Incipit.Base

Reexports from base.

Documentation

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

A functor with application, providing operations to

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

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

(<*>) = liftA2 id

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

Further, any definition must satisfy the following:

Identity

pure id <*> v = v

Composition

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

Homomorphism

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

Interchange

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

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

• u *> v = (id <$ u) <*> v

• u <* v = liftA2 const u v

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

• fmap f x = pure f <*> x

It may be useful to note that supposing

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

it follows from the above that

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

If f is also a Monad, it should satisfy

• pure = return

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

• (*>) = (>>)

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

Minimal complete definition

pure, ((<*>) | liftA2)

Methods

pure :: a -> f a

Lift a value.

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

Sequential application.

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

Example

Used in combination with (<$>), (<*>) can be used to build a record.

>>> data MyState = MyState {arg1 :: Foo, arg2 :: Bar, arg3 :: Baz}

>>> produceFoo :: Applicative f => f Foo

>>> produceBar :: Applicative f => f Bar
>>> produceBaz :: Applicative f => f Baz

>>> mkState :: Applicative f => f MyState
>>> mkState = MyState <$> produceFoo <*> produceBar <*> produceBaz

liftA2 :: (a -> b -> c) -> f a -> f b -> f c

Lift a binary function to actions.

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

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

Example

>>> liftA2 (,) (Just 3) (Just 5)
Just (3,5)

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

Sequence actions, discarding the value of the first argument.

Examples

If used in conjunction with the Applicative instance for Maybe, you can chain Maybe computations, with a possible "early return" in case of Nothing.

>>> Just 2 *> Just 3
Just 3

>>> Nothing *> Just 3
Nothing

Of course a more interesting use case would be to have effectful computations instead of just returning pure values.

>>> import Data.Char
>>> import Text.ParserCombinators.ReadP
>>> let p = string "my name is " *> munch1 isAlpha <* eof
>>> readP_to_S p "my name is Simon"
[("Simon","")]

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

Sequence actions, discarding the value of the second argument.

Instances

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 Complex

Since: base-4.9.0.0

Defined in Data.Complex

Methods

pure :: a -> Complex a

(<*>) :: Complex (a -> b) -> Complex a -> Complex b

liftA2 :: (a -> b -> c) -> Complex a -> Complex b -> Complex c

(*>) :: Complex a -> Complex b -> Complex b

(<*) :: Complex a -> Complex b -> Complex a

Applicative Identity

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

pure :: a -> Identity a

(<*>) :: Identity (a -> b) -> Identity a -> Identity b

liftA2 :: (a -> b -> c) -> Identity a -> Identity b -> Identity c

(*>) :: Identity a -> Identity b -> Identity b

(<*) :: Identity a -> Identity b -> Identity a

Applicative First

Since: base-4.8.0.0

Defined in Data.Monoid

Methods

pure :: a -> First a

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

liftA2 :: (a -> b -> c) -> First a -> First b -> First c

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

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

Applicative Last

Since: base-4.8.0.0

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 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 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 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 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 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 P

Since: base-4.5.0.0

Defined in Text.ParserCombinators.ReadP

Methods

pure :: a -> P a

(<*>) :: P (a -> b) -> P a -> P b

liftA2 :: (a -> b -> c) -> P a -> P b -> P c

(*>) :: P a -> P b -> P b

(<*) :: P a -> P b -> P a

Applicative ReadP

Since: base-4.6.0.0

Defined in Text.ParserCombinators.ReadP

Methods

pure :: a -> ReadP a

(<*>) :: ReadP (a -> b) -> ReadP a -> ReadP b

liftA2 :: (a -> b -> c) -> ReadP a -> ReadP b -> ReadP c

(*>) :: ReadP a -> ReadP b -> ReadP b

(<*) :: ReadP a -> ReadP b -> ReadP a

Applicative Seq

Since: containers-0.5.4

Defined in Data.Sequence.Internal

Methods

pure :: a -> Seq a

(<*>) :: Seq (a -> b) -> Seq a -> Seq b

liftA2 :: (a -> b -> c) -> Seq a -> Seq b -> Seq c

(*>) :: Seq a -> Seq b -> Seq b

(<*) :: Seq a -> Seq b -> Seq a

Applicative DList

Defined in Data.DList.Internal

Methods

pure :: a -> DList a

(<*>) :: DList (a -> b) -> DList a -> DList b

liftA2 :: (a -> b -> c) -> DList a -> DList b -> DList c

(*>) :: DList a -> DList b -> DList b

(<*) :: DList a -> DList b -> DList 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 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 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 Solo

Since: base-4.15

Defined in GHC.Base

Methods

pure :: a -> Solo a

(<*>) :: Solo (a -> b) -> Solo a -> Solo b

liftA2 :: (a -> b -> c) -> Solo a -> Solo b -> Solo c

(*>) :: Solo a -> Solo b -> Solo b

(<*) :: Solo a -> Solo b -> Solo a

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]

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 (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 (Proxy :: Type -> Type)

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 (U1 :: Type -> Type)

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)

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 m => Applicative (Kleisli m a)

Since: base-4.14.0.0

Defined in Control.Arrow

Methods

pure :: a0 -> Kleisli m a a0

(<*>) :: Kleisli m a (a0 -> b) -> Kleisli m a a0 -> Kleisli m a b

liftA2 :: (a0 -> b -> c) -> Kleisli m a a0 -> Kleisli m a b -> Kleisli m a c

(*>) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a b

(<*) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a a0

Monoid m => Applicative (Const m :: Type -> Type)

Since: base-2.0.1

Defined in Data.Functor.Const

Methods

pure :: a -> Const m a

(<*>) :: Const m (a -> b) -> Const m a -> Const m b

liftA2 :: (a -> b -> c) -> Const m a -> Const m b -> Const m c

(*>) :: Const m a -> Const m b -> Const m b

(<*) :: Const m a -> Const m b -> Const m a

Applicative f => Applicative (Ap f)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

pure :: a -> Ap f a

(<*>) :: Ap f (a -> b) -> Ap f a -> Ap f b

liftA2 :: (a -> b -> c) -> Ap f a -> Ap f b -> Ap f c

(*>) :: Ap f a -> Ap f b -> Ap f b

(<*) :: Ap f a -> Ap f b -> Ap f a

(Generic1 f, Applicative (Rep1 f)) => Applicative (Generically1 f)

Since: base-4.17.0.0

Defined in GHC.Generics

Methods

pure :: a -> Generically1 f a

(<*>) :: Generically1 f (a -> b) -> Generically1 f a -> Generically1 f b

liftA2 :: (a -> b -> c) -> Generically1 f a -> Generically1 f b -> Generically1 f c

(*>) :: Generically1 f a -> Generically1 f b -> Generically1 f b

(<*) :: Generically1 f a -> Generically1 f b -> Generically1 f 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

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

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

Since: containers-0.5.9

Defined in Data.IntMap.Internal

Methods

pure :: a -> WhenMissing f x a

(<*>) :: WhenMissing f x (a -> b) -> WhenMissing f x a -> WhenMissing f x b

liftA2 :: (a -> b -> c) -> WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x c

(*>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b

(<*) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x a

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

Since: base-4.14.0.0

Defined in GHC.Base

Methods

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

(<*>) :: (a, b, a0 -> b0) -> (a, b, a0) -> (a, b, b0)

liftA2 :: (a0 -> b0 -> c) -> (a, b, a0) -> (a, b, b0) -> (a, b, c)

(*>) :: (a, b, a0) -> (a, b, b0) -> (a, b, b0)

(<*) :: (a, b, a0) -> (a, b, b0) -> (a, b, a0)

(Applicative f, Applicative g) => Applicative (Product f g)

Since: base-4.9.0.0

Defined in Data.Functor.Product

Methods

pure :: a -> Product f g a

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

liftA2 :: (a -> b -> c) -> Product f g a -> Product f g b -> Product f g c

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

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

(Applicative f, 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

Monoid c => Applicative (K1 i c :: Type -> Type)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

pure :: a -> K1 i c a

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

liftA2 :: (a -> b -> c0) -> K1 i c a -> K1 i c b -> K1 i c c0

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

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

(Monad f, Applicative f) => Applicative (WhenMatched f x y)

Equivalent to ReaderT Key (ReaderT x (ReaderT y (MaybeT f)))

Since: containers-0.5.9

Defined in Data.IntMap.Internal

Methods

pure :: a -> WhenMatched f x y a

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

liftA2 :: (a -> b -> c) -> WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y c

(*>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b

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

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

Since: base-4.14.0.0

Defined in GHC.Base

Methods

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

(<*>) :: (a, b, c, a0 -> b0) -> (a, b, c, a0) -> (a, b, c, b0)

liftA2 :: (a0 -> b0 -> c0) -> (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, c0)

(*>) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, b0)

(<*) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, a0)

Applicative ((->) r)

Since: base-2.1

Defined in GHC.Base

Methods

pure :: a -> r -> a

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

liftA2 :: (a -> b -> c) -> (r -> a) -> (r -> b) -> r -> c

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

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

(Applicative f, Applicative g) => Applicative (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

pure :: a -> Compose f g a

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

liftA2 :: (a -> b -> c) -> Compose f g a -> Compose f g b -> Compose f g c

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

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

(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 => 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

(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 :: Type -> Type) where

A monoid on applicative functors.

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

• some v = (:) <$> v <*> many v

• many v = some v <|> pure []

Minimal complete definition

empty, (<|>)

Methods

empty :: f a

The identity of <|>

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

An associative binary operation

some :: f a -> f [a]

One or more.

many :: f a -> f [a]

Zero or more.

Instances

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 P

Since: base-4.5.0.0

Defined in Text.ParserCombinators.ReadP

Methods

empty :: P a

(<|>) :: P a -> P a -> P a

some :: P a -> P [a]

many :: P a -> P [a]

Alternative ReadP

Since: base-4.6.0.0

Defined in Text.ParserCombinators.ReadP

Methods

empty :: ReadP a

(<|>) :: ReadP a -> ReadP a -> ReadP a

some :: ReadP a -> ReadP [a]

many :: ReadP a -> ReadP [a]

Alternative Seq

Since: containers-0.5.4

Defined in Data.Sequence.Internal

Methods

empty :: Seq a

(<|>) :: Seq a -> Seq a -> Seq a

some :: Seq a -> Seq [a]

many :: Seq a -> Seq [a]

Alternative DList

Defined in Data.DList.Internal

Methods

empty :: DList a

(<|>) :: DList a -> DList a -> DList a

some :: DList a -> DList [a]

many :: DList a -> DList [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 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 []

Since: base-2.1

Defined in GHC.Base

Methods

empty :: [a]

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

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

many :: [a] -> [[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 :: Type -> Type)

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 (U1 :: Type -> Type)

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]

(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 m => Alternative (Kleisli m a)

Since: base-4.14.0.0

Defined in Control.Arrow

Methods

empty :: Kleisli m a a0

(<|>) :: Kleisli m a a0 -> Kleisli m a a0 -> Kleisli m a a0

some :: Kleisli m a a0 -> Kleisli m a [a0]

many :: Kleisli m a a0 -> Kleisli m a [a0]

Alternative f => Alternative (Ap f)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

empty :: Ap f a

(<|>) :: Ap f a -> Ap f a -> Ap f a

some :: Ap f a -> Ap f [a]

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

(Generic1 f, Alternative (Rep1 f)) => Alternative (Generically1 f)

Since: base-4.17.0.0

Defined in GHC.Generics

Methods

empty :: Generically1 f a

(<|>) :: Generically1 f a -> Generically1 f a -> Generically1 f a

some :: Generically1 f a -> Generically1 f [a]

many :: Generically1 f a -> Generically1 f [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]

(Alternative f, Alternative g) => Alternative (Product f g)

Since: base-4.9.0.0

Defined in Data.Functor.Product

Methods

empty :: Product f g a

(<|>) :: Product f g a -> Product f g a -> Product f g a

some :: Product f g a -> Product f g [a]

many :: Product f g a -> Product f g [a]

(Alternative f, Alternative 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, Applicative g) => Alternative (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

empty :: Compose f g a

(<|>) :: Compose f g a -> Compose f g a -> Compose f g a

some :: Compose f g a -> Compose f g [a]

many :: Compose f g a -> Compose f g [a]

(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]

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]

newtype Const a (b :: k)

The Const functor.

