

This generalizes the list-based filter function.

forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b)

forM is mapM with its arguments flipped. For a version that ignores the results see forM_.

sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()

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

As of base 4.8.0.0, sequence_ is just sequenceA_, specialized to Monad.

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

forM_ is mapM_ with its arguments flipped. For a version that doesn't ignore the results see forM.

As of base 4.8.0.0, forM_ is just for_, specialized to Monad.

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

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

As of base 4.8.0.0, mapM_ is just traverse_, specialized to Monad.

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.

class (Alternative m, Monad m) => MonadPlus (m :: * -> *)

Monads that also support choice and failure.

Instances

MonadPlus []

Since: base-2.1

Defined in GHC.Base

Methods

mzero :: [a]

mplus :: [a] -> [a] -> [a]

MonadPlus Maybe

Since: base-2.1

Defined in GHC.Base

Methods

mzero :: Maybe a

mplus :: Maybe a -> Maybe a -> Maybe a

MonadPlus IO

Since: base-4.9.0.0

Defined in GHC.Base

Methods

mzero :: IO a

mplus :: IO a -> IO a -> IO a

MonadPlus Option

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

mzero :: Option a

mplus :: Option a -> Option a -> Option a

MonadPlus (U1 :: * -> *)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

mzero :: U1 a

mplus :: U1 a -> U1 a -> U1 a

(ArrowApply a, ArrowPlus a) => MonadPlus (ArrowMonad a)

Since: base-4.6.0.0

Defined in Control.Arrow

Methods

mzero :: ArrowMonad a a0

mplus :: ArrowMonad a a0 -> ArrowMonad a a0 -> ArrowMonad a a0

MonadPlus (Proxy :: * -> *)

Since: base-4.9.0.0

Defined in Data.Proxy

Methods

mzero :: Proxy a

mplus :: Proxy a -> Proxy a -> Proxy a

MonadPlus f => MonadPlus (Rec1 f)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

mzero :: Rec1 f a

mplus :: Rec1 f a -> Rec1 f a -> Rec1 f a

MonadPlus f => MonadPlus (Alt f)

Defined in Data.Semigroup.Internal

Methods

mzero :: Alt f a

mplus :: Alt f a -> Alt f a -> Alt f a

(Monad m, Error e) => MonadPlus (ErrorT e m)

Defined in Control.Monad.Trans.Error

Methods

mzero :: ErrorT e m a

mplus :: ErrorT e m a -> ErrorT e m a -> ErrorT e m a

(MonadPlus f, MonadPlus g) => MonadPlus (f :*: g)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

mzero :: (f :*: g) a

mplus :: (f :*: g) a -> (f :*: g) a -> (f :*: g) a

MonadPlus f => MonadPlus (M1 i c f)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

mzero :: M1 i c f a

mplus :: M1 i c f a -> M1 i c f a -> M1 i c f a

liftIO :: MonadIO m => IO a -> m a

Lift a computation from the IO monad.

class Bifunctor (p :: * -> * -> *) 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

>>> 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

>>> 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

>>> second (+1) ('j', 3)
('j',4)

>>> second (+1) (Right 3)
Right 4

Instances

Bifunctor Either

Since: base-4.8.0.0

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

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

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

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 :: * -> * -> *)

Since: base-4.8.0.0

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 :: * -> * -> *)

Since: base-4.9.0.0

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

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

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

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

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)

otherwise :: Bool

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

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

data Bool

Constructors

False

True

Instances

Bounded Bool

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Bool

maxBound :: Bool

Enum Bool

Since: base-2.1

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

Defined in GHC.Classes

Methods

(==) :: Bool -> Bool -> Bool

(/=) :: Bool -> Bool -> Bool

Ord Bool

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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Bool

readList :: ReadS [Bool]

readPrec :: ReadPrec Bool

readListPrec :: ReadPrec [Bool]

Show Bool

Defined in GHC.Show

Methods

showsPrec :: Int -> Bool -> ShowS

show :: Bool -> String

showList :: [Bool] -> ShowS

Ix Bool

Since: base-2.1

Defined in GHC.Arr

Methods

range :: (Bool, Bool) -> [Bool]

index :: (Bool, Bool) -> Bool -> Int

unsafeIndex :: (Bool, Bool) -> Bool -> Int

inRange :: (Bool, Bool) -> Bool -> Bool

rangeSize :: (Bool, Bool) -> Int

unsafeRangeSize :: (Bool, Bool) -> Int

Generic Bool

Defined in GHC.Generics

Associated Types

type Rep Bool :: * -> *

Methods

from :: Bool -> Rep Bool x

to :: Rep Bool x -> Bool

SingKind Bool

Since: base-4.9.0.0

Defined in GHC.Generics

Associated Types

type DemoteRep Bool :: *

Methods

fromSing :: Sing a -> DemoteRep Bool

SingI False

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

sing :: Sing False

SingI True

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

sing :: Sing True

type Rep Bool

Defined in GHC.Generics

type Rep Bool = D1 (MetaData "Bool" "GHC.Types" "ghc-prim" False) (C1 (MetaCons "False" PrefixI False) (U1 :: * -> *) :+: C1 (MetaCons "True" PrefixI False) (U1 :: * -> *))

data Sing (a :: Bool)

Defined in GHC.Generics

data Sing (a :: Bool) where

• STrue :: Sing True
• SFalse :: Sing False

type DemoteRep Bool

Defined in GHC.Generics

type DemoteRep Bool = Bool

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

Boolean "and"

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

Boolean "or"

not :: Bool -> Bool

Boolean "not"

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

Bounded Char

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Char

maxBound :: Char

Enum Char

Since: base-2.1

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

Defined in GHC.Classes

Methods

(==) :: Char -> Char -> Bool

(/=) :: Char -> Char -> Bool

Ord Char

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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Char

readList :: ReadS [Char]

readPrec :: ReadPrec Char

readListPrec :: ReadPrec [Char]

Show Char

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Char -> ShowS

show :: Char -> String

showList :: [Char] -> ShowS

Ix Char

Since: base-2.1

Defined in GHC.Arr

Methods

range :: (Char, Char) -> [Char]

index :: (Char, Char) -> Char -> Int

unsafeIndex :: (Char, Char) -> Char -> Int

inRange :: (Char, Char) -> Char -> Bool

rangeSize :: (Char, Char) -> Int

unsafeRangeSize :: (Char, Char) -> Int

ErrorList Char

Defined in Control.Monad.Trans.Error

Methods

listMsg :: String -> [Char]

Generic1 (URec Char :: k -> *)

Defined in GHC.Generics

Associated Types

type Rep1 (URec Char) :: k -> *

Methods

from1 :: URec Char a -> Rep1 (URec Char) a

to1 :: Rep1 (URec Char) a -> URec Char a

Functor (URec Char :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Char a -> URec Char b

(<$) :: a -> URec Char b -> URec Char a

Foldable (URec Char :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec Char m -> m

foldMap :: Monoid m => (a -> m) -> URec Char a -> m

foldr :: (a -> b -> b) -> b -> URec Char a -> b

foldr' :: (a -> b -> b) -> b -> URec Char a -> b

foldl :: (b -> a -> b) -> b -> URec Char a -> b

foldl' :: (b -> a -> b) -> b -> URec Char a -> b

foldr1 :: (a -> a -> a) -> URec Char a -> a

foldl1 :: (a -> a -> a) -> URec Char a -> a

toList :: URec Char a -> [a]

null :: URec Char a -> Bool

length :: URec Char a -> Int

elem :: Eq a => a -> URec Char a -> Bool

maximum :: Ord a => URec Char a -> a

minimum :: Ord a => URec Char a -> a

sum :: Num a => URec Char a -> a

product :: Num a => URec Char a -> a

Traversable (URec Char :: * -> *)

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> URec Char a -> f (URec Char b)

sequenceA :: Applicative f => URec Char (f a) -> f (URec Char a)

mapM :: Monad m => (a -> m b) -> URec Char a -> m (URec Char b)

sequence :: Monad m => URec Char (m a) -> m (URec Char a)

Eq (URec Char p)

Defined in GHC.Generics

Methods

(==) :: URec Char p -> URec Char p -> Bool

(/=) :: URec Char p -> URec Char p -> Bool

Ord (URec Char p)

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)

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)

Defined in GHC.Generics

Associated Types

type Rep (URec Char p) :: * -> *

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

Defined in GHC.Generics

data URec Char (p :: k) = UChar {

• uChar# :: Char#

}

type Rep1 (URec Char :: k -> *)

Defined in GHC.Generics

type Rep1 (URec Char :: k -> *) = D1 (MetaData "URec" "GHC.Generics" "base" False) (C1 (MetaCons "UChar" PrefixI True) (S1 (MetaSel (Just "uChar#") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (UChar :: k -> *)))

type Rep (URec Char p)

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 :: * -> *)))

digitToInt :: Char -> Int

Convert a single digit Char to the corresponding Int. This function fails unless its argument satisfies isHexDigit, but recognises both upper- and lower-case hexadecimal digits (that is, '0'..'9', 'a'..'f', 'A'..'F').

Examples

Characters '0' through '9' are converted properly to 0..9:

>>> map digitToInt ['0'..'9']
[0,1,2,3,4,5,6,7,8,9]

Both upper- and lower-case 'A' through 'F' are converted as well, to 10..15.

>>> map digitToInt ['a'..'f']
[10,11,12,13,14,15]
>>> map digitToInt ['A'..'F']
[10,11,12,13,14,15]

Anything else throws an exception:

>>> digitToInt 'G'
*** Exception: Char.digitToInt: not a digit 'G'
>>> digitToInt '♥'
*** Exception: Char.digitToInt: not a digit '\9829'

intToDigit :: Int -> Char

Convert an Int in the range 0..15 to the corresponding single digit Char. This function fails on other inputs, and generates lower-case hexadecimal digits.

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

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

Bifunctor Either

Since: base-4.8.0.0

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

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

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

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

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

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

fail :: String -> Either e a

Functor (Either a)

Since: base-3.0

Defined in Data.Either

Methods

fmap :: (a0 -> b) -> Either a a0 -> Either a b

(<$) :: a0 -> Either a b -> Either a a0

Applicative (Either e)

Since: base-3.0

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

Defined in Data.Foldable

Methods

fold :: Monoid m => Either a m -> 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

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

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

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

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

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 :: * -> *)

Defined in GHC.Generics

Associated Types

type Rep1 (Either a) :: k -> *

Methods

from1 :: Either a a0 -> Rep1 (Either a) a0

to1 :: Rep1 (Either a) a0 -> Either a a0

(Eq a, Eq b) => Eq (Either a b)

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)

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)

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)

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)

Defined in GHC.Generics

Associated Types

type Rep (Either a b) :: * -> *

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

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 :: * -> *)

Defined in GHC.Generics

type Rep1 (Either a :: * -> *) = 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)

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)))

isRight :: Either a b -> Bool

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

Examples

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

isLeft :: Either a b -> Bool

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

Examples

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

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

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

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

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

Examples

Basic usage:

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

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

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

Examples

Basic usage:

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

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

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

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.

Minimal complete definition: either == or /=.