Constructors

Const

Fields

• getConst :: a

Instances

Generic1 (Const a :: k -> Type)

Defined in Data.Functor.Const

Associated Types

type Rep1 (Const a) :: k -> Type

Methods

from1 :: forall (a0 :: k0). Const a a0 -> Rep1 (Const a) a0

to1 :: forall (a0 :: k0). Rep1 (Const a) a0 -> Const a a0

Bifunctor (Const :: Type -> Type -> Type)

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

Foldable (Const m :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Functor.Const

Methods

fold :: Monoid m0 => Const m m0 -> m0

foldMap :: Monoid m0 => (a -> m0) -> Const m a -> m0

foldMap' :: Monoid m0 => (a -> m0) -> Const m a -> m0

foldr :: (a -> b -> b) -> b -> Const m a -> b

foldr' :: (a -> b -> b) -> b -> Const m a -> b

foldl :: (b -> a -> b) -> b -> Const m a -> b

foldl' :: (b -> a -> b) -> b -> Const m a -> b

foldr1 :: (a -> a -> a) -> Const m a -> a

foldl1 :: (a -> a -> a) -> Const m a -> a

toList :: Const m a -> [a]

null :: Const m a -> Bool

length :: Const m a -> Int

elem :: Eq a => a -> Const m a -> Bool

maximum :: Ord a => Const m a -> a

minimum :: Ord a => Const m a -> a

sum :: Num a => Const m a -> a

product :: Num a => Const m a -> a

Contravariant (Const a :: Type -> Type)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a0) -> Const a a0 -> Const a a'

(>$) :: b -> Const a b -> Const a a0

Traversable (Const m :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Const m a -> f (Const m b)

sequenceA :: Applicative f => Const m (f a) -> f (Const m a)

mapM :: Monad m0 => (a -> m0 b) -> Const m a -> m0 (Const m b)

sequence :: Monad m0 => Const m (m0 a) -> m0 (Const m a)

Monoid m => Applicative (Const m :: Type -> Type)

Since: base-2.0.1

Defined in Data.Functor.Const

Methods

pure :: a -> Const m a

(<*>) :: Const m (a -> b) -> Const m a -> Const m b

liftA2 :: (a -> b -> c) -> Const m a -> Const m b -> Const m c

(*>) :: Const m a -> Const m b -> Const m b

(<*) :: Const m a -> Const m b -> Const m a

Functor (Const m :: Type -> Type)

Since: base-2.1

Defined in Data.Functor.Const

Methods

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

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

IsString a => IsString (Const a b)

Since: base-4.9.0.0

Defined in Data.String

Methods

fromString :: String -> Const a b

Storable a => Storable (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

sizeOf :: Const a b -> Int

alignment :: Const a b -> Int

peekElemOff :: Ptr (Const a b) -> Int -> IO (Const a b)

pokeElemOff :: Ptr (Const a b) -> Int -> Const a b -> IO ()

peekByteOff :: Ptr b0 -> Int -> IO (Const a b)

pokeByteOff :: Ptr b0 -> Int -> Const a b -> IO ()

peek :: Ptr (Const a b) -> IO (Const a b)

poke :: Ptr (Const a b) -> Const a b -> IO ()

Monoid a => Monoid (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

mempty :: Const a b

mappend :: Const a b -> Const a b -> Const a b

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

Semigroup a => Semigroup (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

(<>) :: Const a b -> Const a b -> Const a b

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

stimes :: Integral b0 => b0 -> Const a b -> Const a b

Bits a => Bits (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

(.&.) :: Const a b -> Const a b -> Const a b

(.|.) :: Const a b -> Const a b -> Const a b

xor :: Const a b -> Const a b -> Const a b

complement :: Const a b -> Const a b

shift :: Const a b -> Int -> Const a b

rotate :: Const a b -> Int -> Const a b

zeroBits :: Const a b

bit :: Int -> Const a b

setBit :: Const a b -> Int -> Const a b

clearBit :: Const a b -> Int -> Const a b

complementBit :: Const a b -> Int -> Const a b

testBit :: Const a b -> Int -> Bool

bitSizeMaybe :: Const a b -> Maybe Int

bitSize :: Const a b -> Int

isSigned :: Const a b -> Bool

shiftL :: Const a b -> Int -> Const a b

unsafeShiftL :: Const a b -> Int -> Const a b

shiftR :: Const a b -> Int -> Const a b

unsafeShiftR :: Const a b -> Int -> Const a b

rotateL :: Const a b -> Int -> Const a b

rotateR :: Const a b -> Int -> Const a b

popCount :: Const a b -> Int

FiniteBits a => FiniteBits (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

finiteBitSize :: Const a b -> Int

countLeadingZeros :: Const a b -> Int

countTrailingZeros :: Const a b -> Int

Bounded a => Bounded (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

minBound :: Const a b

maxBound :: Const a b

Enum a => Enum (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

succ :: Const a b -> Const a b

pred :: Const a b -> Const a b

toEnum :: Int -> Const a b

fromEnum :: Const a b -> Int

enumFrom :: Const a b -> [Const a b]

enumFromThen :: Const a b -> Const a b -> [Const a b]

enumFromTo :: Const a b -> Const a b -> [Const a b]

enumFromThenTo :: Const a b -> Const a b -> Const a b -> [Const a b]

Floating a => Floating (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

pi :: Const a b

exp :: Const a b -> Const a b

log :: Const a b -> Const a b

sqrt :: Const a b -> Const a b

(**) :: Const a b -> Const a b -> Const a b

logBase :: Const a b -> Const a b -> Const a b

sin :: Const a b -> Const a b

cos :: Const a b -> Const a b

tan :: Const a b -> Const a b

asin :: Const a b -> Const a b

acos :: Const a b -> Const a b

atan :: Const a b -> Const a b

sinh :: Const a b -> Const a b

cosh :: Const a b -> Const a b

tanh :: Const a b -> Const a b

asinh :: Const a b -> Const a b

acosh :: Const a b -> Const a b

atanh :: Const a b -> Const a b

log1p :: Const a b -> Const a b

expm1 :: Const a b -> Const a b

log1pexp :: Const a b -> Const a b

log1mexp :: Const a b -> Const a b

RealFloat a => RealFloat (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

floatRadix :: Const a b -> Integer

floatDigits :: Const a b -> Int

floatRange :: Const a b -> (Int, Int)

decodeFloat :: Const a b -> (Integer, Int)

encodeFloat :: Integer -> Int -> Const a b

exponent :: Const a b -> Int

significand :: Const a b -> Const a b

scaleFloat :: Int -> Const a b -> Const a b

isNaN :: Const a b -> Bool

isInfinite :: Const a b -> Bool

isDenormalized :: Const a b -> Bool

isNegativeZero :: Const a b -> Bool

isIEEE :: Const a b -> Bool

atan2 :: Const a b -> Const a b -> Const a b

Generic (Const a b)

Defined in Data.Functor.Const

Associated Types

type Rep (Const a b) :: Type -> Type

Methods

from :: Const a b -> Rep (Const a b) x

to :: Rep (Const a b) x -> Const a b

Ix a => Ix (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

range :: (Const a b, Const a b) -> [Const a b]

index :: (Const a b, Const a b) -> Const a b -> Int

unsafeIndex :: (Const a b, Const a b) -> Const a b -> Int

inRange :: (Const a b, Const a b) -> Const a b -> Bool

rangeSize :: (Const a b, Const a b) -> Int

unsafeRangeSize :: (Const a b, Const a b) -> Int

Num a => Num (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

(+) :: Const a b -> Const a b -> Const a b

(-) :: Const a b -> Const a b -> Const a b

(*) :: Const a b -> Const a b -> Const a b

negate :: Const a b -> Const a b

abs :: Const a b -> Const a b

signum :: Const a b -> Const a b

fromInteger :: Integer -> Const a b

Read a => Read (Const a b)

This instance would be equivalent to the derived instances of the Const newtype if the getConst field were removed

Since: base-4.8.0.0

Defined in Data.Functor.Const

Methods

readsPrec :: Int -> ReadS (Const a b)

readList :: ReadS [Const a b]

readPrec :: ReadPrec (Const a b)

readListPrec :: ReadPrec [Const a b]

Fractional a => Fractional (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

(/) :: Const a b -> Const a b -> Const a b

recip :: Const a b -> Const a b

fromRational :: Rational -> Const a b

Integral a => Integral (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

quot :: Const a b -> Const a b -> Const a b

rem :: Const a b -> Const a b -> Const a b

div :: Const a b -> Const a b -> Const a b

mod :: Const a b -> Const a b -> Const a b

quotRem :: Const a b -> Const a b -> (Const a b, Const a b)

divMod :: Const a b -> Const a b -> (Const a b, Const a b)

toInteger :: Const a b -> Integer

Real a => Real (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

toRational :: Const a b -> Rational

RealFrac a => RealFrac (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

properFraction :: Integral b0 => Const a b -> (b0, Const a b)

truncate :: Integral b0 => Const a b -> b0

round :: Integral b0 => Const a b -> b0

ceiling :: Integral b0 => Const a b -> b0

floor :: Integral b0 => Const a b -> b0

Show a => Show (Const a b)

This instance would be equivalent to the derived instances of the Const newtype if the getConst field were removed

Since: base-4.8.0.0

Defined in Data.Functor.Const

Methods

showsPrec :: Int -> Const a b -> ShowS

show :: Const a b -> String

showList :: [Const a b] -> ShowS

Eq a => Eq (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

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

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

Ord a => Ord (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

compare :: Const a b -> Const a b -> Ordering

(<) :: Const a b -> Const a b -> Bool

(<=) :: Const a b -> Const a b -> Bool

(>) :: Const a b -> Const a b -> Bool

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

max :: Const a b -> Const a b -> Const a b

min :: Const a b -> Const a b -> Const a b

type Rep1 (Const a :: k -> Type)

Since: base-4.9.0.0

Defined in Data.Functor.Const

type Rep1 (Const a :: k -> Type) = D1 ('MetaData "Const" "Data.Functor.Const" "base" 'True) (C1 ('MetaCons "Const" 'PrefixI 'True) (S1 ('MetaSel ('Just "getConst") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))

type Rep (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

type Rep (Const a b) = D1 ('MetaData "Const" "Data.Functor.Const" "base" 'True) (C1 ('MetaCons "Const" 'PrefixI 'True) (S1 ('MetaSel ('Just "getConst") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))

newtype ZipList a

Lists, but with an Applicative functor based on zipping.

Constructors

ZipList

Fields

• getZipList :: [a]

Instances

Foldable ZipList

Since: base-4.9.0.0

Defined in Control.Applicative

Methods

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

foldMap :: Monoid m => (a -> m) -> ZipList a -> m

foldMap' :: Monoid m => (a -> m) -> ZipList a -> m

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

foldr' :: (a -> b -> b) -> b -> ZipList a -> b

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

foldl' :: (b -> a -> b) -> b -> ZipList a -> b

foldr1 :: (a -> a -> a) -> ZipList a -> a

foldl1 :: (a -> a -> a) -> ZipList a -> a

toList :: ZipList a -> [a]

null :: ZipList a -> Bool

length :: ZipList a -> Int

elem :: Eq a => a -> ZipList a -> Bool

maximum :: Ord a => ZipList a -> a

minimum :: Ord a => ZipList a -> a

sum :: Num a => ZipList a -> a

product :: Num a => ZipList a -> a

Traversable ZipList

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> ZipList a -> f (ZipList b)

sequenceA :: Applicative f => ZipList (f a) -> f (ZipList a)

mapM :: Monad m => (a -> m b) -> ZipList a -> m (ZipList b)

sequence :: Monad m => ZipList (m a) -> m (ZipList a)

Alternative ZipList

Since: base-4.11.0.0

Defined in Control.Applicative

Methods

empty :: ZipList a

(<|>) :: ZipList a -> ZipList a -> ZipList a

some :: ZipList a -> ZipList [a]

many :: ZipList a -> ZipList [a]

Applicative ZipList

f <$> ZipList xs1 <*> ... <*> ZipList xsN
    = ZipList (zipWithN f xs1 ... xsN)

where zipWithN refers to the zipWith function of the appropriate arity (zipWith, zipWith3, zipWith4, ...). For example:

(\a b c -> stimes c [a, b]) <$> ZipList "abcd" <*> ZipList "567" <*> ZipList [1..]
    = ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..])
    = ZipList {getZipList = ["a5","b6b6","c7c7c7"]}

Since: base-2.1

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

Functor ZipList

Since: base-2.1

Defined in Control.Applicative

Methods

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

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

Generic1 ZipList

Defined in Control.Applicative

Associated Types

type Rep1 ZipList :: k -> Type

Methods

from1 :: forall (a :: k). ZipList a -> Rep1 ZipList a

to1 :: forall (a :: k). Rep1 ZipList a -> ZipList a

Generic (ZipList a)

Defined in Control.Applicative

Associated Types

type Rep (ZipList a) :: Type -> Type

Methods

from :: ZipList a -> Rep (ZipList a) x

to :: Rep (ZipList a) x -> ZipList a

IsList (ZipList a)

Since: base-4.15.0.0

Defined in GHC.IsList

Associated Types

type Item (ZipList a)

Methods

fromList :: [Item (ZipList a)] -> ZipList a

fromListN :: Int -> [Item (ZipList a)] -> ZipList a

toList :: ZipList a -> [Item (ZipList a)]

Read a => Read (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

readsPrec :: Int -> ReadS (ZipList a)

readList :: ReadS [ZipList a]

readPrec :: ReadPrec (ZipList a)

readListPrec :: ReadPrec [ZipList a]

Show a => Show (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

showsPrec :: Int -> ZipList a -> ShowS

show :: ZipList a -> String

showList :: [ZipList a] -> ShowS

Eq a => Eq (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

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

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

Ord a => Ord (ZipList a)

Since: base-4.7.0.0

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

type Rep1 ZipList

Since: base-4.7.0.0

Defined in Control.Applicative

type Rep1 ZipList = D1 ('MetaData "ZipList" "Control.Applicative" "base" 'True) (C1 ('MetaCons "ZipList" 'PrefixI 'True) (S1 ('MetaSel ('Just "getZipList") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 [])))

type Rep (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

type Rep (ZipList a) = D1 ('MetaData "ZipList" "Control.Applicative" "base" 'True) (C1 ('MetaCons "ZipList" 'PrefixI 'True) (S1 ('MetaSel ('Just "getZipList") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [a])))

type Item (ZipList a)

Defined in GHC.IsList

type Item (ZipList a) = a

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

A variant of <*> with the arguments reversed.

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

Lift a ternary function to actions.

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

One or none.

It is useful for modelling any computation that is allowed to fail.

Examples

Using the Alternative instance of Control.Monad.Except, the following functions:

>>> import Control.Monad.Except

>>> canFail = throwError "it failed" :: Except String Int
>>> final = return 42                :: Except String Int

Can be combined by allowing the first function to fail:

>>> runExcept $ canFail *> final
Left "it failed"
>>> runExcept $ optional canFail *> final
Right 42

(&&&) :: 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.

(>>>) :: forall {k} cat (a :: k) (b :: k) (c :: k). Category cat => cat a b -> cat b c -> cat a c infixr 1

Left-to-right composition

(<<<) :: forall {k} cat (b :: k) (c :: k) (a :: k). Category cat => cat b c -> cat a b -> cat a c infixr 1

Right-to-left composition

module Control.Concurrent.MVar

class (Typeable e, Show e) => Exception e

Any type that you wish to throw or catch as an exception must be an instance of the Exception class. The simplest case is a new exception type directly below the root:

data MyException = ThisException | ThatException
    deriving Show

instance Exception MyException

The default method definitions in the Exception class do what we need in this case. You can now throw and catch ThisException and ThatException as exceptions:

*Main> throw ThisException `catch` \e -> putStrLn ("Caught " ++ show (e :: MyException))
Caught ThisException

In more complicated examples, you may wish to define a whole hierarchy of exceptions:

---------------------------------------------------------------------
-- Make the root exception type for all the exceptions in a compiler

data SomeCompilerException = forall e . Exception e => SomeCompilerException e

instance Show SomeCompilerException where
    show (SomeCompilerException e) = show e

instance Exception SomeCompilerException

compilerExceptionToException :: Exception e => e -> SomeException
compilerExceptionToException = toException . SomeCompilerException

compilerExceptionFromException :: Exception e => SomeException -> Maybe e
compilerExceptionFromException x = do
    SomeCompilerException a <- fromException x
    cast a

---------------------------------------------------------------------
-- Make a subhierarchy for exceptions in the frontend of the compiler

data SomeFrontendException = forall e . Exception e => SomeFrontendException e

instance Show SomeFrontendException where
    show (SomeFrontendException e) = show e

instance Exception SomeFrontendException where
    toException = compilerExceptionToException
    fromException = compilerExceptionFromException

frontendExceptionToException :: Exception e => e -> SomeException
frontendExceptionToException = toException . SomeFrontendException

frontendExceptionFromException :: Exception e => SomeException -> Maybe e
frontendExceptionFromException x = do
    SomeFrontendException a <- fromException x
    cast a

---------------------------------------------------------------------
-- Make an exception type for a particular frontend compiler exception

data MismatchedParentheses = MismatchedParentheses
    deriving Show

instance Exception MismatchedParentheses where
    toException   = frontendExceptionToException
    fromException = frontendExceptionFromException

We can now catch a MismatchedParentheses exception as MismatchedParentheses, SomeFrontendException or SomeCompilerException, but not other types, e.g. IOException:

*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: MismatchedParentheses))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeFrontendException))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeCompilerException))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: IOException))
*** Exception: MismatchedParentheses

Instances

Exception Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

toException :: Void -> SomeException

fromException :: SomeException -> Maybe Void

displayException :: Void -> String

Exception ArithException

Since: base-4.0.0.0

Defined in GHC.Exception.Type

Methods

toException :: ArithException -> SomeException

fromException :: SomeException -> Maybe ArithException

displayException :: ArithException -> String

Exception SomeException

Since: base-3.0

Defined in GHC.Exception.Type

Methods

toException :: SomeException -> SomeException

fromException :: SomeException -> Maybe SomeException

displayException :: SomeException -> String

Exception UnicodeException

Defined in Data.Text.Encoding.Error

Methods

toException :: UnicodeException -> SomeException

fromException :: SomeException -> Maybe UnicodeException

displayException :: UnicodeException -> String

data SomeException

The SomeException type is the root of the exception type hierarchy. When an exception of type e is thrown, behind the scenes it is encapsulated in a SomeException.

Constructors

Exception e => SomeException e

Instances

Exception SomeException

Since: base-3.0

Defined in GHC.Exception.Type

Methods

toException :: SomeException -> SomeException

fromException :: SomeException -> Maybe SomeException

displayException :: SomeException -> String

Show SomeException

Since: base-3.0

Defined in GHC.Exception.Type

Methods

showsPrec :: Int -> SomeException -> ShowS

show :: SomeException -> String

showList :: [SomeException] -> ShowS

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

Monads that also support choice and failure.

Minimal complete definition

Nothing

Methods

mzero :: m a

The identity of mplus. It should also satisfy the equations

mzero >>= f  =  mzero
v >> mzero   =  mzero

The default definition is

mzero = empty

mplus :: m a -> m a -> m a

An associative operation. The default definition is

mplus = (<|>)

Instances

MonadPlus P

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

mzero :: P a

mplus :: P a -> P a -> P a

MonadPlus ReadP

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

mzero :: ReadP a

mplus :: ReadP a -> ReadP a -> ReadP a

MonadPlus Seq

Defined in Data.Sequence.Internal

Methods

mzero :: Seq a

mplus :: Seq a -> Seq a -> Seq a

MonadPlus DList

Defined in Data.DList.Internal

Methods

mzero :: DList a

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

Since: base-2.1

Defined in GHC.Base

Methods

mzero :: Maybe a

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

MonadPlus []

Since: base-2.1

Defined in GHC.Base

Methods

mzero :: [a]

mplus :: [a] -> [a] -> [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 :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Proxy

Methods

mzero :: Proxy a

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

MonadPlus (U1 :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

mzero :: U1 a

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

MonadPlus m => MonadPlus (Kleisli m a)

Since: base-4.14.0.0

Defined in Control.Arrow

Methods

mzero :: Kleisli m a a0

mplus :: Kleisli m a a0 -> Kleisli m a a0 -> Kleisli m a a0

MonadPlus f => MonadPlus (Ap f)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

mzero :: Ap f a

mplus :: Ap f a -> Ap f a -> Ap f 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 g) => MonadPlus (Product f g)

Since: base-4.9.0.0

Defined in Data.Functor.Product

Methods

mzero :: Product f g a

mplus :: Product f g a -> Product f g a -> Product f g 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

class Applicative m => Monad (m :: Type -> Type) where

The Monad class defines the basic operations over a monad, a concept from a branch of mathematics known as category theory. From the perspective of a Haskell programmer, however, it is best to think of a monad as an abstract datatype of actions. Haskell's do expressions provide a convenient syntax for writing monadic expressions.

Instances of Monad should satisfy the following:

Left identity

return a >>= k = k a

Right identity

m >>= return = m

Associativity

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

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

• pure = return

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

The above laws imply:

• fmap f xs  =  xs >>= return . f

• (>>) = (*>)

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

The instances of Monad for lists, Maybe and IO defined in the Prelude satisfy these laws.

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.