Minimal complete definition

(==) | (/=)

Methods

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

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

Instances

Eq Bool

Defined in GHC.Classes

Methods

(==) :: Bool -> Bool -> Bool

(/=) :: Bool -> Bool -> Bool

Eq Char

Defined in GHC.Classes

Methods

(==) :: Char -> Char -> Bool

(/=) :: Char -> Char -> Bool

Eq Double

Defined in GHC.Classes

Methods

(==) :: Double -> Double -> Bool

(/=) :: Double -> Double -> Bool

Eq Float

Defined in GHC.Classes

Methods

(==) :: Float -> Float -> Bool

(/=) :: Float -> Float -> Bool

Eq Int

Defined in GHC.Classes

Methods

(==) :: Int -> Int -> Bool

(/=) :: Int -> Int -> Bool

Eq Int8

Since: base-2.1

Defined in GHC.Int

Methods

(==) :: Int8 -> Int8 -> Bool

(/=) :: Int8 -> Int8 -> Bool

Eq Int16

Since: base-2.1

Defined in GHC.Int

Methods

(==) :: Int16 -> Int16 -> Bool

(/=) :: Int16 -> Int16 -> Bool

Eq Int32

Since: base-2.1

Defined in GHC.Int

Methods

(==) :: Int32 -> Int32 -> Bool

(/=) :: Int32 -> Int32 -> Bool

Eq Int64

Since: base-2.1

Defined in GHC.Int

Methods

(==) :: Int64 -> Int64 -> Bool

(/=) :: Int64 -> Int64 -> Bool

Eq Integer

Defined in GHC.Integer.Type

Methods

(==) :: Integer -> Integer -> Bool

(/=) :: Integer -> Integer -> Bool

Eq Ordering

Defined in GHC.Classes

Methods

(==) :: Ordering -> Ordering -> Bool

(/=) :: Ordering -> Ordering -> Bool

Eq Word

Defined in GHC.Classes

Methods

(==) :: Word -> Word -> Bool

(/=) :: Word -> Word -> Bool

Eq ()

Defined in GHC.Classes

Methods

(==) :: () -> () -> Bool

(/=) :: () -> () -> Bool

Eq TyCon

Defined in GHC.Classes

Methods

(==) :: TyCon -> TyCon -> Bool

(/=) :: TyCon -> TyCon -> Bool

Eq Module

Defined in GHC.Classes

Methods

(==) :: Module -> Module -> Bool

(/=) :: Module -> Module -> Bool

Eq TrName

Defined in GHC.Classes

Methods

(==) :: TrName -> TrName -> Bool

(/=) :: TrName -> TrName -> Bool

Eq Handle

Since: base-4.1.0.0

Defined in GHC.IO.Handle.Types

Methods

(==) :: Handle -> Handle -> Bool

(/=) :: Handle -> Handle -> Bool

Eq BigNat

Defined in GHC.Integer.Type

Methods

(==) :: BigNat -> BigNat -> Bool

(/=) :: BigNat -> BigNat -> Bool

Eq SpecConstrAnnotation

Defined in GHC.Exts

Methods

(==) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool

(/=) :: SpecConstrAnnotation -> SpecConstrAnnotation -> Bool

Eq HandlePosn

Since: base-4.1.0.0

Defined in GHC.IO.Handle

Methods

(==) :: HandlePosn -> HandlePosn -> Bool

(/=) :: HandlePosn -> HandlePosn -> Bool

Eq AsyncException

Defined in GHC.IO.Exception

Methods

(==) :: AsyncException -> AsyncException -> Bool

(/=) :: AsyncException -> AsyncException -> Bool

Eq ArrayException

Defined in GHC.IO.Exception

Methods

(==) :: ArrayException -> ArrayException -> Bool

(/=) :: ArrayException -> ArrayException -> Bool

Eq ExitCode

Defined in GHC.IO.Exception

Methods

(==) :: ExitCode -> ExitCode -> Bool

(/=) :: ExitCode -> ExitCode -> Bool

Eq IOErrorType

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

(==) :: IOErrorType -> IOErrorType -> Bool

(/=) :: IOErrorType -> IOErrorType -> Bool

Eq BufferMode

Defined in GHC.IO.Handle.Types

Methods

(==) :: BufferMode -> BufferMode -> Bool

(/=) :: BufferMode -> BufferMode -> Bool

Eq Newline

Defined in GHC.IO.Handle.Types

Methods

(==) :: Newline -> Newline -> Bool

(/=) :: Newline -> Newline -> Bool

Eq NewlineMode

Defined in GHC.IO.Handle.Types

Methods

(==) :: NewlineMode -> NewlineMode -> Bool

(/=) :: NewlineMode -> NewlineMode -> Bool

Eq MaskingState

Defined in GHC.IO

Methods

(==) :: MaskingState -> MaskingState -> Bool

(/=) :: MaskingState -> MaskingState -> Bool

Eq IOException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

(==) :: IOException -> IOException -> Bool

(/=) :: IOException -> IOException -> Bool

Eq All

Defined in Data.Semigroup.Internal

Methods

(==) :: All -> All -> Bool

(/=) :: All -> All -> Bool

Eq Any

Defined in Data.Semigroup.Internal

Methods

(==) :: Any -> Any -> Bool

(/=) :: Any -> Any -> Bool

Eq Fixity

Defined in GHC.Generics

Methods

(==) :: Fixity -> Fixity -> Bool

(/=) :: Fixity -> Fixity -> Bool

Eq Associativity

Defined in GHC.Generics

Methods

(==) :: Associativity -> Associativity -> Bool

(/=) :: Associativity -> Associativity -> Bool

Eq SourceUnpackedness

Defined in GHC.Generics

Methods

(==) :: SourceUnpackedness -> SourceUnpackedness -> Bool

(/=) :: SourceUnpackedness -> SourceUnpackedness -> Bool

Eq SourceStrictness

Defined in GHC.Generics

Methods

(==) :: SourceStrictness -> SourceStrictness -> Bool

(/=) :: SourceStrictness -> SourceStrictness -> Bool

Eq DecidedStrictness

Defined in GHC.Generics

Methods

(==) :: DecidedStrictness -> DecidedStrictness -> Bool

(/=) :: DecidedStrictness -> DecidedStrictness -> Bool

Eq SrcLoc

Defined in GHC.Stack.Types

Methods

(==) :: SrcLoc -> SrcLoc -> Bool

(/=) :: SrcLoc -> SrcLoc -> Bool

Eq IntSet

Defined in Data.IntSet.Internal

Methods

(==) :: IntSet -> IntSet -> Bool

(/=) :: IntSet -> IntSet -> Bool

Eq LocalTime

Defined in Data.Time.LocalTime.Internal.LocalTime

Methods

(==) :: LocalTime -> LocalTime -> Bool

(/=) :: LocalTime -> LocalTime -> Bool

Eq UniversalTime

Defined in Data.Time.Clock.Internal.UniversalTime

Methods

(==) :: UniversalTime -> UniversalTime -> Bool

(/=) :: UniversalTime -> UniversalTime -> Bool

Eq UTCTime

Defined in Data.Time.Clock.Internal.UTCTime

Methods

(==) :: UTCTime -> UTCTime -> Bool

(/=) :: UTCTime -> UTCTime -> Bool

Eq Day

Defined in Data.Time.Calendar.Days

Methods

(==) :: Day -> Day -> Bool

(/=) :: Day -> Day -> Bool

Eq a => Eq [a]

Defined in GHC.Classes

Methods

(==) :: [a] -> [a] -> Bool

(/=) :: [a] -> [a] -> Bool

Eq a => Eq (Maybe a)

Defined in GHC.Base

Methods

(==) :: Maybe a -> Maybe a -> Bool

(/=) :: Maybe a -> Maybe a -> Bool

Eq a => Eq (Ratio a)

Defined in GHC.Real

Methods

(==) :: Ratio a -> Ratio a -> Bool

(/=) :: Ratio a -> Ratio a -> Bool

Eq (Ptr a)

Defined in GHC.Ptr

Methods

(==) :: Ptr a -> Ptr a -> Bool

(/=) :: Ptr a -> Ptr a -> Bool

Eq (FunPtr a)

Defined in GHC.Ptr

Methods

(==) :: FunPtr a -> FunPtr a -> Bool

(/=) :: FunPtr a -> FunPtr a -> Bool

Eq p => Eq (Par1 p)

Defined in GHC.Generics

Methods

(==) :: Par1 p -> Par1 p -> Bool

(/=) :: Par1 p -> Par1 p -> Bool

Eq a => Eq (Min a)

Defined in Data.Semigroup

Methods

(==) :: Min a -> Min a -> Bool

(/=) :: Min a -> Min a -> Bool

Eq a => Eq (Max a)

Defined in Data.Semigroup

Methods

(==) :: Max a -> Max a -> Bool

(/=) :: Max a -> Max a -> Bool

Eq a => Eq (First a)

Defined in Data.Semigroup

Methods

(==) :: First a -> First a -> Bool

(/=) :: First a -> First a -> Bool

Eq a => Eq (Last a)

Defined in Data.Semigroup

Methods

(==) :: Last a -> Last a -> Bool

(/=) :: Last a -> Last a -> Bool

Eq m => Eq (WrappedMonoid m)

Defined in Data.Semigroup

Methods

(==) :: WrappedMonoid m -> WrappedMonoid m -> Bool

(/=) :: WrappedMonoid m -> WrappedMonoid m -> Bool

Eq a => Eq (Option a)

Defined in Data.Semigroup

Methods

(==) :: Option a -> Option a -> Bool

(/=) :: Option a -> Option a -> Bool

Eq a => Eq (ZipList a)

Defined in Control.Applicative

Methods

(==) :: ZipList a -> ZipList a -> Bool

(/=) :: ZipList a -> ZipList a -> Bool

Eq a => Eq (First a)

Defined in Data.Monoid

Methods

(==) :: First a -> First a -> Bool

(/=) :: First a -> First a -> Bool

Eq a => Eq (Last a)

Defined in Data.Monoid

Methods

(==) :: Last a -> Last a -> Bool

(/=) :: Last a -> Last a -> Bool

Eq a => Eq (Dual a)

Defined in Data.Semigroup.Internal

Methods

(==) :: Dual a -> Dual a -> Bool

(/=) :: Dual a -> Dual a -> Bool

Eq a => Eq (Sum a)

Defined in Data.Semigroup.Internal

Methods

(==) :: Sum a -> Sum a -> Bool

(/=) :: Sum a -> Sum a -> Bool

Eq a => Eq (Product a)

Defined in Data.Semigroup.Internal

Methods

(==) :: Product a -> Product a -> Bool

(/=) :: Product a -> Product a -> Bool

Eq a => Eq (Down a)

Defined in Data.Ord

Methods

(==) :: Down a -> Down a -> Bool

(/=) :: Down a -> Down a -> Bool

Eq a => Eq (NonEmpty a)

Defined in GHC.Base

Methods

(==) :: NonEmpty a -> NonEmpty a -> Bool

(/=) :: NonEmpty a -> NonEmpty a -> Bool

Eq a => Eq (Set a)

Defined in Data.Set.Internal

Methods

(==) :: Set a -> Set a -> Bool

(/=) :: Set a -> Set a -> Bool

(Eq a, Eq b) => Eq (Either a b)

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

Defined in GHC.Generics

Methods

(==) :: V1 p -> V1 p -> Bool

(/=) :: V1 p -> V1 p -> Bool

Eq (U1 p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

(==) :: U1 p -> U1 p -> Bool

(/=) :: U1 p -> U1 p -> Bool

(Eq a, Eq b) => Eq (a, b)

Defined in GHC.Classes

Methods

(==) :: (a, b) -> (a, b) -> Bool

(/=) :: (a, b) -> (a, b) -> Bool

(Ix i, Eq e) => Eq (Array i e)

Since: base-2.1

Defined in GHC.Arr

Methods

(==) :: Array i e -> Array i e -> Bool

(/=) :: Array i e -> Array i e -> Bool

Eq a => Eq (Arg a b)

Since: base-4.9.0.0

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

Defined in Data.Proxy

Methods

(==) :: Proxy s -> Proxy s -> Bool

(/=) :: Proxy s -> Proxy s -> Bool

(Eq k, Eq a) => Eq (Map k a)

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)

Defined in GHC.Generics

Methods

(==) :: Rec1 f p -> Rec1 f p -> Bool

(/=) :: Rec1 f p -> Rec1 f p -> Bool

Eq (URec (Ptr ()) p)

Defined in GHC.Generics

Methods

(==) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool

(/=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool

Eq (URec Char p)

Defined in GHC.Generics

Methods

(==) :: URec Char p -> URec Char p -> Bool

(/=) :: URec Char p -> URec Char p -> Bool

Eq (URec Double p)

Defined in GHC.Generics

Methods

(==) :: URec Double p -> URec Double p -> Bool

(/=) :: URec Double p -> URec Double p -> Bool

Eq (URec Float p)

Defined in GHC.Generics

Methods

(==) :: URec Float p -> URec Float p -> Bool

(/=) :: URec Float p -> URec Float p -> Bool

Eq (URec Int p)

Defined in GHC.Generics

Methods

(==) :: URec Int p -> URec Int p -> Bool

(/=) :: URec Int p -> URec Int p -> Bool

Eq (URec Word p)

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)

Defined in GHC.Classes

Methods

(==) :: (a, b, c) -> (a, b, c) -> Bool

(/=) :: (a, b, c) -> (a, b, c) -> Bool

Eq (STArray s i e)

Since: base-2.1

Defined in GHC.Arr

Methods

(==) :: STArray s i e -> STArray s i e -> Bool

(/=) :: STArray s i e -> STArray s i e -> Bool

Eq (f a) => Eq (Alt f a)

Defined in Data.Semigroup.Internal

Methods

(==) :: Alt f a -> Alt f a -> Bool

(/=) :: Alt f a -> Alt f a -> Bool

Eq (a :~: b)

Defined in Data.Type.Equality

Methods

(==) :: (a :~: b) -> (a :~: b) -> Bool

(/=) :: (a :~: b) -> (a :~: b) -> Bool

(Eq e, Eq1 m, Eq a) => Eq (ErrorT e m a)

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)

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)

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)

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)

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d) -> (a, b, c, d) -> Bool

(/=) :: (a, b, c, d) -> (a, b, c, d) -> Bool

Eq (a :~~: b)

Since: base-4.10.0.0

Defined in Data.Type.Equality

Methods

(==) :: (a :~~: b) -> (a :~~: b) -> Bool

(/=) :: (a :~~: b) -> (a :~~: b) -> Bool

Eq (f p) => Eq (M1 i c f p)

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)

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)

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

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f) => Eq (a, b, c, d, e, f)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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 Foldable (t :: * -> *) 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.