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

do a <- as
   bs a

(>>) :: m a -> m b -> m b infixl 1

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

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

do as
   bs

Instances

Monad Complex

Since: base-4.9.0.0

Defined in Data.Complex

Methods

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

(>>) :: Complex a -> Complex b -> Complex b

return :: a -> Complex a

Monad Identity

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

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

(>>) :: Identity a -> Identity b -> Identity b

return :: a -> Identity a

Monad First

Since: base-4.8.0.0

Defined in Data.Monoid

Methods

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

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

return :: a -> First a

Monad Last

Since: base-4.8.0.0

Defined in Data.Monoid

Methods

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

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

return :: a -> Last 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

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

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

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

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

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

Monad P

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

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

(>>) :: P a -> P b -> P b

return :: a -> P a

Monad ReadP

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

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

(>>) :: ReadP a -> ReadP b -> ReadP b

return :: a -> ReadP a

Monad Seq

Defined in Data.Sequence.Internal

Methods

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

(>>) :: Seq a -> Seq b -> Seq b

return :: a -> Seq a

Monad DList

Defined in Data.DList.Internal

Methods

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

(>>) :: DList a -> DList b -> DList b

return :: a -> DList 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

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

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

Monad Solo

Since: base-4.15

Defined in GHC.Base

Methods

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

(>>) :: Solo a -> Solo b -> Solo b

return :: a -> Solo a

Monad []

Since: base-2.1

Defined in GHC.Base

Methods

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

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

return :: a -> [a]

Monad m => Monad (WrappedMonad m)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

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

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

return :: a -> WrappedMonad m a

ArrowApply a => Monad (ArrowMonad a)

Since: base-2.1

Defined in Control.Arrow

Methods

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

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

return :: a0 -> ArrowMonad a a0

Monad (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

Monad (Proxy :: Type -> Type)

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

Monad (U1 :: Type -> Type)

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

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)

Monad m => Monad (Kleisli m a)

Since: base-4.14.0.0

Defined in Control.Arrow

Methods

(>>=) :: Kleisli m a a0 -> (a0 -> Kleisli m a b) -> Kleisli m a b

(>>) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a b

return :: a0 -> Kleisli m a a0

Monad f => Monad (Ap f)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

(>>=) :: Ap f a -> (a -> Ap f b) -> Ap f b

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

return :: a -> Ap f a

Monad f => Monad (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

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

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

Since: containers-0.5.9

Defined in Data.IntMap.Internal

Methods

(>>=) :: WhenMissing f x a -> (a -> WhenMissing f x b) -> WhenMissing f x b

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

return :: a -> WhenMissing f x a

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

Since: base-4.14.0.0

Defined in GHC.Base

Methods

(>>=) :: (a, b, a0) -> (a0 -> (a, b, b0)) -> (a, b, b0)

(>>) :: (a, b, a0) -> (a, b, b0) -> (a, b, b0)

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

(Monad f, Monad g) => Monad (Product f g)

Since: base-4.9.0.0

Defined in Data.Functor.Product

Methods

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

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

return :: a -> Product f g a

(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

(Monad f, Applicative f) => Monad (WhenMatched f x y)

Equivalent to ReaderT Key (ReaderT x (ReaderT y (MaybeT f)))

Since: containers-0.5.9

Defined in Data.IntMap.Internal

Methods

(>>=) :: WhenMatched f x y a -> (a -> WhenMatched f x y b) -> WhenMatched f x y b

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

return :: a -> WhenMatched f x y 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

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

Since: base-4.14.0.0

Defined in GHC.Base

Methods

(>>=) :: (a, b, c, a0) -> (a0 -> (a, b, c, b0)) -> (a, b, c, b0)

(>>) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, b0)

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

Monad ((->) 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

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

(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

forever :: Applicative f => f a -> f b

Repeat an action indefinitely.

Examples

A common use of forever is to process input from network sockets, Handles, and channels (e.g. MVar and Chan).

For example, here is how we might implement an echo server, using forever both to listen for client connections on a network socket and to echo client input on client connection handles:

echoServer :: Socket -> IO ()
echoServer socket = forever $ do
  client <- accept socket
  forkFinally (echo client) (\_ -> hClose client)
  where
    echo :: Handle -> IO ()
    echo client = forever $
      hGetLine client >>= hPutStrLn client

Note that "forever" isn't necessarily non-terminating. If the action is in a MonadPlus and short-circuits after some number of iterations. then forever actually returns mzero, effectively short-circuiting its caller.

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.

'join bss' can be understood as the do expression

do bs <- bss
   bs

Examples

A common use of join is to run an IO computation returned from an STM transaction, since STM transactions can't perform IO directly. Recall that

atomically :: STM a -> IO a

is used to run STM transactions atomically. So, by specializing the types of atomically and join to

atomically :: STM (IO b) -> IO (IO b)
join       :: IO (IO b)  -> IO b

we can compose them as

join . atomically :: STM (IO b) -> IO b

to run an STM transaction and the IO action it returns.

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

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

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.

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

This generalizes the list-based filter function.

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

Left-to-right composition of Kleisli arrows.

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

do b <- bs a
   cs b

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

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

Note how this operator resembles function composition (.):

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

zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c]

The zipWithM function generalizes zipWith to arbitrary applicative functors.

zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m ()

zipWithM_ is the extension of zipWithM which ignores the final result.

replicateM :: Applicative m => Int -> m a -> m [a]

replicateM n act performs the action act n times, and then returns the list of results:

Examples

>>> import Control.Monad.State
>>> runState (replicateM 3 $ state $ \s -> (s, s + 1)) 1
([1,2,3],4)

replicateM_ :: Applicative m => Int -> m a -> m ()

Like replicateM, but discards the result.

Examples

>>> replicateM_ 3 (putStrLn "a")
a
a
a

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

The reverse of when.

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

Strict version of <$>.

Since: base-4.8.0.0

mfilter :: MonadPlus m => (a -> Bool) -> m a -> m a

Direct MonadPlus equivalent of filter.

Examples

The filter function is just mfilter specialized to the list monad:

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

An example using mfilter with the Maybe monad:

>>> mfilter odd (Just 1)
Just 1
>>> mfilter odd (Just 2)
Nothing

class Monad m => MonadFail (m :: Type -> Type) where

When a value is bound in do-notation, the pattern on the left hand side of <- might not match. In this case, this class provides a function to recover.

A Monad without a MonadFail instance may only be used in conjunction with pattern that always match, such as newtypes, tuples, data types with only a single data constructor, and irrefutable patterns (~pat).

Instances of MonadFail should satisfy the following law: fail s should be a left zero for >>=,

fail s >>= f  =  fail s

If your Monad is also MonadPlus, a popular definition is

fail _ = mzero

Since: base-4.9.0.0

Methods

fail :: String -> m a

Instances

MonadFail P

Since: base-4.9.0.0

Defined in Text.ParserCombinators.ReadP

Methods

fail :: String -> P a

MonadFail ReadP

Since: base-4.9.0.0

Defined in Text.ParserCombinators.ReadP

Methods

fail :: String -> ReadP a

MonadFail DList

Defined in Data.DList.Internal

Methods

fail :: String -> DList a

MonadFail IO

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> IO a

MonadFail Maybe

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> Maybe a

MonadFail []

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> [a]

MonadFail f => MonadFail (Ap f)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

fail :: String -> Ap f a

module Control.Monad.IO.Class

class Bifunctor (p :: Type -> Type -> Type) where

A bifunctor is a type constructor that takes two type arguments and is a functor in both arguments. That is, unlike with Functor, a type constructor such as Either does not need to be partially applied for a Bifunctor instance, and the methods in this class permit mapping functions over the Left value or the Right value, or both at the same time.

Formally, the class Bifunctor represents a bifunctor from Hask -> Hask.

Intuitively it is a bifunctor where both the first and second arguments are covariant.

You can define a Bifunctor by either defining bimap or by defining both first and second.

If you supply bimap, you should ensure that:

bimap id id ≡ id

If you supply first and second, ensure:

first id ≡ id
second id ≡ id

If you supply both, you should also ensure:

bimap f g ≡ first f . second g

These ensure by parametricity:

bimap  (f . g) (h . i) ≡ bimap f h . bimap g i
first  (f . g) ≡ first  f . first  g
second (f . g) ≡ second f . second g

Since: base-4.8.0.0

Minimal complete definition

bimap | first, second

Methods

bimap :: (a -> b) -> (c -> d) -> p a c -> p b d

Map over both arguments at the same time.

bimap f g ≡ first f . second g

Examples

>>> 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 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 (,)

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 (Const :: Type -> Type -> Type)

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 ((,,) 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 (K1 i :: Type -> Type -> Type)

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)

xor :: Bits a => a -> a -> a infixl 6

Bitwise "xor"

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

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

A simpler version of this function is:

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

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

Since: base-4.8.0.0

data Bool

Constructors

False

True

Instances

Bits Bool

Interpret Bool as 1-bit bit-field

Since: base-4.7.0.0

Defined in GHC.Bits

Methods

(.&.) :: Bool -> Bool -> Bool

(.|.) :: Bool -> Bool -> Bool

xor :: Bool -> Bool -> Bool

complement :: Bool -> Bool

shift :: Bool -> Int -> Bool

rotate :: Bool -> Int -> Bool

zeroBits :: Bool

bit :: Int -> Bool

setBit :: Bool -> Int -> Bool

clearBit :: Bool -> Int -> Bool

complementBit :: Bool -> Int -> Bool

testBit :: Bool -> Int -> Bool

bitSizeMaybe :: Bool -> Maybe Int

bitSize :: Bool -> Int

isSigned :: Bool -> Bool

shiftL :: Bool -> Int -> Bool

unsafeShiftL :: Bool -> Int -> Bool

shiftR :: Bool -> Int -> Bool

unsafeShiftR :: Bool -> Int -> Bool

rotateL :: Bool -> Int -> Bool

rotateR :: Bool -> Int -> Bool

popCount :: Bool -> Int

FiniteBits Bool

Since: base-4.7.0.0

Defined in GHC.Bits

Methods

finiteBitSize :: Bool -> Int

countLeadingZeros :: Bool -> Int

countTrailingZeros :: Bool -> Int

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]

Generic Bool

Defined in GHC.Generics

Associated Types

type Rep Bool :: Type -> Type

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 :: forall (a :: Bool). Sing a -> DemoteRep 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

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Bool -> ShowS

show :: Bool -> String

showList :: [Bool] -> ShowS

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

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 DemoteRep Bool

Defined in GHC.Generics

type DemoteRep Bool = Bool

type Rep Bool

Since: base-4.6.0.0

Defined in GHC.Generics

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

data Sing (a :: Bool)

Defined in GHC.Generics

data Sing (a :: Bool) where

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

otherwise :: Bool

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

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

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

Boolean "and", lazy in the second argument

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

Boolean "or", lazy in the second argument

not :: Bool -> Bool

Boolean "not"

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

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

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

Examples

Basic usage:

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

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

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

Since: base-4.7.0.0

data 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]

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

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

ToLText String

Defined in Incipit.String.Conversion

Methods

toLText :: String -> LText

ToString String

Defined in Incipit.String.Conversion

Methods

toString :: String -> String

ToText String

Defined in Incipit.String.Conversion

Methods

toText :: String -> Text

ConvertUtf8 String ByteString

Defined in Incipit.String.Conversion

Methods

encodeUtf8 :: String -> ByteString

decodeUtf8 :: ByteString -> String

decodeUtf8Strict :: ByteString -> Either UnicodeException String

ConvertUtf8 String ShortByteString

Since: 0.6.0.0

Defined in Incipit.String.Conversion

Methods

encodeUtf8 :: String -> ShortByteString

decodeUtf8 :: ShortByteString -> String

decodeUtf8Strict :: ShortByteString -> Either UnicodeException String

ConvertUtf8 String LByteString

Converting String to ByteString might be a slow operation. Consider using lazy bytestring at first place.

Defined in Incipit.String.Conversion

Methods

encodeUtf8 :: String -> LByteString

decodeUtf8 :: LByteString -> String

decodeUtf8Strict :: LByteString -> Either UnicodeException String

Generic1 (URec Char :: k -> Type)

Defined in GHC.Generics

Associated Types

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

Methods

from1 :: forall (a :: k0). URec Char a -> Rep1 (URec Char) a

to1 :: forall (a :: k0). Rep1 (URec Char) a -> URec Char a

Foldable (UChar :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => UChar m -> m

foldMap :: Monoid m => (a -> m) -> UChar a -> m

foldMap' :: Monoid m => (a -> m) -> UChar a -> m

foldr :: (a -> b -> b) -> b -> UChar a -> b

foldr' :: (a -> b -> b) -> b -> UChar a -> b

foldl :: (b -> a -> b) -> b -> UChar a -> b

foldl' :: (b -> a -> b) -> b -> UChar a -> b

foldr1 :: (a -> a -> a) -> UChar a -> a

foldl1 :: (a -> a -> a) -> UChar a -> a

toList :: UChar a -> [a]

null :: UChar a -> Bool

length :: UChar a -> Int

elem :: Eq a => a -> UChar a -> Bool

maximum :: Ord a => UChar a -> a

minimum :: Ord a => UChar a -> a

sum :: Num a => UChar a -> a

product :: Num a => UChar a -> a

Traversable (UChar :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UChar a -> f (UChar b)

sequenceA :: Applicative f => UChar (f a) -> f (UChar a)

mapM :: Monad m => (a -> m b) -> UChar a -> m (UChar b)

sequence :: Monad m => UChar (m a) -> m (UChar a)

Functor (URec Char :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Generic (URec Char p)

Defined in GHC.Generics

Associated Types

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

Methods

from :: URec Char p -> Rep (URec Char p) x

to :: Rep (URec Char p) x -> URec Char p

Show (URec Char p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> URec Char p -> ShowS

show :: URec Char p -> String

showList :: [URec Char p] -> ShowS

Eq (URec Char p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Ord (URec Char p)

Since: base-4.9.0.0

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

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 Compare (a :: Char) (b :: Char)

Defined in Data.Type.Ord

type Compare (a :: Char) (b :: Char) = CmpChar a b

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

Since: base-4.9.0.0

Defined in GHC.Generics

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

type Rep (URec Char p)

Since: base-4.9.0.0

Defined in GHC.Generics

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

chr :: Int -> Char

The toEnum method restricted to the type Char.

class a ~R# b => Coercible (a :: k) (b :: k)

Coercible is a two-parameter class that has instances for types a and b if the compiler can infer that they have the same representation. This class does not have regular instances; instead they are created on-the-fly during type-checking. Trying to manually declare an instance of Coercible is an error.

Nevertheless one can pretend that the following three kinds of instances exist. First, as a trivial base-case:

instance Coercible a a

Furthermore, for every type constructor there is an instance that allows to coerce under the type constructor. For example, let D be a prototypical type constructor (data or newtype) with three type arguments, which have roles nominal, representational resp. phantom. Then there is an instance of the form

instance Coercible b b' => Coercible (D a b c) (D a b' c')

Note that the nominal type arguments are equal, the representational type arguments can differ, but need to have a Coercible instance themself, and the phantom type arguments can be changed arbitrarily.

The third kind of instance exists for every newtype NT = MkNT T and comes in two variants, namely

instance Coercible a T => Coercible a NT

instance Coercible T b => Coercible NT b

This instance is only usable if the constructor MkNT is in scope.

If, as a library author of a type constructor like Set a, you want to prevent a user of your module to write coerce :: Set T -> Set NT, you need to set the role of Set's type parameter to nominal, by writing

type role Set nominal

For more details about this feature, please refer to Safe Coercions by Joachim Breitner, Richard A. Eisenberg, Simon Peyton Jones and Stephanie Weirich.

Since: ghc-prim-0.4.0

coerce :: forall {k :: RuntimeRep} (a :: TYPE k) (b :: TYPE k). Coercible a b => a -> b

The function coerce allows you to safely convert between values of types that have the same representation with no run-time overhead. In the simplest case you can use it instead of a newtype constructor, to go from the newtype's concrete type to the abstract type. But it also works in more complicated settings, e.g. converting a list of newtypes to a list of concrete types.

This function is representation-polymorphic, but the RuntimeRep type argument is marked as Inferred, meaning that it is not available for visible type application. This means the typechecker will accept coerce @Int @Age 42.

module Data.Either

class Eq a where

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

The Haskell Report defines no laws for Eq. However, instances are encouraged to follow these properties:

Reflexivity

x == x = True

Symmetry

x == y = y == x

Transitivity

if x == y && y == z = True, then x == z = True

Extensionality

if x == y = True and f is a function whose return type is an instance of Eq, then f x == f y = True

Negation

x /= y = not (x == y)

Minimal complete definition: either == or /=.

Minimal complete definition

(==) | (/=)

Methods

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

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

Instances

Eq SomeTypeRep

Defined in Data.Typeable.Internal

Methods

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

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

Eq Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

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

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

Eq ArithException

Since: base-3.0

Defined in GHC.Exception.Type

Methods

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

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

Eq Associativity

Since: base-4.6.0.0

Defined in GHC.Generics

Methods

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

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

Eq DecidedStrictness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Eq Fixity

Since: base-4.6.0.0

Defined in GHC.Generics

Methods

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

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

Eq SourceStrictness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Eq SourceUnpackedness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Eq MaskingState

Since: base-4.3.0.0

Defined in GHC.IO

Methods

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

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

Since: base-2.1

Defined in GHC.Int

Methods

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

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

Eq SrcLoc

Since: base-4.9.0.0

Defined in GHC.Stack.Types

Methods

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

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

Eq SomeChar

Defined in GHC.TypeLits

Methods

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

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

Eq SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

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

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

Eq SomeNat

Since: base-4.7.0.0

Defined in GHC.TypeNats

Methods

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

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

Eq Word16

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word16 -> Word16 -> Bool

(/=) :: Word16 -> Word16 -> Bool

Eq Word32

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word32 -> Word32 -> Bool

(/=) :: Word32 -> Word32 -> Bool

Eq Word64

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word64 -> Word64 -> Bool

(/=) :: Word64 -> Word64 -> Bool

Eq Word8

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word8 -> Word8 -> Bool

(/=) :: Word8 -> Word8 -> Bool

Eq ByteString

Defined in Data.ByteString.Internal.Type

Methods

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

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

Eq ByteString

Defined in Data.ByteString.Lazy.Internal

Methods

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

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

Eq ShortByteString

Defined in Data.ByteString.Short.Internal

Methods

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

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

Eq IntSet

Defined in Data.IntSet.Internal

Methods

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

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

Eq BigNat

Defined in GHC.Num.BigNat

Methods

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

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

Eq Module

Defined in GHC.Classes

Methods

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

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

Eq Ordering

Defined in GHC.Classes

Methods

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

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

Eq TrName

Defined in GHC.Classes

Methods

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

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

Eq TyCon

Defined in GHC.Classes

Methods

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

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

Eq UnicodeException

Defined in Data.Text.Encoding.Error

Methods

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

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

Eq Integer

Defined in GHC.Num.Integer

Methods

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

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

Eq Natural

Defined in GHC.Num.Natural

Methods

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

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

Eq ()

Defined in GHC.Classes

Methods

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

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

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

Note that due to the presence of NaN, Double's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Double)
False

Also note that Double's Eq instance does not satisfy substitutivity:

>>> 0 == (-0 :: Double)
True
>>> recip 0 == recip (-0 :: Double)
False

Defined in GHC.Classes

Methods

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

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

Eq Float

Note that due to the presence of NaN, Float's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Float)
False

Also note that Float's Eq instance does not satisfy extensionality:

>>> 0 == (-0 :: Float)
True
>>> recip 0 == recip (-0 :: Float)
False

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 Word

Defined in GHC.Classes

Methods

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

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

Eq a => Eq (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

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

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

Eq a => Eq (And a)

Since: base-4.16

Defined in Data.Bits

Methods

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

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

Eq a => Eq (Iff a)

Since: base-4.16

Defined in Data.Bits

Methods

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

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

Eq a => Eq (Ior a)

Since: base-4.16

Defined in Data.Bits

Methods

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

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

Eq a => Eq (Xor a)

Since: base-4.16

Defined in Data.Bits

Methods

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

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

Eq a => Eq (Complex a)

Since: base-2.1

Defined in Data.Complex

Methods

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

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

Eq a => Eq (Identity a)

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

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

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

Eq a => Eq (First a)

Since: base-2.1

Defined in Data.Monoid

Methods

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

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

Eq a => Eq (Last a)

Since: base-2.1

Defined in Data.Monoid

Methods

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

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

Eq a => Eq (Down a)

Since: base-4.6.0.0

Defined in Data.Ord

Methods

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

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

Eq a => Eq (First a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

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

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

Eq a => Eq (Last a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

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

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

Eq a => Eq (Max a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

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

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

Eq a => Eq (Min a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

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

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

Eq m => Eq (WrappedMonoid m)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

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

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

Eq p => Eq (Par1 p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

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

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

Eq (MVar a)

Since: base-4.1.0.0

Defined in GHC.MVar

Methods

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

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

Eq a => Eq (Ratio a)

Since: base-2.1

Defined in GHC.Real

Methods

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

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

Eq a => Eq (IntMap a)

Defined in Data.IntMap.Internal

Methods

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

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

Eq a => Eq (Seq a)

Defined in Data.Sequence.Internal

Methods

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

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

Eq a => Eq (ViewL a)

Defined in Data.Sequence.Internal

Methods

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

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

Eq a => Eq (ViewR a)

Defined in Data.Sequence.Internal

Methods

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

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

Eq a => Eq (Intersection a)

Defined in Data.Set.Internal

Methods

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

(/=) :: Intersection a -> Intersection 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 (DList a)

Defined in Data.DList.Internal

Methods

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

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

Eq a => Eq (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

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

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

Eq a => Eq (Maybe a)

Since: base-2.1

Defined in GHC.Maybe

Methods

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

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

Eq a => Eq (a)

Defined in GHC.Classes

Methods

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

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

Eq a => Eq [a]

Defined in GHC.Classes

Methods

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

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

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

Since: base-2.1

Defined in Data.Either

Methods

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

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

Eq (Fixed a)

Since: base-2.1

Defined in Data.Fixed

Methods

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

(/=) :: Fixed a -> Fixed a -> 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 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 (TypeRep a)

Since: base-2.1

Defined in Data.Typeable.Internal

Methods

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

(/=) :: TypeRep a -> TypeRep a -> 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 (V1 p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

(/=) :: V1 p -> V1 p -> 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 a, Eq b) => Eq (a, b)

Defined in GHC.Classes

Methods

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

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

Eq a => Eq (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

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

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

Eq (f a) => Eq (Ap f a)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

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

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

Eq (a :~: b)

Since: base-4.7.0.0

Defined in Data.Type.Equality

Methods

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

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

Eq (OrderingI a b)

Defined in Data.Type.Ord

Methods

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

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

Eq (f p) => Eq (Rec1 f p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

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

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

Eq (URec (Ptr ()) p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Eq (URec Char p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Eq (URec Double p)

Since: base-4.9.0.0

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)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Eq (URec Word p)

Since: base-4.9.0.0

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

(Eq1 f, Eq1 g, Eq a) => Eq (Product f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Product

Methods

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

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

(Eq1 f, Eq1 g, Eq a) => Eq (Sum f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Sum

Methods

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

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

Eq (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 (g p)) => Eq ((f :*: g) p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

(==) :: (f :*: g) p -> (f :*: g) p -> Bool

(/=) :: (f :*: g) p -> (f :*: g) p -> Bool

(Eq (f p), Eq (g p)) => Eq ((f :+: g) p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

(==) :: (f :+: g) p -> (f :+: g) p -> Bool

(/=) :: (f :+: g) p -> (f :+: g) p -> Bool

Eq c => Eq (K1 i c p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

(==) :: K1 i c p -> K1 i c p -> Bool

(/=) :: K1 i c p -> K1 i c 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

(Eq1 f, Eq1 g, Eq a) => Eq (Compose f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

(==) :: Compose f g a -> Compose f g a -> Bool

(/=) :: Compose f g a -> Compose f g a -> Bool

Eq (f (g p)) => Eq ((f :.: g) p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

(==) :: (f :.: g) p -> (f :.: g) p -> Bool

(/=) :: (f :.: g) p -> (f :.: g) p -> Bool

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

Since: base-4.7.0.0

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 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

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

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

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

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

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

id :: a -> a

Identity function.

id x = x

const :: a -> b -> a

const x y always evaluates to x, ignoring its second argument.