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 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

foldr1 :: (a -> a -> a) -> t a -> a

A variant of foldr that has no base case, and thus may only be applied to non-empty structures.

foldr1 f = foldr1 f . toList

foldl1 :: (a -> a -> a) -> t a -> a

A variant of foldl that has no base case, and thus may only be applied to non-empty structures.

foldl1 f = foldl1 f . toList

null :: 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.

length :: 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.

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

Does the element occur in the structure?

maximum :: Ord a => t a -> a

The largest element of a non-empty structure.

minimum :: Ord a => t a -> a

The least element of a non-empty structure.

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

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

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

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

Instances

Foldable []

Since: base-2.1

Defined in Data.Foldable

Methods

fold :: Monoid m => [m] -> 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

Defined in Data.Foldable

Methods

fold :: Monoid m => Maybe m -> 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

Defined in Data.Foldable

Methods

fold :: Monoid m => Par1 m -> 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

Defined in Data.Semigroup

Methods

fold :: Monoid m => Min m -> 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

Defined in Data.Semigroup

Methods

fold :: Monoid m => Max m -> 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

Defined in Data.Semigroup

Methods

fold :: Monoid m => First m -> 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

Defined in Data.Semigroup

Methods

fold :: Monoid m => Last m -> 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

Defined in Data.Semigroup

Methods

fold :: Monoid m => Option m -> 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

Defined in Control.Applicative

Methods

fold :: Monoid m => ZipList m -> 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 First

Since: base-4.8.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => First m -> 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

Defined in Data.Foldable

Methods

fold :: Monoid m => Last m -> 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

Defined in Data.Foldable

Methods

fold :: Monoid m => Dual m -> 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

Defined in Data.Foldable

Methods

fold :: Monoid m => Sum m -> 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

Defined in Data.Foldable

Methods

fold :: Monoid m => Product m -> 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 NonEmpty

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => NonEmpty m -> 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

Defined in Data.Set.Internal

Methods

fold :: Monoid m => Set m -> 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

Defined in Data.Foldable

Methods

fold :: Monoid m => Either a m -> 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 :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => V1 m -> 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 :: * -> *)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => U1 m -> 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 ((,) a)

Since: base-4.7.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => (a, m) -> 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

Defined in Data.Foldable

Methods

fold :: Monoid m => Array i m -> 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

Defined in Data.Semigroup

Methods

fold :: Monoid m => Arg a m -> 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 :: * -> *)

Since: base-4.7.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => Proxy m -> 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)

Defined in Data.Map.Internal

Methods

fold :: Monoid m => Map k m -> 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)

Defined in Data.Foldable

Methods

fold :: Monoid m => Rec1 f m -> 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 (URec Char :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec Char m -> m

foldMap :: Monoid m => (a -> m) -> URec Char a -> m

foldr :: (a -> b -> b) -> b -> URec Char a -> b

foldr' :: (a -> b -> b) -> b -> URec Char a -> b

foldl :: (b -> a -> b) -> b -> URec Char a -> b

foldl' :: (b -> a -> b) -> b -> URec Char a -> b

foldr1 :: (a -> a -> a) -> URec Char a -> a

foldl1 :: (a -> a -> a) -> URec Char a -> a

toList :: URec Char a -> [a]

null :: URec Char a -> Bool

length :: URec Char a -> Int

elem :: Eq a => a -> URec Char a -> Bool

maximum :: Ord a => URec Char a -> a

minimum :: Ord a => URec Char a -> a

sum :: Num a => URec Char a -> a

product :: Num a => URec Char a -> a

Foldable (URec Double :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec Double m -> m

foldMap :: Monoid m => (a -> m) -> URec Double a -> m

foldr :: (a -> b -> b) -> b -> URec Double a -> b

foldr' :: (a -> b -> b) -> b -> URec Double a -> b

foldl :: (b -> a -> b) -> b -> URec Double a -> b

foldl' :: (b -> a -> b) -> b -> URec Double a -> b

foldr1 :: (a -> a -> a) -> URec Double a -> a

foldl1 :: (a -> a -> a) -> URec Double a -> a

toList :: URec Double a -> [a]

null :: URec Double a -> Bool

length :: URec Double a -> Int

elem :: Eq a => a -> URec Double a -> Bool

maximum :: Ord a => URec Double a -> a

minimum :: Ord a => URec Double a -> a

sum :: Num a => URec Double a -> a

product :: Num a => URec Double a -> a

Foldable (URec Float :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec Float m -> m

foldMap :: Monoid m => (a -> m) -> URec Float a -> m

foldr :: (a -> b -> b) -> b -> URec Float a -> b

foldr' :: (a -> b -> b) -> b -> URec Float a -> b

foldl :: (b -> a -> b) -> b -> URec Float a -> b

foldl' :: (b -> a -> b) -> b -> URec Float a -> b

foldr1 :: (a -> a -> a) -> URec Float a -> a

foldl1 :: (a -> a -> a) -> URec Float a -> a

toList :: URec Float a -> [a]

null :: URec Float a -> Bool

length :: URec Float a -> Int

elem :: Eq a => a -> URec Float a -> Bool

maximum :: Ord a => URec Float a -> a

minimum :: Ord a => URec Float a -> a

sum :: Num a => URec Float a -> a

product :: Num a => URec Float a -> a

Foldable (URec Int :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec Int m -> m

foldMap :: Monoid m => (a -> m) -> URec Int a -> m

foldr :: (a -> b -> b) -> b -> URec Int a -> b

foldr' :: (a -> b -> b) -> b -> URec Int a -> b

foldl :: (b -> a -> b) -> b -> URec Int a -> b

foldl' :: (b -> a -> b) -> b -> URec Int a -> b

foldr1 :: (a -> a -> a) -> URec Int a -> a

foldl1 :: (a -> a -> a) -> URec Int a -> a

toList :: URec Int a -> [a]

null :: URec Int a -> Bool

length :: URec Int a -> Int

elem :: Eq a => a -> URec Int a -> Bool

maximum :: Ord a => URec Int a -> a

minimum :: Ord a => URec Int a -> a

sum :: Num a => URec Int a -> a

product :: Num a => URec Int a -> a

Foldable (URec Word :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec Word m -> m

foldMap :: Monoid m => (a -> m) -> URec Word a -> m

foldr :: (a -> b -> b) -> b -> URec Word a -> b

foldr' :: (a -> b -> b) -> b -> URec Word a -> b

foldl :: (b -> a -> b) -> b -> URec Word a -> b

foldl' :: (b -> a -> b) -> b -> URec Word a -> b

foldr1 :: (a -> a -> a) -> URec Word a -> a

foldl1 :: (a -> a -> a) -> URec Word a -> a

toList :: URec Word a -> [a]

null :: URec Word a -> Bool

length :: URec Word a -> Int

elem :: Eq a => a -> URec Word a -> Bool

maximum :: Ord a => URec Word a -> a

minimum :: Ord a => URec Word a -> a

sum :: Num a => URec Word a -> a

product :: Num a => URec Word a -> a

Foldable (URec (Ptr ()) :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec (Ptr ()) m -> m

foldMap :: Monoid m => (a -> m) -> URec (Ptr ()) a -> m

foldr :: (a -> b -> b) -> b -> URec (Ptr ()) a -> b

foldr' :: (a -> b -> b) -> b -> URec (Ptr ()) a -> b

foldl :: (b -> a -> b) -> b -> URec (Ptr ()) a -> b

foldl' :: (b -> a -> b) -> b -> URec (Ptr ()) a -> b

foldr1 :: (a -> a -> a) -> URec (Ptr ()) a -> a

foldl1 :: (a -> a -> a) -> URec (Ptr ()) a -> a

toList :: URec (Ptr ()) a -> [a]

null :: URec (Ptr ()) a -> Bool

length :: URec (Ptr ()) a -> Int

elem :: Eq a => a -> URec (Ptr ()) a -> Bool

maximum :: Ord a => URec (Ptr ()) a -> a

minimum :: Ord a => URec (Ptr ()) a -> a

sum :: Num a => URec (Ptr ()) a -> a

product :: Num a => URec (Ptr ()) a -> a

Foldable f => Foldable (ErrorT e f)

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

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 :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => K1 i c m -> 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)

Defined in Data.Foldable

Methods

fold :: Monoid m => (f :+: g) m -> 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)

Defined in Data.Foldable

Methods

fold :: Monoid m => (f :*: g) m -> 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 (M1 i c f)

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

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)

Defined in Data.Foldable

Methods

fold :: Monoid m => (f :.: g) m -> 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

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.

minimumBy :: Foldable t => (a -> a -> Ordering) -> t a -> a

The least element of a non-empty structure with respect to the given comparison function.

maximumBy :: Foldable t => (a -> a -> Ordering) -> t a -> a

The largest element of a non-empty structure with respect to the given comparison function.

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

Determines whether all elements of the structure satisfy the predicate.

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

Determines whether any element of the structure satisfies the predicate.

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.

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.

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.

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

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.

($) :: (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.

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

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

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

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

(.) :: (b -> c) -> (a -> b) -> a -> c infixr 9

Function composition.

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]

id :: a -> a

Identity function.

id x = x

class Functor (f :: * -> *) where

The Functor class is used for types that can be mapped over. Instances of Functor should satisfy the following laws:

fmap id  ==  id
fmap (f . g)  ==  fmap f . fmap g

The instances of Functor for lists, Maybe and IO satisfy these laws.

Minimal complete definition

fmap

Methods

fmap :: (a -> b) -> f a -> f b

(<$) :: 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.