>>> const 42 "hello"
42

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

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

Function composition.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Algebraic properties:

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

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

• flip on f . flip on g = flip on (g . f)

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

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

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

Since: base-4.8.0.0

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

A type f is a Functor if it provides a function fmap which, given any types a and b lets you apply any function from (a -> b) to turn an f a into an f b, preserving the structure of f. Furthermore f needs to adhere to the following:

Identity

fmap id == id

Composition

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

Note, that the second law follows from the free theorem of the type fmap and the first law, so you need only check that the former condition holds. See https://www.schoolofhaskell.com/user/edwardk/snippets/fmap or https://github.com/quchen/articles/blob/master/second_functor_law.md for an explanation.

Minimal complete definition

fmap

Methods

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

fmap is used to apply a function of type (a -> b) to a value of type f a, where f is a functor, to produce a value of type f b. Note that for any type constructor with more than one parameter (e.g., Either), only the last type parameter can be modified with fmap (e.g., b in `Either a b`).

Some type constructors with two parameters or more have a Bifunctor instance that allows both the last and the penultimate parameters to be mapped over.

Examples

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

>>> fmap show Nothing
Nothing
>>> fmap show (Just 3)
Just "3"

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

>>> fmap show (Left 17)
Left 17
>>> fmap show (Right 17)
Right "17"

Double each element of a list:

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

Apply even to the second element of a pair:

>>> fmap even (2,2)
(2,True)

It may seem surprising that the function is only applied to the last element of the tuple compared to the list example above which applies it to every element in the list. To understand, remember that tuples are type constructors with multiple type parameters: a tuple of 3 elements (a,b,c) can also be written (,,) a b c and its Functor instance is defined for Functor ((,,) a b) (i.e., only the third parameter is free to be mapped over with fmap).

It explains why fmap can be used with tuples containing values of different types as in the following example:

>>> fmap even ("hello", 1.0, 4)
("hello",1.0,True)

(<$) :: 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 ZipList

Since: base-2.1

Defined in Control.Applicative

Methods

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

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

Functor Handler

Since: base-4.6.0.0

Defined in Control.Exception

Methods

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

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

Functor Complex

Since: base-4.9.0.0

Defined in Data.Complex

Methods

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

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

Functor Identity

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

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

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

Functor First

Since: base-4.8.0.0

Defined in Data.Monoid

Methods

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

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

Functor Last

Since: base-4.8.0.0

Defined in Data.Monoid

Methods

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

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

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Functor P

Since: base-4.8.0.0

Defined in Text.ParserCombinators.ReadP

Methods

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

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

Functor ReadP

Since: base-2.1

Defined in Text.ParserCombinators.ReadP

Methods

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

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

Functor IntMap

Defined in Data.IntMap.Internal

Methods

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

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

Functor Digit

Defined in Data.Sequence.Internal

Methods

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

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

Functor Elem

Defined in Data.Sequence.Internal

Methods

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

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

Functor FingerTree

Defined in Data.Sequence.Internal

Methods

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

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

Functor Node

Defined in Data.Sequence.Internal

Methods

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

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

Functor Seq

Defined in Data.Sequence.Internal

Methods

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

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

Functor ViewL

Defined in Data.Sequence.Internal

Methods

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

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

Functor ViewR

Defined in Data.Sequence.Internal

Methods

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

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

Functor DList

Defined in Data.DList.Internal

Methods

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

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

Since: base-2.1

Defined in GHC.Base

Methods

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

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

Functor Solo

Since: base-4.15

Defined in GHC.Base

Methods

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

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

Functor []

Since: base-2.1

Defined in GHC.Base

Methods

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

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

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 (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 (Proxy :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

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

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

Functor (U1 :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Functor (V1 :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Since: base-2.1

Defined in GHC.Base

Methods

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

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

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 m => Functor (Kleisli m a)

Since: base-4.14.0.0

Defined in Control.Arrow

Methods

fmap :: (a0 -> b) -> Kleisli m a a0 -> Kleisli m a b

(<$) :: a0 -> Kleisli m a b -> Kleisli m a a0

Functor (Const m :: Type -> Type)

Since: base-2.1

Defined in Data.Functor.Const

Methods

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

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

Functor f => Functor (Ap f)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

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

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

(Generic1 f, Functor (Rep1 f)) => Functor (Generically1 f)

Since: base-4.17.0.0

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> Generically1 f a -> Generically1 f b

(<$) :: a -> Generically1 f b -> Generically1 f a

Functor f => Functor (Rec1 f)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

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

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Functor (URec Char :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Functor (URec Double :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Functor (URec Float :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Functor (URec Int :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Functor (URec Word :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

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

Since: containers-0.5.9

Defined in Data.IntMap.Internal

Methods

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

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

Functor ((,,) a b)

Since: base-4.14.0.0

Defined in GHC.Base

Methods

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

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

(Functor f, Functor g) => Functor (Product f g)

Since: base-4.9.0.0

Defined in Data.Functor.Product

Methods

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

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

(Functor f, Functor g) => Functor (Sum f g)

Since: base-4.9.0.0

Defined in Data.Functor.Sum

Methods

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

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

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

Since: base-4.9.0.0

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)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

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

Since: base-4.9.0.0

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 (WhenMatched f x y)

Since: containers-0.5.9

Defined in Data.IntMap.Internal

Methods

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

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

Since: base-4.14.0.0

Defined in GHC.Base

Methods

fmap :: (a0 -> b0) -> (a, b, c, a0) -> (a, b, c, b0)

(<$) :: a0 -> (a, b, c, b0) -> (a, b, c, a0)

Functor ((->) r)

Since: base-2.1

Defined in GHC.Base

Methods

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

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

(Functor f, Functor g) => Functor (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

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

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

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

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Functor f => Functor (M1 i c f)

Since: base-4.9.0.0

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 (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

(<$>) :: 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)

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 -> (a -> b) -> f b infixl 1

Flipped version of <$>.

(<&>) = flip fmap

Examples

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

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

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

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

Since: base-4.11.0.0

($>) :: Functor f => 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

newtype Compose (f :: k -> Type) (g :: k1 -> k) (a :: k1) infixr 9

Right-to-left composition of functors. The composition of applicative functors is always applicative, but the composition of monads is not always a monad.

Constructors

Compose infixr 9

Fields

• getCompose :: f (g a)

Instances

TestEquality f => TestEquality (Compose f g :: k2 -> Type)

The deduction (via generativity) that if g x :~: g y then x :~: y.

Since: base-4.14.0.0

Defined in Data.Functor.Compose

Methods

testEquality :: forall (a :: k) (b :: k). Compose f g a -> Compose f g b -> Maybe (a :~: b)

Functor f => Generic1 (Compose f g :: k -> Type)

Defined in Data.Functor.Compose

Associated Types

type Rep1 (Compose f g) :: k -> Type

Methods

from1 :: forall (a :: k0). Compose f g a -> Rep1 (Compose f g) a

to1 :: forall (a :: k0). Rep1 (Compose f g) a -> Compose f g a

(Foldable f, Foldable g) => Foldable (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

fold :: Monoid m => Compose f g m -> m

foldMap :: Monoid m => (a -> m) -> Compose f g a -> m

foldMap' :: Monoid m => (a -> m) -> Compose f g a -> m

foldr :: (a -> b -> b) -> b -> Compose f g a -> b

foldr' :: (a -> b -> b) -> b -> Compose f g a -> b

foldl :: (b -> a -> b) -> b -> Compose f g a -> b

foldl' :: (b -> a -> b) -> b -> Compose f g a -> b

foldr1 :: (a -> a -> a) -> Compose f g a -> a

foldl1 :: (a -> a -> a) -> Compose f g a -> a

toList :: Compose f g a -> [a]

null :: Compose f g a -> Bool

length :: Compose f g a -> Int

elem :: Eq a => a -> Compose f g a -> Bool

maximum :: Ord a => Compose f g a -> a

minimum :: Ord a => Compose f g a -> a

sum :: Num a => Compose f g a -> a

product :: Num a => Compose f g a -> a

(Eq1 f, Eq1 g) => Eq1 (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

liftEq :: (a -> b -> Bool) -> Compose f g a -> Compose f g b -> Bool

(Ord1 f, Ord1 g) => Ord1 (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

liftCompare :: (a -> b -> Ordering) -> Compose f g a -> Compose f g b -> Ordering

(Read1 f, Read1 g) => Read1 (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Compose f g a)

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Compose f g a]

liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Compose f g a)

liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Compose f g a]

(Show1 f, Show1 g) => Show1 (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Compose f g a -> ShowS

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Compose f g a] -> ShowS

(Functor f, Contravariant g) => Contravariant (Compose f g)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Compose f g a -> Compose f g a'

(>$) :: b -> Compose f g b -> Compose f g a

(Traversable f, Traversable g) => Traversable (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Compose f g a -> f0 (Compose f g b)

sequenceA :: Applicative f0 => Compose f g (f0 a) -> f0 (Compose f g a)

mapM :: Monad m => (a -> m b) -> Compose f g a -> m (Compose f g b)

sequence :: Monad m => Compose f g (m a) -> m (Compose f g a)

(Alternative f, Applicative g) => Alternative (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

empty :: Compose f g a

(<|>) :: Compose f g a -> Compose f g a -> Compose f g a

some :: Compose f g a -> Compose f g [a]

many :: Compose f g a -> Compose f g [a]

(Applicative f, Applicative g) => Applicative (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

pure :: a -> Compose f g a

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

liftA2 :: (a -> b -> c) -> Compose f g a -> Compose f g b -> Compose f g c

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

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

(Functor f, Functor g) => Functor (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

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

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

(Typeable a, Typeable f, Typeable g, Typeable k1, Typeable k2, Data (f (g a))) => Data (Compose f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g0. g0 -> c g0) -> Compose f g a -> c (Compose f g a)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Compose f g a)

toConstr :: Compose f g a -> Constr

dataTypeOf :: Compose f g a -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Compose f g a))

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Compose f g a))

gmapT :: (forall b. Data b => b -> b) -> Compose f g a -> Compose f g a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Compose f g a -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Compose f g a -> r

gmapQ :: (forall d. Data d => d -> u) -> Compose f g a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Compose f g a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Compose f g a -> m (Compose f g a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Compose f g a -> m (Compose f g a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Compose f g a -> m (Compose f g a)

Monoid (f (g a)) => Monoid (Compose f g a)

Since: base-4.16.0.0

Defined in Data.Functor.Compose

Methods

mempty :: Compose f g a

mappend :: Compose f g a -> Compose f g a -> Compose f g a

mconcat :: [Compose f g a] -> Compose f g a

Semigroup (f (g a)) => Semigroup (Compose f g a)

Since: base-4.16.0.0

Defined in Data.Functor.Compose

Methods

(<>) :: Compose f g a -> Compose f g a -> Compose f g a

sconcat :: NonEmpty (Compose f g a) -> Compose f g a

stimes :: Integral b => b -> Compose f g a -> Compose f g a

Generic (Compose f g a)

Defined in Data.Functor.Compose

Associated Types

type Rep (Compose f g a) :: Type -> Type

Methods

from :: Compose f g a -> Rep (Compose f g a) x

to :: Rep (Compose f g a) x -> Compose f g a

(Read1 f, Read1 g, Read a) => Read (Compose f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

readsPrec :: Int -> ReadS (Compose f g a)

readList :: ReadS [Compose f g a]

readPrec :: ReadPrec (Compose f g a)

readListPrec :: ReadPrec [Compose f g a]

(Show1 f, Show1 g, Show a) => Show (Compose f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

showsPrec :: Int -> Compose f g a -> ShowS

show :: Compose f g a -> String

showList :: [Compose f g a] -> ShowS

(Eq1 f, Eq1 g, Eq a) => Eq (Compose f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

(==) :: Compose f g a -> Compose f g a -> Bool

(/=) :: Compose f g a -> Compose f g a -> Bool

(Ord1 f, Ord1 g, Ord a) => Ord (Compose f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

compare :: Compose f g a -> Compose f g a -> Ordering

(<) :: Compose f g a -> Compose f g a -> Bool

(<=) :: Compose f g a -> Compose f g a -> Bool

(>) :: Compose f g a -> Compose f g a -> Bool

(>=) :: Compose f g a -> Compose f g a -> Bool

max :: Compose f g a -> Compose f g a -> Compose f g a

min :: Compose f g a -> Compose f g a -> Compose f g a

type Rep1 (Compose f g :: k -> Type)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

type Rep1 (Compose f g :: k -> Type) = D1 ('MetaData "Compose" "Data.Functor.Compose" "base" 'True) (C1 ('MetaCons "Compose" 'PrefixI 'True) (S1 ('MetaSel ('Just "getCompose") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (f :.: Rec1 g)))

type Rep (Compose f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

type Rep (Compose f g a) = D1 ('MetaData "Compose" "Data.Functor.Compose" "base" 'True) (C1 ('MetaCons "Compose" 'PrefixI 'True) (S1 ('MetaSel ('Just "getCompose") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (f (g a)))))

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

The class of contravariant functors.

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

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

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

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

overdrawn :: Predicate Person
overdrawn = contramap personBankBalance negative

Any instance should be subject to the following laws:

Identity

contramap id = id

Composition

contramap (g . f) = contramap f . contramap g

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

Minimal complete definition

contramap

Methods

contramap :: (a' -> a) -> f a -> f a'

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

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

Instances

Contravariant Comparison

A Comparison is a Contravariant Functor, because contramap can apply its function argument to each input of the comparison function.

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Comparison a -> Comparison a'

(>$) :: b -> Comparison b -> Comparison a

Contravariant Equivalence

Equivalence relations are Contravariant, because you can apply the contramapped function to each input to the equivalence relation.

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Equivalence a -> Equivalence a'

(>$) :: b -> Equivalence b -> Equivalence a

Contravariant Predicate

A Predicate is a Contravariant Functor, because contramap can apply its function argument to the input of the predicate.

Without newtypes contramap f equals precomposing with f (= (. f)).

contramap :: (a' -> a) -> (Predicate a -> Predicate a')
contramap f (Predicate g) = Predicate (g . f)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Predicate a -> Predicate a'

(>$) :: b -> Predicate b -> Predicate a

Contravariant (Op a)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a0) -> Op a a0 -> Op a a'

(>$) :: b -> Op a b -> Op a a0

Contravariant (Proxy :: Type -> Type)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Proxy a -> Proxy a'

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

Contravariant (U1 :: Type -> Type)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> U1 a -> U1 a'

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

Contravariant (V1 :: Type -> Type)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> V1 a -> V1 a'

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

Contravariant (Const a :: Type -> Type)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a0) -> Const a a0 -> Const a a'

(>$) :: b -> Const a b -> Const a a0

Contravariant f => Contravariant (Alt f)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Alt f a -> Alt f a'

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

Contravariant f => Contravariant (Rec1 f)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Rec1 f a -> Rec1 f a'

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

(Contravariant f, Contravariant g) => Contravariant (Product f g)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Product f g a -> Product f g a'

(>$) :: b -> Product f g b -> Product f g a

(Contravariant f, Contravariant g) => Contravariant (Sum f g)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Sum f g a -> Sum f g a'

(>$) :: b -> Sum f g b -> Sum f g a

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

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> (f :*: g) a -> (f :*: g) a'

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

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

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> (f :+: g) a -> (f :+: g) a'

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

Contravariant (K1 i c :: Type -> Type)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> K1 i c a -> K1 i c a'

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

(Functor f, Contravariant g) => Contravariant (Compose f g)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Compose f g a -> Compose f g a'

(>$) :: b -> Compose f g b -> Compose f g a

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

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> (f :.: g) a -> (f :.: g) a'

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

Contravariant f => Contravariant (M1 i c f)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> M1 i c f a -> M1 i c f a'

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

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

This is an infix alias for contramap.

newtype Identity a

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

Since: base-4.8.0.0

Constructors

Identity

Fields

• runIdentity :: a

Instances

MonadFix Identity

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

mfix :: (a -> Identity a) -> Identity a

Foldable Identity

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

fold :: Monoid m => Identity m -> m

foldMap :: Monoid m => (a -> m) -> Identity a -> m

foldMap' :: Monoid m => (a -> m) -> Identity a -> m

foldr :: (a -> b -> b) -> b -> Identity a -> b

foldr' :: (a -> b -> b) -> b -> Identity a -> b

foldl :: (b -> a -> b) -> b -> Identity a -> b

foldl' :: (b -> a -> b) -> b -> Identity a -> b

foldr1 :: (a -> a -> a) -> Identity a -> a

foldl1 :: (a -> a -> a) -> Identity a -> a

toList :: Identity a -> [a]

null :: Identity a -> Bool

length :: Identity a -> Int

elem :: Eq a => a -> Identity a -> Bool

maximum :: Ord a => Identity a -> a

minimum :: Ord a => Identity a -> a

sum :: Num a => Identity a -> a

product :: Num a => Identity a -> a

Traversable Identity

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Identity a -> f (Identity b)

sequenceA :: Applicative f => Identity (f a) -> f (Identity a)

mapM :: Monad m => (a -> m b) -> Identity a -> m (Identity b)

sequence :: Monad m => Identity (m a) -> m (Identity a)

Applicative Identity

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

pure :: a -> Identity a

(<*>) :: Identity (a -> b) -> Identity a -> Identity b

liftA2 :: (a -> b -> c) -> Identity a -> Identity b -> Identity c

(*>) :: Identity a -> Identity b -> Identity b

(<*) :: Identity a -> Identity b -> Identity a

Functor Identity

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

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

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

Monad Identity

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

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

(>>) :: Identity a -> Identity b -> Identity b

return :: a -> Identity a

Generic1 Identity

Defined in Data.Functor.Identity

Associated Types

type Rep1 Identity :: k -> Type

Methods

from1 :: forall (a :: k). Identity a -> Rep1 Identity a

to1 :: forall (a :: k). Rep1 Identity a -> Identity a

IsString a => IsString (Identity a)

Since: base-4.9.0.0

Defined in Data.String

Methods

fromString :: String -> Identity a

Storable a => Storable (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

sizeOf :: Identity a -> Int

alignment :: Identity a -> Int

peekElemOff :: Ptr (Identity a) -> Int -> IO (Identity a)

pokeElemOff :: Ptr (Identity a) -> Int -> Identity a -> IO ()

peekByteOff :: Ptr b -> Int -> IO (Identity a)

pokeByteOff :: Ptr b -> Int -> Identity a -> IO ()

peek :: Ptr (Identity a) -> IO (Identity a)

poke :: Ptr (Identity a) -> Identity a -> IO ()

Monoid a => Monoid (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

mempty :: Identity a

mappend :: Identity a -> Identity a -> Identity a

mconcat :: [Identity a] -> Identity a

Semigroup a => Semigroup (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

(<>) :: Identity a -> Identity a -> Identity a

sconcat :: NonEmpty (Identity a) -> Identity a

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

Bits a => Bits (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

(.&.) :: Identity a -> Identity a -> Identity a

(.|.) :: Identity a -> Identity a -> Identity a

xor :: Identity a -> Identity a -> Identity a

complement :: Identity a -> Identity a

shift :: Identity a -> Int -> Identity a

rotate :: Identity a -> Int -> Identity a

zeroBits :: Identity a

bit :: Int -> Identity a

setBit :: Identity a -> Int -> Identity a

clearBit :: Identity a -> Int -> Identity a

complementBit :: Identity a -> Int -> Identity a

testBit :: Identity a -> Int -> Bool

bitSizeMaybe :: Identity a -> Maybe Int

bitSize :: Identity a -> Int

isSigned :: Identity a -> Bool

shiftL :: Identity a -> Int -> Identity a

unsafeShiftL :: Identity a -> Int -> Identity a

shiftR :: Identity a -> Int -> Identity a

unsafeShiftR :: Identity a -> Int -> Identity a

rotateL :: Identity a -> Int -> Identity a

rotateR :: Identity a -> Int -> Identity a

popCount :: Identity a -> Int

FiniteBits a => FiniteBits (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

finiteBitSize :: Identity a -> Int

countLeadingZeros :: Identity a -> Int

countTrailingZeros :: Identity a -> Int

Bounded a => Bounded (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

minBound :: Identity a

maxBound :: Identity a

Enum a => Enum (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

succ :: Identity a -> Identity a

pred :: Identity a -> Identity a

toEnum :: Int -> Identity a

fromEnum :: Identity a -> Int

enumFrom :: Identity a -> [Identity a]

enumFromThen :: Identity a -> Identity a -> [Identity a]

enumFromTo :: Identity a -> Identity a -> [Identity a]

enumFromThenTo :: Identity a -> Identity a -> Identity a -> [Identity a]

Floating a => Floating (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

pi :: Identity a

exp :: Identity a -> Identity a

log :: Identity a -> Identity a

sqrt :: Identity a -> Identity a

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

logBase :: Identity a -> Identity a -> Identity a

sin :: Identity a -> Identity a

cos :: Identity a -> Identity a

tan :: Identity a -> Identity a

asin :: Identity a -> Identity a

acos :: Identity a -> Identity a

atan :: Identity a -> Identity a

sinh :: Identity a -> Identity a

cosh :: Identity a -> Identity a

tanh :: Identity a -> Identity a

asinh :: Identity a -> Identity a

acosh :: Identity a -> Identity a

atanh :: Identity a -> Identity a

log1p :: Identity a -> Identity a

expm1 :: Identity a -> Identity a

log1pexp :: Identity a -> Identity a

log1mexp :: Identity a -> Identity a

RealFloat a => RealFloat (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

floatRadix :: Identity a -> Integer

floatDigits :: Identity a -> Int

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

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

encodeFloat :: Integer -> Int -> Identity a

exponent :: Identity a -> Int

significand :: Identity a -> Identity a

scaleFloat :: Int -> Identity a -> Identity a

isNaN :: Identity a -> Bool

isInfinite :: Identity a -> Bool

isDenormalized :: Identity a -> Bool

isNegativeZero :: Identity a -> Bool

isIEEE :: Identity a -> Bool

atan2 :: Identity a -> Identity a -> Identity a

Generic (Identity a)

Defined in Data.Functor.Identity

Associated Types

type Rep (Identity a) :: Type -> Type

Methods

from :: Identity a -> Rep (Identity a) x

to :: Rep (Identity a) x -> Identity a

Ix a => Ix (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

range :: (Identity a, Identity a) -> [Identity a]