Instances

Functor []

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> [a] -> [b]

(<$) :: a -> [b] -> [a]

Functor Maybe

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> Maybe a -> Maybe b

(<$) :: a -> Maybe b -> Maybe a

Functor IO

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> IO a -> IO b

(<$) :: a -> IO b -> IO a

Functor Par1

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> Par1 a -> Par1 b

(<$) :: a -> Par1 b -> Par1 a

Functor Min

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Min a -> Min b

(<$) :: a -> Min b -> Min a

Functor Max

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Max a -> Max b

(<$) :: a -> Max b -> Max a

Functor First

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> First a -> First b

(<$) :: a -> First b -> First a

Functor Last

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Last a -> Last b

(<$) :: a -> Last b -> Last a

Functor Option

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

fmap :: (a -> b) -> Option a -> Option b

(<$) :: a -> Option b -> Option a

Functor ZipList

Defined in Control.Applicative

Methods

fmap :: (a -> b) -> ZipList a -> ZipList b

(<$) :: a -> ZipList b -> ZipList a

Functor First

Defined in Data.Monoid

Methods

fmap :: (a -> b) -> First a -> First b

(<$) :: a -> First b -> First a

Functor Last

Defined in Data.Monoid

Methods

fmap :: (a -> b) -> Last a -> Last b

(<$) :: a -> Last b -> Last a

Functor Dual

Since: base-4.8.0.0

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Dual a -> Dual b

(<$) :: a -> Dual b -> Dual a

Functor Sum

Since: base-4.8.0.0

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Sum a -> Sum b

(<$) :: a -> Sum b -> Sum a

Functor Product

Since: base-4.8.0.0

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Product a -> Product b

(<$) :: a -> Product b -> Product a

Functor Down

Since: base-4.11.0.0

Defined in Data.Ord

Methods

fmap :: (a -> b) -> Down a -> Down b

(<$) :: a -> Down b -> Down a

Functor NonEmpty

Since: base-4.9.0.0

Defined in GHC.Base

Methods

fmap :: (a -> b) -> NonEmpty a -> NonEmpty b

(<$) :: a -> NonEmpty b -> NonEmpty a

Functor (Either a)

Since: base-3.0

Defined in Data.Either

Methods

fmap :: (a0 -> b) -> Either a a0 -> Either a b

(<$) :: a0 -> Either a b -> Either a a0

Functor (V1 :: * -> *)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> V1 a -> V1 b

(<$) :: a -> V1 b -> V1 a

Functor (U1 :: * -> *)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> U1 a -> U1 b

(<$) :: a -> U1 b -> U1 a

Functor ((,) a)

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a0 -> b) -> (a, a0) -> (a, b)

(<$) :: a0 -> (a, b) -> (a, a0)

Functor (Array i)

Since: base-2.1

Defined in GHC.Arr

Methods

fmap :: (a -> b) -> Array i a -> Array i b

(<$) :: a -> Array i b -> Array i a

Functor (Arg a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

fmap :: (a0 -> b) -> Arg a a0 -> Arg a b

(<$) :: a0 -> Arg a b -> Arg a a0

Monad m => Functor (WrappedMonad m)

Since: base-2.1

Defined in Control.Applicative

Methods

fmap :: (a -> b) -> WrappedMonad m a -> WrappedMonad m b

(<$) :: a -> WrappedMonad m b -> WrappedMonad m a

Arrow a => Functor (ArrowMonad a)

Since: base-4.6.0.0

Defined in Control.Arrow

Methods

fmap :: (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b

(<$) :: a0 -> ArrowMonad a b -> ArrowMonad a a0

Functor (Proxy :: * -> *)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

fmap :: (a -> b) -> Proxy a -> Proxy b

(<$) :: a -> Proxy b -> Proxy a

Functor (Map k)

Defined in Data.Map.Internal

Methods

fmap :: (a -> b) -> Map k a -> Map k b

(<$) :: a -> Map k b -> Map k a

Functor (IParser t)

Defined in Data.Text.Internal.Read

Methods

fmap :: (a -> b) -> IParser t a -> IParser t b

(<$) :: a -> IParser t b -> IParser t a

Functor f => Functor (Rec1 f)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> Rec1 f a -> Rec1 f b

(<$) :: a -> Rec1 f b -> Rec1 f a

Functor (URec Char :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Char a -> URec Char b

(<$) :: a -> URec Char b -> URec Char a

Functor (URec Double :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Double a -> URec Double b

(<$) :: a -> URec Double b -> URec Double a

Functor (URec Float :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Float a -> URec Float b

(<$) :: a -> URec Float b -> URec Float a

Functor (URec Int :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Int a -> URec Int b

(<$) :: a -> URec Int b -> URec Int a

Functor (URec Word :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Word a -> URec Word b

(<$) :: a -> URec Word b -> URec Word a

Functor (URec (Ptr ()) :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec (Ptr ()) a -> URec (Ptr ()) b

(<$) :: a -> URec (Ptr ()) b -> URec (Ptr ()) a

Arrow a => Functor (WrappedArrow a b)

Since: base-2.1

Defined in Control.Applicative

Methods

fmap :: (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0

(<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0

Functor f => Functor (Alt f)

Defined in Data.Semigroup.Internal

Methods

fmap :: (a -> b) -> Alt f a -> Alt f b

(<$) :: a -> Alt f b -> Alt f a

Functor m => Functor (ErrorT e m)

Defined in Control.Monad.Trans.Error

Methods

fmap :: (a -> b) -> ErrorT e m a -> ErrorT e m b

(<$) :: a -> ErrorT e m b -> ErrorT e m a

Functor ((->) r :: * -> *)

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> (r -> a) -> r -> b

(<$) :: a -> (r -> b) -> r -> a

Functor (K1 i c :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> K1 i c a -> K1 i c b

(<$) :: a -> K1 i c b -> K1 i c a

(Functor f, Functor g) => Functor (f :+: g)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> (f :+: g) a -> (f :+: g) b

(<$) :: a -> (f :+: g) b -> (f :+: g) a

(Functor f, Functor g) => Functor (f :*: g)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> (f :*: g) a -> (f :*: g) b

(<$) :: a -> (f :*: g) b -> (f :*: g) a

(Applicative f, Monad f) => Functor (WhenMissing f k x)

Since: containers-0.5.9

Defined in Data.Map.Internal

Methods

fmap :: (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b

(<$) :: a -> WhenMissing f k x b -> WhenMissing f k x a

Functor f => Functor (M1 i c f)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> M1 i c f a -> M1 i c f b

(<$) :: a -> M1 i c f b -> M1 i c f a

(Functor f, Functor g) => Functor (f :.: g)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> (f :.: g) a -> (f :.: g) b

(<$) :: a -> (f :.: g) b -> (f :.: g) a

Functor f => Functor (WhenMatched f k x y)

Since: containers-0.5.9

Defined in Data.Map.Internal

Methods

fmap :: (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b

(<$) :: a -> WhenMatched f k x y b -> WhenMatched f k x y a

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

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

Examples

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

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

Flipped version of <$.

Examples

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

(<$>) :: 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

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)

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

Bounded Int

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Int

maxBound :: Int

Enum Int

Since: base-2.1

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

Defined in GHC.Classes

Methods

(==) :: Int -> Int -> Bool

(/=) :: Int -> Int -> Bool

Integral Int

Since: base-2.0.1

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

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

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

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

Defined in GHC.Real

Methods

toRational :: Int -> Rational

Show Int

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Int -> ShowS

show :: Int -> String

showList :: [Int] -> ShowS

Ix Int

Since: base-2.1

Defined in GHC.Arr

Methods

range :: (Int, Int) -> [Int]

index :: (Int, Int) -> Int -> Int

unsafeIndex :: (Int, Int) -> Int -> Int

inRange :: (Int, Int) -> Int -> Bool

rangeSize :: (Int, Int) -> Int

unsafeRangeSize :: (Int, Int) -> Int

Generic1 (URec Int :: k -> *)

Defined in GHC.Generics

Associated Types

type Rep1 (URec Int) :: k -> *

Methods

from1 :: URec Int a -> Rep1 (URec Int) a

to1 :: Rep1 (URec Int) a -> URec Int a

Functor (URec Int :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Int a -> URec Int b

(<$) :: a -> URec Int b -> URec Int a

Foldable (URec Int :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec Int m -> m

foldMap :: Monoid m => (a -> m) -> URec Int a -> m

foldr :: (a -> b -> b) -> b -> URec Int a -> b

foldr' :: (a -> b -> b) -> b -> URec Int a -> b

foldl :: (b -> a -> b) -> b -> URec Int a -> b

foldl' :: (b -> a -> b) -> b -> URec Int a -> b

foldr1 :: (a -> a -> a) -> URec Int a -> a

foldl1 :: (a -> a -> a) -> URec Int a -> a

toList :: URec Int a -> [a]

null :: URec Int a -> Bool

length :: URec Int a -> Int

elem :: Eq a => a -> URec Int a -> Bool

maximum :: Ord a => URec Int a -> a

minimum :: Ord a => URec Int a -> a

sum :: Num a => URec Int a -> a

product :: Num a => URec Int a -> a

Traversable (URec Int :: * -> *)

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> URec Int a -> f (URec Int b)

sequenceA :: Applicative f => URec Int (f a) -> f (URec Int a)

mapM :: Monad m => (a -> m b) -> URec Int a -> m (URec Int b)

sequence :: Monad m => URec Int (m a) -> m (URec Int a)

Eq (URec Int p)

Defined in GHC.Generics

Methods

(==) :: URec Int p -> URec Int p -> Bool

(/=) :: URec Int p -> URec Int p -> Bool

Ord (URec Int p)

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)

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)

Defined in GHC.Generics

Associated Types

type Rep (URec Int p) :: * -> *

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

Defined in GHC.Generics

data URec Int (p :: k) = UInt {

• uInt# :: Int#

}

type Rep1 (URec Int :: k -> *)

Defined in GHC.Generics

type Rep1 (URec Int :: k -> *) = D1 (MetaData "URec" "GHC.Generics" "base" False) (C1 (MetaCons "UInt" PrefixI True) (S1 (MetaSel (Just "uInt#") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (UInt :: k -> *)))

type Rep (URec Int p)

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 :: * -> *)))

data Int8

8-bit signed integer type

Instances

Bounded Int8

Since: base-2.1

Defined in GHC.Int

Methods

minBound :: Int8

maxBound :: Int8

Enum Int8

Since: base-2.1

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

Defined in GHC.Int

Methods

(==) :: Int8 -> Int8 -> Bool

(/=) :: Int8 -> Int8 -> Bool

Integral Int8

Since: base-2.1

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

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

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

Defined in GHC.Int

Methods

readsPrec :: Int -> ReadS Int8

readList :: ReadS [Int8]

readPrec :: ReadPrec Int8

readListPrec :: ReadPrec [Int8]

Real Int8

Since: base-2.1

Defined in GHC.Int

Methods

toRational :: Int8 -> Rational

Show Int8

Since: base-2.1

Defined in GHC.Int

Methods

showsPrec :: Int -> Int8 -> ShowS

show :: Int8 -> String

showList :: [Int8] -> ShowS

Ix Int8

Since: base-2.1

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

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

Defined in GHC.Int

Methods

finiteBitSize :: Int8 -> Int

countLeadingZeros :: Int8 -> Int

countTrailingZeros :: Int8 -> Int

data Int16

16-bit signed integer type

Instances

Bounded Int16

Since: base-2.1

Defined in GHC.Int

Methods

minBound :: Int16

maxBound :: Int16

Enum Int16

Since: base-2.1

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

Defined in GHC.Int

Methods

(==) :: Int16 -> Int16 -> Bool

(/=) :: Int16 -> Int16 -> Bool

Integral Int16

Since: base-2.1

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

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

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

Defined in GHC.Int

Methods

readsPrec :: Int -> ReadS Int16

readList :: ReadS [Int16]

readPrec :: ReadPrec Int16

readListPrec :: ReadPrec [Int16]

Real Int16

Since: base-2.1

Defined in GHC.Int

Methods

toRational :: Int16 -> Rational

Show Int16

Since: base-2.1

Defined in GHC.Int

Methods

showsPrec :: Int -> Int16 -> ShowS

show :: Int16 -> String

showList :: [Int16] -> ShowS

Ix Int16

Since: base-2.1

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

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

Defined in GHC.Int

Methods

finiteBitSize :: Int16 -> Int

countLeadingZeros :: Int16 -> Int

countTrailingZeros :: Int16 -> Int

data Int32

32-bit signed integer type

Instances

Bounded Int32

Since: base-2.1

Defined in GHC.Int

Methods

minBound :: Int32

maxBound :: Int32

Enum Int32

Since: base-2.1

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

Defined in GHC.Int

Methods

(==) :: Int32 -> Int32 -> Bool

(/=) :: Int32 -> Int32 -> Bool

Integral Int32

Since: base-2.1

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

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

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

Defined in GHC.Int

Methods

readsPrec :: Int -> ReadS Int32

readList :: ReadS [Int32]

readPrec :: ReadPrec Int32

readListPrec :: ReadPrec [Int32]

Real Int32

Since: base-2.1

Defined in GHC.Int

Methods

toRational :: Int32 -> Rational

Show Int32

Since: base-2.1

Defined in GHC.Int

Methods

showsPrec :: Int -> Int32 -> ShowS

show :: Int32 -> String

showList :: [Int32] -> ShowS

Ix Int32

Since: base-2.1

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

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

Defined in GHC.Int

Methods

finiteBitSize :: Int32 -> Int

countLeadingZeros :: Int32 -> Int

countTrailingZeros :: Int32 -> Int

data Int64

64-bit signed integer type

Instances

Bounded Int64

Since: base-2.1

Defined in GHC.Int

Methods

minBound :: Int64

maxBound :: Int64

Enum Int64

Since: base-2.1

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

Defined in GHC.Int

Methods

(==) :: Int64 -> Int64 -> Bool

(/=) :: Int64 -> Int64 -> Bool

Integral Int64

Since: base-2.1

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

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

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

Defined in GHC.Int

Methods

readsPrec :: Int -> ReadS Int64

readList :: ReadS [Int64]

readPrec :: ReadPrec Int64

readListPrec :: ReadPrec [Int64]

Real Int64

Since: base-2.1

Defined in GHC.Int

Methods

toRational :: Int64 -> Rational

Show Int64

Since: base-2.1

Defined in GHC.Int

Methods

showsPrec :: Int -> Int64 -> ShowS

show :: Int64 -> String

showList :: [Int64] -> ShowS

Ix Int64

Since: base-2.1

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

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

Defined in GHC.Int

Methods

finiteBitSize :: Int64 -> Int

countLeadingZeros :: Int64 -> Int

countTrailingZeros :: Int64 -> Int

data IntSet

A set of integers.

Instances

IsList IntSet

Since: containers-0.5.6.2

Defined in Data.IntSet.Internal

Associated Types

type Item IntSet :: *

Methods

fromList :: [Item IntSet] -> IntSet

fromListN :: Int -> [Item IntSet] -> IntSet

toList :: IntSet -> [Item IntSet]

Eq IntSet

Defined in Data.IntSet.Internal

Methods

(==) :: IntSet -> IntSet -> Bool

(/=) :: IntSet -> IntSet -> Bool

Data IntSet

Defined in Data.IntSet.Internal

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> IntSet -> c IntSet

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c IntSet

toConstr :: IntSet -> Constr

dataTypeOf :: IntSet -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c IntSet)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c IntSet)

gmapT :: (forall b. Data b => b -> b) -> IntSet -> IntSet

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> IntSet -> r

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> IntSet -> r

gmapQ :: (forall d. Data d => d -> u) -> IntSet -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> IntSet -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> IntSet -> m IntSet

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> IntSet -> m IntSet

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> IntSet -> m IntSet

Ord IntSet

Defined in Data.IntSet.Internal

Methods

compare :: IntSet -> IntSet -> Ordering

(<) :: IntSet -> IntSet -> Bool

(<=) :: IntSet -> IntSet -> Bool

(>) :: IntSet -> IntSet -> Bool

(>=) :: IntSet -> IntSet -> Bool

max :: IntSet -> IntSet -> IntSet

min :: IntSet -> IntSet -> IntSet

Read IntSet

Defined in Data.IntSet.Internal

Methods

readsPrec :: Int -> ReadS IntSet

readList :: ReadS [IntSet]

readPrec :: ReadPrec IntSet

readListPrec :: ReadPrec [IntSet]

Show IntSet

Defined in Data.IntSet.Internal

Methods

showsPrec :: Int -> IntSet -> ShowS

show :: IntSet -> String

showList :: [IntSet] -> ShowS

Semigroup IntSet

Since: containers-0.5.7

Defined in Data.IntSet.Internal

Methods

(<>) :: IntSet -> IntSet -> IntSet

sconcat :: NonEmpty IntSet -> IntSet

stimes :: Integral b => b -> IntSet -> IntSet

Monoid IntSet

Defined in Data.IntSet.Internal

Methods

mempty :: IntSet

mappend :: IntSet -> IntSet -> IntSet

mconcat :: [IntSet] -> IntSet

NFData IntSet

Defined in Data.IntSet.Internal

Methods

rnf :: IntSet -> ()

type Item IntSet

Defined in Data.IntSet.Internal

type Item IntSet = Key

data Map k a

A Map from keys k to values a.

Instances

Eq2 Map

Since: containers-0.5.9

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

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

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)

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)

Defined in Data.Map.Internal

Methods

fold :: Monoid m => Map k m -> 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)

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

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

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

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

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

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)

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)

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 :: (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)

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)

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)

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)

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)

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)

Defined in Data.Map.Internal

Methods

rnf :: Map k a -> ()

type Item (Map k v)

Defined in Data.Map.Internal

type Item (Map k v) = (k, v)

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

Monad Maybe

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b

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

return :: a -> Maybe a

fail :: String -> Maybe a

Functor Maybe

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> Maybe a -> Maybe b

(<$) :: a -> Maybe b -> Maybe a

Applicative Maybe

Since: base-2.1

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

Defined in Data.Foldable

Methods

fold :: Monoid m => Maybe m -> 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

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

Defined in Data.Functor.Classes

Methods

liftEq :: (a -> b -> Bool) -> Maybe a -> Maybe b -> Bool

Ord1 Maybe

Since: base-4.9.0.0

Defined in Data.Functor.Classes

Methods

liftCompare :: (a -> b -> Ordering) -> Maybe a -> Maybe b -> Ordering

Read1 Maybe

Since: base-4.9.0.0

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

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

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

Defined in GHC.Base

Methods

mzero :: Maybe a

mplus :: Maybe a -> Maybe a -> Maybe a

Eq a => Eq (Maybe a)

Defined in GHC.Base

Methods

(==) :: Maybe a -> Maybe a -> Bool

(/=) :: Maybe a -> Maybe a -> Bool

Ord a => Ord (Maybe a)

Defined in GHC.Base

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

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)

Defined in GHC.Show

Methods

showsPrec :: Int -> Maybe a -> ShowS

show :: Maybe a -> String

showList :: [Maybe a] -> ShowS

Generic (Maybe a)

Defined in GHC.Generics

Associated Types

type Rep (Maybe a) :: * -> *

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

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 e*e = e and e*s = s = s*e for all s ∈ S."

Since 4.11.0: constraint on inner a value generalised from Monoid to Semigroup.

Since: base-2.1

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

Defined in GHC.Generics

Associated Types

type DemoteRep (Maybe a) :: *

Methods

fromSing :: Sing a0 -> DemoteRep (Maybe a)

Generic1 Maybe

Defined in GHC.Generics

Associated Types

type Rep1 Maybe :: k -> *

Methods

from1 :: Maybe a -> Rep1 Maybe a

to1 :: Rep1 Maybe a -> Maybe a

SingI (Nothing :: Maybe a)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

sing :: Sing Nothing

SingI a2 => SingI (Just a2 :: Maybe a1)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

sing :: Sing (Just a2)

type Rep (Maybe a)

Defined in GHC.Generics

type Rep (Maybe a) = D1 (MetaData "Maybe" "GHC.Base" "base" False) (C1 (MetaCons "Nothing" PrefixI False) (U1 :: * -> *) :+: C1 (MetaCons "Just" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 a)))

data Sing (b :: Maybe a)

Defined in GHC.Generics

data Sing (b :: Maybe a) where

• SNothing :: Sing (Nothing :: Maybe a)
• SJust :: Sing (Just a1)

type DemoteRep (Maybe a)

Defined in GHC.Generics

type DemoteRep (Maybe a) = Maybe (DemoteRep a)

type Rep1 Maybe

Defined in GHC.Generics

type Rep1 Maybe = D1 (MetaData "Maybe" "GHC.Base" "base" False) (C1 (MetaCons "Nothing" PrefixI False) (U1 :: * -> *) :+: C1 (MetaCons "Just" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) Par1))

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

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

Examples

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]

listToMaybe :: [a] -> Maybe a

The listToMaybe function returns Nothing on an empty list or Just a where a is the first element of the list.

Examples

Basic usage:

>>> listToMaybe []
Nothing

>>> listToMaybe [9]
Just 9

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

Composing maybeToList with listToMaybe should be the identity on singleton/empty lists:

>>> maybeToList $ listToMaybe [5]
[5]
>>> maybeToList $ listToMaybe []
[]

But not on lists with more than one element:

>>> maybeToList $ listToMaybe [1,2,3]
[1]

maybeToList :: Maybe a -> [a]

The maybeToList function returns an empty list when given Nothing or a singleton list when not given Nothing.

Examples

Basic usage:

>>> maybeToList (Just 7)
[7]

>>> maybeToList Nothing
[]

One can use maybeToList to avoid pattern matching when combined with a function that (safely) works on lists:

>>> import Text.Read ( readMaybe )
>>> sum $ maybeToList (readMaybe "3")
3
>>> sum $ maybeToList (readMaybe "")
0

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

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

isNothing :: Maybe a -> Bool

The isNothing function returns True iff its argument is Nothing.

Examples

Basic usage:

>>> isNothing (Just 3)
False

>>> isNothing (Just ())
False

>>> isNothing Nothing
True

Only the outer constructor is taken into consideration:

>>> isNothing (Just Nothing)
False

isJust :: Maybe a -> Bool

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

Examples

Basic usage:

>>> isJust (Just 3)
True

>>> isJust (Just ())
True

>>> isJust Nothing
False

Only the outer constructor is taken into consideration:

>>> isJust (Just Nothing)
True

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

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
""

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 laws:

• x <> mempty = x

• mempty <> x = x

• x <> (y <> z) = (x <> y) <> z (Semigroup law)

• 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

mappend :: a -> a -> a

An associative operation

NOTE: This method is redundant and has the default implementation mappend = '(<>)' since base-4.11.0.0.

Instances

Monoid Ordering

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: Ordering

mappend :: Ordering -> Ordering -> Ordering

mconcat :: [Ordering] -> Ordering

Monoid ()

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: ()

mappend :: () -> () -> ()

mconcat :: [()] -> ()

Monoid All

Since: base-2.1

Defined in Data.Semigroup.Internal

Methods

mempty :: All

mappend :: All -> All -> All

mconcat :: [All] -> All

Monoid Any

Since: base-2.1

Defined in Data.Semigroup.Internal

Methods

mempty :: Any

mappend :: Any -> Any -> Any

mconcat :: [Any] -> Any

Monoid IntSet

Defined in Data.IntSet.Internal

Methods

mempty :: IntSet

mappend :: IntSet -> IntSet -> IntSet

mconcat :: [IntSet] -> IntSet

Monoid [a]

Since: base-2.1

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 e*e = e and e*s = s = s*e for all s ∈ S."

Since 4.11.0: constraint on inner a value generalised from Monoid to Semigroup.

Since: base-2.1

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

Defined in GHC.Base

Methods

mempty :: IO a

mappend :: IO a -> IO a -> IO a

mconcat :: [IO a] -> IO a

(Ord a, Bounded a) => Monoid (Min a)

Since: base-4.9.0.0

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

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

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

Defined in Data.Semigroup

Methods

mempty :: Option a

mappend :: Option a -> Option a -> Option a

mconcat :: [Option a] -> Option a

Monoid (First a)

Since: base-2.1

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

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

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

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

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

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

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)

Defined in Data.Set.Internal

Methods

mempty :: Set a

mappend :: Set a -> Set a -> Set a

mconcat :: [Set a] -> Set a

Monoid (MergeSet a)

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

Defined in GHC.Base

Methods

mempty :: a -> b

mappend :: (a -> b) -> (a -> b) -> a -> b

mconcat :: [a -> b] -> a -> b

(Monoid a, Monoid b) => Monoid (a, b)

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: (a, b)

mappend :: (a, b) -> (a, b) -> (a, b)

mconcat :: [(a, b)] -> (a, b)

Monoid (Proxy s)

Since: base-4.7.0.0

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)

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 a, Monoid b, Monoid c) => Monoid (a, b, c)

Since: base-2.1

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)

Alternative f => Monoid (Alt f a)

Since: base-4.8.0.0

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 a, Monoid b, Monoid c, Monoid d) => Monoid (a, b, c, d)

Since: base-2.1

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 a, Monoid b, Monoid c, Monoid d, Monoid e) => Monoid (a, b, c, d, e)

Since: base-2.1

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)

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.

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

Ord Bool

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

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

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

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

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

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

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

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

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

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 Ordering

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

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 ()

Defined in GHC.Classes

Methods

compare :: () -> () -> Ordering

(<) :: () -> () -> Bool

(<=) :: () -> () -> Bool

(>) :: () -> () -> Bool

(>=) :: () -> () -> Bool

max :: () -> () -> ()

min :: () -> () -> ()

Ord TyCon

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 BigNat

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 AsyncException

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

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

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

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

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

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 All

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

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

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

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

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

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

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 IntSet

Defined in Data.IntSet.Internal

Methods

compare :: IntSet -> IntSet -> Ordering

(<) :: IntSet -> IntSet -> Bool

(<=) :: IntSet -> IntSet -> Bool

(>) :: IntSet -> IntSet -> Bool

(>=) :: IntSet -> IntSet -> Bool

max :: IntSet -> IntSet -> IntSet

min :: IntSet -> IntSet -> IntSet

Ord LocalTime

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 UniversalTime

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

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 Day

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 a => Ord [a]

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)

Defined in GHC.Base

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

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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 (First a)

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)

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)

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)

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)

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

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)

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)

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)

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

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-4.9.0.0

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 a, Ord b) => Ord (a, b)

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)

(Ix i, Ord e) => Ord (Array i e)

Since: base-2.1

Defined in GHC.Arr

Methods

compare :: Array i e -> Array i e -> Ordering

(<) :: Array i e -> Array i e -> Bool

(<=) :: Array i e -> Array i e -> Bool

(>) :: Array i e -> Array i e -> Bool

(>=) :: Array i e -> Array i e -> Bool

max :: Array i e -> Array i e -> Array i e

min :: Array i e -> Array i e -> Array i e

Ord a => Ord (Arg a b)

Since: base-4.9.0.0

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

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)

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)

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)

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)

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)

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)

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)

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)

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)

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 (f a) => Ord (Alt f a)

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 (a :~: b)

Defined in Data.Type.Equality

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 e, Ord1 m, Ord a) => Ord (ErrorT e m a)

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)

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)

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)

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)

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)

Ord (a :~~: b)

Since: base-4.10.0.0

Defined in Data.Type.Equality

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 (f p) => Ord (M1 i c f p)

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)

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)

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)

(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f) => Ord (a, b, c, d, e, f)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

data Ordering

Constructors

LT

EQ

GT

Instances

Bounded Ordering

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Ordering

maxBound :: Ordering

Enum Ordering

Since: base-2.1

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

Defined in GHC.Classes

Methods

(==) :: Ordering -> Ordering -> Bool

(/=) :: Ordering -> Ordering -> Bool

Ord Ordering

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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Ordering

readList :: ReadS [Ordering]

readPrec :: ReadPrec Ordering

readListPrec :: ReadPrec [Ordering]

Show Ordering

Defined in GHC.Show

Methods

showsPrec :: Int -> Ordering -> ShowS

show :: Ordering -> String

showList :: [Ordering] -> ShowS

Ix Ordering

Since: base-2.1

Defined in GHC.Arr

Methods

range :: (Ordering, Ordering) -> [Ordering]

index :: (Ordering, Ordering) -> Ordering -> Int

unsafeIndex :: (Ordering, Ordering) -> Ordering -> Int

inRange :: (Ordering, Ordering) -> Ordering -> Bool

rangeSize :: (Ordering, Ordering) -> Int

unsafeRangeSize :: (Ordering, Ordering) -> Int

Generic Ordering

Defined in GHC.Generics

Associated Types

type Rep Ordering :: * -> *

Methods

from :: Ordering -> Rep Ordering x

to :: Rep Ordering x -> Ordering

Semigroup Ordering

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: Ordering -> Ordering -> Ordering

sconcat :: NonEmpty Ordering -> Ordering

stimes :: Integral b => b -> Ordering -> Ordering

Monoid Ordering

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: Ordering

mappend :: Ordering -> Ordering -> Ordering

mconcat :: [Ordering] -> Ordering

type Rep Ordering

Defined in GHC.Generics

type Rep Ordering = D1 (MetaData "Ordering" "GHC.Types" "ghc-prim" False) (C1 (MetaCons "LT" PrefixI False) (U1 :: * -> *) :+: (C1 (MetaCons "EQ" PrefixI False) (U1 :: * -> *) :+: C1 (MetaCons "GT" PrefixI False) (U1 :: * -> *)))

class Semigroup a where

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

Instances should satisfy the associativity law:

• x <> (y <> z) = (x <> y) <> z

Since: base-4.9.0.0

Minimal complete definition

(<>)

Methods

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

An associative operation.

Instances

Semigroup Ordering

Since: base-4.9.0.0

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

Defined in GHC.Base

Methods

(<>) :: () -> () -> ()

sconcat :: NonEmpty () -> ()

stimes :: Integral b => b -> () -> ()

Semigroup All

Since: base-4.9.0.0

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

Defined in Data.Semigroup.Internal

Methods

(<>) :: Any -> Any -> Any

sconcat :: NonEmpty Any -> Any

stimes :: Integral b => b -> Any -> Any

Semigroup IntSet

Since: containers-0.5.7

Defined in Data.IntSet.Internal

Methods

(<>) :: IntSet -> IntSet -> IntSet

sconcat :: NonEmpty IntSet -> IntSet

stimes :: Integral b => b -> IntSet -> IntSet

Semigroup [a]

Since: base-4.9.0.0

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

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

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

Ord a => Semigroup (Min a)

Since: base-4.9.0.0

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

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

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

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

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

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 (First a)

Since: base-4.9.0.0

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

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

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

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

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

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

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

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

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)

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

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

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 a, Semigroup b) => Semigroup (a, b)

Since: base-4.9.0.0

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 (Proxy s)

Since: base-4.9.0.0

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)

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 a, Semigroup b, Semigroup c) => Semigroup (a, b, c)

Since: base-4.9.0.0

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)

Alternative f => Semigroup (Alt f a)

Since: base-4.9.0.0

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 a, Semigroup b, Semigroup c, Semigroup d) => Semigroup (a, b, c, d)

Since: base-4.9.0.0

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 a, Semigroup b, Semigroup c, Semigroup d, Semigroup e) => Semigroup (a, b, c, d, e)

Since: base-4.9.0.0

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)

data Set a

A set of values a.

Instances

Foldable Set

Defined in Data.Set.Internal

Methods

fold :: Monoid m => Set m -> 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

Defined in Data.Set.Internal

Methods

liftEq :: (a -> b -> Bool) -> Set a -> Set b -> Bool

Ord1 Set

Since: containers-0.5.9

Defined in Data.Set.Internal

Methods

liftCompare :: (a -> b -> Ordering) -> Set a -> Set b -> Ordering

Show1 Set

Since: containers-0.5.9

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

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)

Defined in Data.Set.Internal

Methods

(==) :: Set a -> Set a -> Bool

(/=) :: Set a -> Set a -> Bool

(Data a, Ord a) => Data (Set a)

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 :: (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)

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)

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)

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

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)

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)

Defined in Data.Set.Internal

Methods

rnf :: Set a -> ()

type Item (Set a)

Defined in Data.Set.Internal

type Item (Set a) = a

unwords :: [Text] -> Text

O(n) Joins words using single space characters.

unlines :: [Text] -> Text

O(n) Joins lines, after appending a terminating newline to each.

lines :: Text -> [Text]

O(n) Breaks a Text up into a list of Texts at newline Chars. The resulting strings do not contain newlines.

words :: Text -> [Text]

O(n) Breaks a Text up into a list of words, delimited by Chars representing white space.

data Text

A space efficient, packed, unboxed Unicode text type.

Instances

type Item Text

Defined in Data.Text

type Item Text = Char

fst :: (a, b) -> a

Extract the first component of a pair.

snd :: (a, b) -> b

Extract the second component of a pair.

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

Swap the components of a pair.

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

uncurry converts a curried function to a function on pairs.

Examples

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

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

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

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

curry converts an uncurried function to a curried function.

Examples

>>> curry fst 1 2
1

trace :: String -> a -> a

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.

>>> let x = 123; f = show
>>> trace ("calling f with x = " ++ show x) (f x)
"calling f with x = 123
123"

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.

traceMarkerIO :: String -> IO ()

The traceMarkerIO function emits a marker to the eventlog, if eventlog profiling is available and enabled at runtime.

Compared to traceMarker, traceMarkerIO sequences the event with respect to other IO actions.

Since: base-4.7.0.0

traceMarker :: String -> a -> a

The traceMarker function emits a marker to the eventlog, if eventlog profiling is available and enabled at runtime. The String is the name of the marker. The name is just used in the profiling tools to help you keep clear which marker is which.

This function is suitable for use in pure code. In an IO context use traceMarkerIO instead.

Note that when using GHC's SMP runtime, it is possible (but rare) to get duplicate events emitted if two CPUs simultaneously evaluate the same thunk that uses traceMarker.

Since: base-4.7.0.0

traceEventIO :: String -> IO ()

The traceEventIO function emits a message to the eventlog, if eventlog profiling is available and enabled at runtime.

Compared to traceEvent, traceEventIO sequences the event with respect to other IO actions.

Since: base-4.5.0.0

traceEvent :: String -> a -> a

The traceEvent function behaves like trace with the difference that the message is emitted to the eventlog, if eventlog profiling is available and enabled at runtime.

It is suitable for use in pure code. In an IO context use traceEventIO instead.

Note that when using GHC's SMP runtime, it is possible (but rare) to get duplicate events emitted if two CPUs simultaneously evaluate the same thunk that uses traceEvent.

Since: base-4.5.0.0

traceStack :: String -> a -> a

like trace, but additionally prints a call stack if one is available.

In the current GHC implementation, the call stack is only available if the program was compiled with -prof; otherwise traceStack behaves exactly like trace. Entries in the call stack correspond to SCC annotations, so it is a good idea to use -fprof-auto or -fprof-auto-calls to add SCC annotations automatically.

Since: base-4.5.0.0

traceShowM :: (Show a, Applicative f) => a -> f ()

Like traceM, but uses show on the argument to convert it to a String.

>>> :{
do
    x <- Just 3
    traceShowM x
    y <- pure 12
    traceShowM y
    pure (x*2 + y)
:}
3
12
Just 18

Since: base-4.7.0.0

traceM :: Applicative f => String -> f ()

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 IO 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, liftIO . traceIO may be a better option.

>>> :{
do
    x <- Just 3
    traceM ("x: " ++ show x)
    y <- pure 12
    traceM ("y: " ++ show y)
    pure (x*2 + y)
:}
x: 3
y: 12
Just 18

Since: base-4.7.0.0

traceShowId :: Show a => a -> a

Like traceShow but returns the shown value instead of a third value.

>>> traceShowId (1+2+3, "hello" ++ "world")
(6,"helloworld")
(6,"helloworld")

Since: base-4.7.0.0

traceShow :: Show a => a -> b -> b

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 y:

>>> let f x y = traceShow (x,y) (x + y) in f (1+2) 5
(3,5)
8

traceId :: String -> String

Like trace but returns the message instead of a third value.

>>> traceId "hello"
"hello
hello"

Since: base-4.7.0.0

traceIO :: String -> IO ()

The traceIO function outputs the trace message from the IO monad. This sequences the output with respect to other IO actions.

Since: base-4.5.0.0

seq :: a -> b -> b

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.

type String = [Char]

A String is a list of characters. String constants in Haskell are values of type String.

($!) :: (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.

undefined :: HasCallStack => a

A special case of error. It is expected that compilers will recognize this and insert error messages which are more appropriate to the context in which undefined appears.

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

Eq Double

Defined in GHC.Classes

Methods

(==) :: Double -> Double -> Bool

(/=) :: Double -> Double -> Bool

Floating Double

Since: base-2.1

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

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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Double

readList :: ReadS [Double]

readPrec :: ReadPrec Double

readListPrec :: ReadPrec [Double]

RealFloat Double

Since: base-2.1

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 -> *)

Defined in GHC.Generics

Associated Types

type Rep1 (URec Double) :: k -> *

Methods

from1 :: URec Double a -> Rep1 (URec Double) a

to1 :: Rep1 (URec Double) a -> URec Double a

Functor (URec Double :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Double a -> URec Double b

(<$) :: a -> URec Double b -> URec Double a

Foldable (URec Double :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec Double m -> m

foldMap :: Monoid m => (a -> m) -> URec Double a -> m

foldr :: (a -> b -> b) -> b -> URec Double a -> b

foldr' :: (a -> b -> b) -> b -> URec Double a -> b

foldl :: (b -> a -> b) -> b -> URec Double a -> b

foldl' :: (b -> a -> b) -> b -> URec Double a -> b

foldr1 :: (a -> a -> a) -> URec Double a -> a

foldl1 :: (a -> a -> a) -> URec Double a -> a

toList :: URec Double a -> [a]

null :: URec Double a -> Bool

length :: URec Double a -> Int

elem :: Eq a => a -> URec Double a -> Bool

maximum :: Ord a => URec Double a -> a

minimum :: Ord a => URec Double a -> a

sum :: Num a => URec Double a -> a

product :: Num a => URec Double a -> a

Traversable (URec Double :: * -> *)

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> URec Double a -> f (URec Double b)

sequenceA :: Applicative f => URec Double (f a) -> f (URec Double a)

mapM :: Monad m => (a -> m b) -> URec Double a -> m (URec Double b)

sequence :: Monad m => URec Double (m a) -> m (URec Double a)

Eq (URec Double p)

Defined in GHC.Generics

Methods

(==) :: URec Double p -> URec Double p -> Bool

(/=) :: URec Double p -> URec Double p -> Bool

Ord (URec Double p)

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)

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)

Defined in GHC.Generics

Associated Types

type Rep (URec Double p) :: * -> *

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

Defined in GHC.Generics

data URec Double (p :: k) = UDouble {

• uDouble# :: Double#

}

type Rep1 (URec Double :: k -> *)

Defined in GHC.Generics

type Rep1 (URec Double :: k -> *) = D1 (MetaData "URec" "GHC.Generics" "base" False) (C1 (MetaCons "UDouble" PrefixI True) (S1 (MetaSel (Just "uDouble#") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (UDouble :: k -> *)))

type Rep (URec Double p)

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 :: * -> *)))

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

Eq Float

Defined in GHC.Classes

Methods

(==) :: Float -> Float -> Bool

(/=) :: Float -> Float -> Bool

Floating Float

Since: base-2.1

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

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

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Float

readList :: ReadS [Float]

readPrec :: ReadPrec Float

readListPrec :: ReadPrec [Float]

RealFloat Float

Since: base-2.1

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 -> *)

Defined in GHC.Generics

Associated Types

type Rep1 (URec Float) :: k -> *

Methods

from1 :: URec Float a -> Rep1 (URec Float) a

to1 :: Rep1 (URec Float) a -> URec Float a

Functor (URec Float :: * -> *)

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Float a -> URec Float b

(<$) :: a -> URec Float b -> URec Float a

Foldable (URec Float :: * -> *)

Defined in Data.Foldable

Methods

fold :: Monoid m => URec Float m -> m

foldMap :: Monoid m => (a -> m) -> URec Float a -> m

foldr :: (a -> b -> b) -> b -> URec Float a -> b

foldr' :: (a -> b -> b) -> b -> URec Float a -> b

foldl :: (b -> a -> b) -> b -> URec Float a -> b

foldl' :: (b -> a -> b) -> b -> URec Float a -> b

foldr1 :: (a -> a -> a) -> URec Float a -> a

foldl1 :: (a -> a -> a) -> URec Float a -> a

toList :: URec Float a -> [a]

null :: URec Float a -> Bool

length :: URec Float a -> Int

elem :: Eq a => a -> URec Float a -> Bool

maximum :: Ord a => URec Float a -> a

minimum :: Ord a => URec Float a -> a

sum :: Num a => URec Float a -> a

product :: Num a => URec Float a -> a

Traversable (URec Float :: * -> *)

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> URec Float a -> f (URec Float b)

sequenceA :: Applicative f => URec Float (f a) -> f (URec Float a)

mapM :: Monad m => (a -> m b) -> URec Float a -> m (URec Float b)

sequence :: Monad m => URec Float (m a) -> m (URec Float a)

Eq (URec Float p)

Defined in GHC.Generics

Methods

(==) :: URec Float p -> URec Float p -> Bool

(/=) :: URec Float p -> URec Float p -> Bool

Ord (URec Float p)

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)

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)

Defined in GHC.Generics

Associated Types

type Rep (URec Float p) :: * -> *

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

Defined in GHC.Generics

data URec Float (p :: k) = UFloat {

• uFloat# :: Float#

}

type Rep1 (URec Float :: k -> *)

Defined in GHC.Generics

type Rep1 (URec Float :: k -> *) = D1 (MetaData "URec" "GHC.Generics" "base" False) (C1 (MetaCons "UFloat" PrefixI True) (S1 (MetaSel (Just "uFloat#") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (UFloat :: k -> *)))

type Rep (URec Float p)

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 :: * -> *)))

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

Monad IO

Since: base-2.1

Defined in GHC.Base

Methods

(>>=) :: IO a -> (a -> IO b) -> IO b

(>>) :: IO a -> IO b -> IO b

return :: a -> IO a

fail :: String -> IO a

Functor IO

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> IO a -> IO b

(<$) :: a -> IO b -> IO a

Applicative IO

Since: base-2.1

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

Defined in Control.Monad.IO.Class

Methods

liftIO :: IO a -> IO a

Alternative IO

Since: base-4.9.0.0

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

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

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

Defined in GHC.Base

Methods

mempty :: IO a

mappend :: IO a -> IO a -> IO a

mconcat :: [IO a] -> IO a

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.

class Num a where

Basic numeric class.

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

Num Int

Since: base-2.1

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

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

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

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

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

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 Word

Since: base-2.1

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

Integral a => Num (Ratio a)

Since: base-2.0.1

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

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

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 (Sum a)

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)

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

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 (f a) => Num (Alt f a)

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

data Integer

Invariant: Jn# and Jp# are used iff value doesn't fit in S#

Useful properties resulting from the invariants:

• abs (S# _) <= abs (Jp# _)

• abs (S# _) <  abs (Jn# _)

Instances

Enum Integer

Since: base-2.1

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

Defined in GHC.Integer.Type

Methods

(==) :: Integer -> Integer -> Bool

(/=) :: Integer -> Integer -> Bool

Integral Integer

Since: base-2.0.1

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

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

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

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

Defined in GHC.Real

Methods

toRational :: Integer -> Rational

Show Integer

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Integer -> ShowS

show :: Integer -> String

showList :: [Integer] -> ShowS

Ix Integer

Since: base-2.1

Defined in GHC.Arr

Methods

range :: (Integer, Integer) -> [Integer]

index :: (Integer, Integer) -> Integer -> Int

unsafeIndex :: (Integer, Integer) -> Integer -> Int

inRange :: (Integer, Integer) -> Integer -> Bool

rangeSize :: (Integer, Integer) -> Int

unsafeRangeSize :: (Integer, Integer) -> Int

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.

fromIntegral :: (Integral a, Num b) => a -> b

general coercion from integral types

class Num a => Fractional a where

Fractional numbers, supporting real division.

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

Integral a => Fractional (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

(/) :: Ratio a -> Ratio a -> Ratio a

recip :: Ratio a -> Ratio a

fromRational :: Rational -> Ratio a

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

Integral numbers, supporting integer division.

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

Integral Int

Since: base-2.0.1

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

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

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

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

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

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 Word

Since: base-2.1

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

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

Integral a => RealFrac (Ratio a)

Since: base-2.0.1

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

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

raise a number to an integral power

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

raise a number to a non-negative integral power

class Show a where

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

Methods

show :: a -> String

A specialised variant of showsPrec, using precedence context zero, and returning an ordinary String.

Instances

Show Bool

Defined in GHC.Show

Methods

showsPrec :: Int -> Bool -> ShowS

show :: Bool -> String

showList :: [Bool] -> ShowS

Show Char

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Char -> ShowS

show :: Char -> String

showList :: [Char] -> ShowS

Show Int

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Int -> ShowS

show :: Int -> String

showList :: [Int] -> ShowS

Show Int8

Since: base-2.1

Defined in GHC.Int

Methods

showsPrec :: Int -> Int8 -> ShowS

show :: Int8 -> String

showList :: [Int8] -> ShowS

Show Int16

Since: base-2.1

Defined in GHC.Int

Methods

showsPrec :: Int -> Int16 -> ShowS

show :: Int16 -> String

showList :: [Int16] -> ShowS

Show Int32

Since: base-2.1

Defined in GHC.Int

Methods

showsPrec :: Int -> Int32 -> ShowS

show :: Int32 -> String

showList :: [Int32] -> ShowS

Show Int64

Since: base-2.1

Defined in GHC.Int

Methods

showsPrec :: Int -> Int64 -> ShowS

show :: Int64 -> String

showList :: [Int64] -> ShowS

Show Integer

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Integer -> ShowS

show :: Integer -> String

showList :: [Integer] -> ShowS

Show Ordering

Defined in GHC.Show

Methods

showsPrec :: Int -> Ordering -> ShowS

show :: Ordering -> String

showList :: [Ordering] -> ShowS

Show Word

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Word -> ShowS

show :: Word -> String

showList :: [Word] -> ShowS

Show RuntimeRep

Defined in GHC.Show

Methods

showsPrec :: Int -> RuntimeRep -> ShowS

show :: RuntimeRep -> String

showList :: [RuntimeRep] -> ShowS

Show VecCount

Defined in GHC.Show

Methods

showsPrec :: Int -> VecCount -> ShowS

show :: VecCount -> String

showList :: [VecCount] -> ShowS

Show VecElem

Defined in GHC.Show

Methods

showsPrec :: Int -> VecElem -> ShowS

show :: VecElem -> String

showList :: [VecElem] -> ShowS

Show CallStack

Since: base-4.9.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> CallStack -> ShowS

show :: CallStack -> String

showList :: [CallStack] -> ShowS

Show ()

Defined in GHC.Show

Methods

showsPrec :: Int -> () -> ShowS

show :: () -> String

showList :: [()] -> ShowS

Show TyCon

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> TyCon -> ShowS

show :: TyCon -> String

showList :: [TyCon] -> ShowS

Show Module

Since: base-4.9.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Module -> ShowS

show :: Module -> String

showList :: [Module] -> ShowS

Show TrName

Since: base-4.9.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> TrName -> ShowS

show :: TrName -> String

showList :: [TrName] -> ShowS

Show KindRep

Defined in GHC.Show

Methods

showsPrec :: Int -> KindRep -> ShowS

show :: KindRep -> String

showList :: [KindRep] -> ShowS

Show TypeLitSort

Defined in GHC.Show

Methods

showsPrec :: Int -> TypeLitSort -> ShowS

show :: TypeLitSort -> String

showList :: [TypeLitSort] -> ShowS

Show Handle

Since: base-4.1.0.0

Defined in GHC.IO.Handle.Types

Methods

showsPrec :: Int -> Handle -> ShowS

show :: Handle -> String

showList :: [Handle] -> ShowS

Show HandleType

Since: base-4.1.0.0

Defined in GHC.IO.Handle.Types

Methods

showsPrec :: Int -> HandleType -> ShowS

show :: HandleType -> String

showList :: [HandleType] -> ShowS

Show HandlePosn

Since: base-4.1.0.0

Defined in GHC.IO.Handle

Methods

showsPrec :: Int -> HandlePosn -> ShowS

show :: HandlePosn -> String

showList :: [HandlePosn] -> ShowS

Show BlockedIndefinitelyOnMVar

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> BlockedIndefinitelyOnMVar -> ShowS

show :: BlockedIndefinitelyOnMVar -> String

showList :: [BlockedIndefinitelyOnMVar] -> ShowS

Show BlockedIndefinitelyOnSTM

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> BlockedIndefinitelyOnSTM -> ShowS

show :: BlockedIndefinitelyOnSTM -> String

showList :: [BlockedIndefinitelyOnSTM] -> ShowS

Show Deadlock

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> Deadlock -> ShowS

show :: Deadlock -> String

showList :: [Deadlock] -> ShowS

Show AllocationLimitExceeded

Since: base-4.7.1.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> AllocationLimitExceeded -> ShowS

show :: AllocationLimitExceeded -> String

showList :: [AllocationLimitExceeded] -> ShowS

Show CompactionFailed

Since: base-4.10.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> CompactionFailed -> ShowS

show :: CompactionFailed -> String

showList :: [CompactionFailed] -> ShowS

Show AssertionFailed

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> AssertionFailed -> ShowS

show :: AssertionFailed -> String

showList :: [AssertionFailed] -> ShowS

Show SomeAsyncException

Since: base-4.7.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> SomeAsyncException -> ShowS

show :: SomeAsyncException -> String

showList :: [SomeAsyncException] -> ShowS

Show AsyncException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> AsyncException -> ShowS

show :: AsyncException -> String

showList :: [AsyncException] -> ShowS

Show ArrayException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> ArrayException -> ShowS

show :: ArrayException -> String

showList :: [ArrayException] -> ShowS

Show FixIOException

Since: base-4.11.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> FixIOException -> ShowS

show :: FixIOException -> String

showList :: [FixIOException] -> ShowS

Show ExitCode

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> ExitCode -> ShowS

show :: ExitCode -> String

showList :: [ExitCode] -> ShowS

Show IOErrorType

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> IOErrorType -> ShowS

show :: IOErrorType -> String

showList :: [IOErrorType] -> ShowS

Show BufferMode

Defined in GHC.IO.Handle.Types

Methods

showsPrec :: Int -> BufferMode -> ShowS

show :: BufferMode -> String

showList :: [BufferMode] -> ShowS

Show Newline

Defined in GHC.IO.Handle.Types

Methods

showsPrec :: Int -> Newline -> ShowS

show :: Newline -> String

showList :: [Newline] -> ShowS

Show NewlineMode

Defined in GHC.IO.Handle.Types

Methods

showsPrec :: Int -> NewlineMode -> ShowS

show :: NewlineMode -> String

showList :: [NewlineMode] -> ShowS

Show MaskingState

Defined in GHC.IO

Methods

showsPrec :: Int -> MaskingState -> ShowS

show :: MaskingState -> String

showList :: [MaskingState] -> ShowS

Show IOException

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> IOException -> ShowS

show :: IOException -> String

showList :: [IOException] -> ShowS

Show All

Defined in Data.Semigroup.Internal

Methods

showsPrec :: Int -> All -> ShowS

show :: All -> String

showList :: [All] -> ShowS

Show Any

Defined in Data.Semigroup.Internal

Methods

showsPrec :: Int -> Any -> ShowS

show :: Any -> String

showList :: [Any] -> ShowS

Show Fixity

Defined in GHC.Generics

Methods

showsPrec :: Int -> Fixity -> ShowS

show :: Fixity -> String

showList :: [Fixity] -> ShowS

Show Associativity

Defined in GHC.Generics

Methods

showsPrec :: Int -> Associativity -> ShowS

show :: Associativity -> String

showList :: [Associativity] -> ShowS

Show SourceUnpackedness

Defined in GHC.Generics

Methods

showsPrec :: Int -> SourceUnpackedness -> ShowS

show :: SourceUnpackedness -> String

showList :: [SourceUnpackedness] -> ShowS

Show SourceStrictness

Defined in GHC.Generics

Methods

showsPrec :: Int -> SourceStrictness -> ShowS

show :: SourceStrictness -> String

showList :: [SourceStrictness] -> ShowS

Show DecidedStrictness

Defined in GHC.Generics

Methods

showsPrec :: Int -> DecidedStrictness -> ShowS

show :: DecidedStrictness -> String

showList :: [DecidedStrictness] -> ShowS

Show SrcLoc

Defined in GHC.Show

Methods

showsPrec :: Int -> SrcLoc -> ShowS

show :: SrcLoc -> String

showList :: [SrcLoc] -> ShowS

Show IntSet

Defined in Data.IntSet.Internal

Methods

showsPrec :: Int -> IntSet -> ShowS

show :: IntSet -> String

showList :: [IntSet] -> ShowS

Show ZonedTime

Defined in Data.Time.LocalTime.Internal.ZonedTime

Methods

showsPrec :: Int -> ZonedTime -> ShowS

show :: ZonedTime -> String

showList :: [ZonedTime] -> ShowS

Show LocalTime

Defined in Data.Time.LocalTime.Internal.LocalTime

Methods

showsPrec :: Int -> LocalTime -> ShowS

show :: LocalTime -> String

showList :: [LocalTime] -> ShowS

Show DateFormatSpec

Defined in Data.Time.Format.Parse

Methods

showsPrec :: Int -> DateFormatSpec -> ShowS

show :: DateFormatSpec -> String

showList :: [DateFormatSpec] -> ShowS

Show Padding

Defined in Data.Time.Format.Parse

Methods

showsPrec :: Int -> Padding -> ShowS

show :: Padding -> String

showList :: [Padding] -> ShowS

Show a => Show [a]

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> [a] -> ShowS

show :: [a] -> String

showList :: [[a]] -> ShowS

Show a => Show (Maybe a)

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

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

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

Defined in GHC.Ptr

Methods

showsPrec :: Int -> FunPtr a -> ShowS

show :: FunPtr a -> String

showList :: [FunPtr a] -> ShowS

Show p => Show (Par1 p)

Defined in GHC.Generics

Methods

showsPrec :: Int -> Par1 p -> ShowS

show :: Par1 p -> String

showList :: [Par1 p] -> ShowS

Show a => Show (Min a)

Defined in Data.Semigroup

Methods

showsPrec :: Int -> Min a -> ShowS

show :: Min a -> String

showList :: [Min a] -> ShowS

Show a => Show (Max a)

Defined in Data.Semigroup

Methods

showsPrec :: Int -> Max a -> ShowS

show :: Max a -> String

showList :: [Max a] -> ShowS

Show a => Show (First a)

Defined in Data.Semigroup

Methods

showsPrec :: Int -> First a -> ShowS

show :: First a -> String

showList :: [First a] -> ShowS

Show a => Show (Last a)

Defined in Data.Semigroup

Methods

showsPrec :: Int -> Last a -> ShowS

show :: Last a -> String

showList :: [Last a] -> ShowS

Show m => Show (WrappedMonoid m)

Defined in Data.Semigroup

Methods

showsPrec :: Int -> WrappedMonoid m -> ShowS

show :: WrappedMonoid m -> String

showList :: [WrappedMonoid m] -> ShowS

Show a => Show (Option a)

Defined in Data.Semigroup

Methods

showsPrec :: Int -> Option a -> ShowS

show :: Option a -> String

showList :: [Option a] -> ShowS

Show a => Show (ZipList a)

Defined in Control.Applicative

Methods

showsPrec :: Int -> ZipList a -> ShowS

show :: ZipList a -> String

showList :: [ZipList a] -> ShowS

Show a => Show (First a)

Defined in Data.Monoid

Methods

showsPrec :: Int -> First a -> ShowS

show :: First a -> String

showList :: [First a] -> ShowS

Show a => Show (Last a)

Defined in Data.Monoid

Methods

showsPrec :: Int -> Last a -> ShowS

show :: Last a -> String

showList :: [Last a] -> ShowS

Show a => Show (Dual a)

Defined in Data.Semigroup.Internal

Methods

showsPrec :: Int -> Dual a -> ShowS

show :: Dual a -> String

showList :: [Dual a] -> ShowS

Show a => Show (Sum a)

Defined in Data.Semigroup.Internal

Methods

showsPrec :: Int -> Sum a -> ShowS

show :: Sum a -> String

showList :: [Sum a] -> ShowS

Show a => Show (Product a)

Defined in Data.Semigroup.Internal

Methods

showsPrec :: Int -> Product a -> ShowS

show :: Product a -> String

showList :: [Product a] -> ShowS

Show a => Show (Down a)

Since: base-4.7.0.0

Defined in Data.Ord

Methods

showsPrec :: Int -> Down a -> ShowS

show :: Down a -> String

showList :: [Down a] -> ShowS

Show a => Show (NonEmpty a)

Defined in GHC.Show

Methods

showsPrec :: Int -> NonEmpty a -> ShowS

show :: NonEmpty a -> String

showList :: [NonEmpty a] -> ShowS

Show a => Show (Set a)

Defined in Data.Set.Internal

Methods

showsPrec :: Int -> Set a -> ShowS

show :: Set a -> String

showList :: [Set a] -> ShowS

(Show a, Show b) => Show (Either a b)

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

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

Defined in GHC.Generics

Methods

showsPrec :: Int -> U1 p -> ShowS

show :: U1 p -> String

showList :: [U1 p] -> ShowS

(Show a, Show b) => Show (a, b)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b) -> ShowS

show :: (a, b) -> String

showList :: [(a, b)] -> ShowS

(Ix a, Show a, Show b) => Show (Array a b)

Since: base-2.1

Defined in GHC.Arr

Methods

showsPrec :: Int -> Array a b -> ShowS

show :: Array a b -> String

showList :: [Array a b] -> ShowS

(Show a, Show b) => Show (Arg a b)

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

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)

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)

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)

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)

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)

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)

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)

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

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c) -> ShowS

show :: (a, b, c) -> String

showList :: [(a, b, c)] -> ShowS

Show (f a) => Show (Alt f a)

Defined in Data.Semigroup.Internal

Methods

showsPrec :: Int -> Alt f a -> ShowS

show :: Alt f a -> String

showList :: [Alt f a] -> ShowS

Show (a :~: b)

Defined in Data.Type.Equality

Methods

showsPrec :: Int -> (a :~: b) -> ShowS

show :: (a :~: b) -> String

showList :: [a :~: b] -> ShowS

(Show e, Show1 m, Show a) => Show (ErrorT e m a)

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)

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)

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)

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

Defined in GHC.Show

Methods

showsPrec :: Int -> (a, b, c, d) -> ShowS

show :: (a, b, c, d) -> String

showList :: [(a, b, c, d)] -> ShowS

Show (a :~~: b)

Since: base-4.10.0.0

Defined in Data.Type.Equality

Methods

showsPrec :: Int -> (a :~~: b) -> ShowS

show :: (a :~~: b) -> String

showList :: [a :~~: b] -> ShowS

Show (f p) => Show (M1 i c f p)

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)

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

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

(Show a, Show b, Show c, Show d, Show e, Show f) => Show (a, b, c, d, e, f)

Since: base-2.1

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

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

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

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

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

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

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

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

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

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 Fractional a => Floating a where

Trigonometric and hyperbolic functions and related functions.

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

Floating Double

Since: base-2.1

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

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

ioError :: IOError -> IO a

Raise an IOError in the IO monad.

userError :: String -> IOError

Construct an IOError value with a string describing the error. The fail method of the IO instance of the Monad class raises a userError, thus:

instance Monad IO where
  ...
  fail s = ioError (userError s)

type IOError = IOException

The Haskell 2010 type for exceptions in the IO monad. Any I/O operation may raise an IOError instead of returning a result. For a more general type of exception, including also those that arise in pure code, see Exception.

In Haskell 2010, this is an opaque type.

read :: Read a => String -> a

The read function reads input from a string, which must be completely consumed by the input process. read fails with an error if the parse is unsuccessful, and it is therefore discouraged from being used in real applications. Use readMaybe or readEither for safe alternatives.

>>> read "123" :: Int
123

>>> read "hello" :: Int
*** Exception: Prelude.read: no parse