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

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

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

rangeSize :: (Identity a, Identity a) -> Int

unsafeRangeSize :: (Identity a, Identity a) -> Int

Num a => Num (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

(+) :: Identity a -> Identity a -> Identity a

(-) :: Identity a -> Identity a -> Identity a

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

negate :: Identity a -> Identity a

abs :: Identity a -> Identity a

signum :: Identity a -> Identity a

fromInteger :: Integer -> Identity a

Read a => Read (Identity a)

This instance would be equivalent to the derived instances of the Identity newtype if the runIdentity field were removed

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

readsPrec :: Int -> ReadS (Identity a)

readList :: ReadS [Identity a]

readPrec :: ReadPrec (Identity a)

readListPrec :: ReadPrec [Identity a]

Fractional a => Fractional (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

(/) :: Identity a -> Identity a -> Identity a

recip :: Identity a -> Identity a

fromRational :: Rational -> Identity a

Integral a => Integral (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

quot :: Identity a -> Identity a -> Identity a

rem :: Identity a -> Identity a -> Identity a

div :: Identity a -> Identity a -> Identity a

mod :: Identity a -> Identity a -> Identity a

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

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

toInteger :: Identity a -> Integer

Real a => Real (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

toRational :: Identity a -> Rational

RealFrac a => RealFrac (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

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

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

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

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

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

Show a => Show (Identity a)

This instance would be equivalent to the derived instances of the Identity newtype if the runIdentity field were removed

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

showsPrec :: Int -> Identity a -> ShowS

show :: Identity a -> String

showList :: [Identity a] -> ShowS

Eq a => Eq (Identity a)

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

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

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

Ord a => Ord (Identity a)

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

compare :: Identity a -> Identity a -> Ordering

(<) :: Identity a -> Identity a -> Bool

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

(>) :: Identity a -> Identity a -> Bool

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

max :: Identity a -> Identity a -> Identity a

min :: Identity a -> Identity a -> Identity a

type Rep1 Identity

Since: base-4.8.0.0

Defined in Data.Functor.Identity

type Rep1 Identity = D1 ('MetaData "Identity" "Data.Functor.Identity" "base" 'True) (C1 ('MetaCons "Identity" 'PrefixI 'True) (S1 ('MetaSel ('Just "runIdentity") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

type Rep (Identity a)

Since: base-4.8.0.0

Defined in Data.Functor.Identity

type Rep (Identity a) = D1 ('MetaData "Identity" "Data.Functor.Identity" "base" 'True) (C1 ('MetaCons "Identity" 'PrefixI 'True) (S1 ('MetaSel ('Just "runIdentity") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))

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

Bits Int

Since: base-2.1

Defined in GHC.Bits

Methods

(.&.) :: Int -> Int -> Int

(.|.) :: Int -> Int -> Int

xor :: Int -> Int -> Int

complement :: Int -> Int

shift :: Int -> Int -> Int

rotate :: Int -> Int -> Int

zeroBits :: Int

bit :: Int -> Int

setBit :: Int -> Int -> Int

clearBit :: Int -> Int -> Int

complementBit :: Int -> Int -> Int

testBit :: Int -> Int -> Bool

bitSizeMaybe :: Int -> Maybe Int

bitSize :: Int -> Int

isSigned :: Int -> Bool

shiftL :: Int -> Int -> Int

unsafeShiftL :: Int -> Int -> Int

shiftR :: Int -> Int -> Int

unsafeShiftR :: Int -> Int -> Int

rotateL :: Int -> Int -> Int

rotateR :: Int -> Int -> Int

popCount :: Int -> Int

FiniteBits Int

Since: base-4.6.0.0

Defined in GHC.Bits

Methods

finiteBitSize :: Int -> Int

countLeadingZeros :: Int -> Int

countTrailingZeros :: Int -> Int

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]

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

Read Int

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Int

readList :: ReadS [Int]

readPrec :: ReadPrec Int

readListPrec :: ReadPrec [Int]

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

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

Default Int

Defined in Data.Default.Class

Methods

def :: Int

Eq Int

Defined in GHC.Classes

Methods

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

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

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

Generic1 (URec Int :: k -> Type)

Defined in GHC.Generics

Associated Types

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

Methods

from1 :: forall (a :: k0). URec Int a -> Rep1 (URec Int) a

to1 :: forall (a :: k0). Rep1 (URec Int) a -> URec Int a

Foldable (UInt :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => UInt m -> m

foldMap :: Monoid m => (a -> m) -> UInt a -> m

foldMap' :: Monoid m => (a -> m) -> UInt a -> m

foldr :: (a -> b -> b) -> b -> UInt a -> b

foldr' :: (a -> b -> b) -> b -> UInt a -> b

foldl :: (b -> a -> b) -> b -> UInt a -> b

foldl' :: (b -> a -> b) -> b -> UInt a -> b

foldr1 :: (a -> a -> a) -> UInt a -> a

foldl1 :: (a -> a -> a) -> UInt a -> a

toList :: UInt a -> [a]

null :: UInt a -> Bool

length :: UInt a -> Int

elem :: Eq a => a -> UInt a -> Bool

maximum :: Ord a => UInt a -> a

minimum :: Ord a => UInt a -> a

sum :: Num a => UInt a -> a

product :: Num a => UInt a -> a

Traversable (UInt :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UInt a -> f (UInt b)

sequenceA :: Applicative f => UInt (f a) -> f (UInt a)

mapM :: Monad m => (a -> m b) -> UInt a -> m (UInt b)

sequence :: Monad m => UInt (m a) -> m (UInt a)

Functor (URec Int :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Generic (URec Int p)

Defined in GHC.Generics

Associated Types

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

Methods

from :: URec Int p -> Rep (URec Int p) x

to :: Rep (URec Int p) x -> URec Int p

Show (URec Int p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> URec Int p -> ShowS

show :: URec Int p -> String

showList :: [URec Int p] -> ShowS

Eq (URec Int p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

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

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

Ord (URec Int p)

Since: base-4.9.0.0

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

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 -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

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

type Rep (URec Int p)

Since: base-4.9.0.0

Defined in GHC.Generics

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

data Int8

8-bit signed integer type

Instances

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

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]

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

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

Read Int8

Since: base-2.1

Defined in GHC.Int

Methods

readsPrec :: Int -> ReadS Int8

readList :: ReadS [Int8]

readPrec :: ReadPrec Int8

readListPrec :: ReadPrec [Int8]

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

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

Default Int8

Defined in Data.Default.Class

Methods

def :: Int8

Eq Int8

Since: base-2.1

Defined in GHC.Int

Methods

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

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

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

data Int16

16-bit signed integer type

Instances

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

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]

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

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

Read Int16

Since: base-2.1

Defined in GHC.Int

Methods

readsPrec :: Int -> ReadS Int16

readList :: ReadS [Int16]

readPrec :: ReadPrec Int16

readListPrec :: ReadPrec [Int16]

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

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

Default Int16

Defined in Data.Default.Class

Methods

def :: Int16

Eq Int16

Since: base-2.1

Defined in GHC.Int

Methods

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

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

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

data Int32

32-bit signed integer type

Instances

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

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]

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

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

Read Int32

Since: base-2.1

Defined in GHC.Int

Methods

readsPrec :: Int -> ReadS Int32

readList :: ReadS [Int32]

readPrec :: ReadPrec Int32

readListPrec :: ReadPrec [Int32]

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

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

Default Int32

Defined in Data.Default.Class

Methods

def :: Int32

Eq Int32

Since: base-2.1

Defined in GHC.Int

Methods

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

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

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

data Int64

64-bit signed integer type

Instances

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

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]

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

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

Read Int64

Since: base-2.1

Defined in GHC.Int

Methods

readsPrec :: Int -> ReadS Int64

readList :: ReadS [Int64]

readPrec :: ReadPrec Int64

readListPrec :: ReadPrec [Int64]

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

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

Default Int64

Defined in Data.Default.Class

Methods

def :: Int64

Eq Int64

Since: base-2.1

Defined in GHC.Int

Methods

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

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

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

data Constraint

The kind of constraints, like Show a

type Type = TYPE LiftedRep

The kind of types with lifted values. For example Int :: Type.

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

\(\mathcal{O}(\min(m,n))\). zipWith generalises zip by zipping with the function given as the first argument, instead of a tupling function.

zipWith (,) xs ys == zip xs ys
zipWith f [x1,x2,x3..] [y1,y2,y3..] == [f x1 y1, f x2 y2, f x3 y3..]

For example, zipWith (+) is applied to two lists to produce the list of corresponding sums:

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

zipWith is right-lazy:

>>> let f = undefined
>>> zipWith f [] undefined
[]

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

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

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

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

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

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

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

Users should take care to pick a return type that is wide enough to contain the full length of the list. If the width is insufficient, the overflow behaviour will depend on the (+) implementation in the selected Num instance. The following example overflows because the actual list length of 200 lies outside of the Int8 range of -128..127.

>>> genericLength [1..200] :: Int8
-56

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

In some cases, unfoldr can undo a foldr operation:

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

if the following holds:

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

A simple use of unfoldr:

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

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

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

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

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

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

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

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

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

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

Since: base-4.8.0.0

(++) :: [a] -> [a] -> [a] infixr 5

Append two lists, i.e.,

[x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn]
[x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]

If the first list is not finite, the result is the first list.

WARNING: This function takes linear time in the number of elements of the first list.

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

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

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

If one input list is shorter than the other, excess elements of the longer list are discarded, even if one of the lists is infinite:

>>> zip [1] ['a', 'b']
[(1,'a')]
>>> zip [1, 2] ['a']
[(1,'a')]
>>> zip [] [1..]
[]
>>> zip [1..] []
[]

zip is right-lazy:

>>> zip [] undefined
[]
>>> zip undefined []
*** Exception: Prelude.undefined
...

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

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

\(\mathcal{O}(n)\). map f xs is the list obtained by applying f to each element of xs, i.e.,

map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn]
map f [x1, x2, ...] == [f x1, f x2, ...]

>>> map (+1) [1, 2, 3]
[2,3,4]

uncons :: [a] -> Maybe (a, [a])

\(\mathcal{O}(1)\). Decompose a list into its head and tail.

• If the list is empty, returns Nothing.
• If the list is non-empty, returns Just (x, xs), where x is the head of the list and xs its tail.

>>> uncons []
Nothing
>>> uncons [1]
Just (1,[])
>>> uncons [1, 2, 3]
Just (1,[2,3])

Since: base-4.8.0.0

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

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

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

Note that

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

>>> scanl (+) 0 [1..4]
[0,1,3,6,10]
>>> scanl (+) 42 []
[42]
>>> scanl (-) 100 [1..4]
[100,99,97,94,90]
>>> scanl (\reversedString nextChar -> nextChar : reversedString) "foo" ['a', 'b', 'c', 'd']
["foo","afoo","bafoo","cbafoo","dcbafoo"]
>>> scanl (+) 0 [1..]
* Hangs forever *

scanl1 :: (a -> a -> a) -> [a] -> [a]

\(\mathcal{O}(n)\). scanl1 is a variant of scanl that has no starting value argument:

scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]

>>> scanl1 (+) [1..4]
[1,3,6,10]
>>> scanl1 (+) []
[]
>>> scanl1 (-) [1..4]
[1,-1,-4,-8]
>>> scanl1 (&&) [True, False, True, True]
[True,False,False,False]
>>> scanl1 (||) [False, False, True, True]
[False,False,True,True]
>>> scanl1 (+) [1..]
* Hangs forever *

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

\(\mathcal{O}(n)\). A strict version of scanl.

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

\(\mathcal{O}(n)\). scanr is the right-to-left dual of scanl. Note that the order of parameters on the accumulating function are reversed compared to scanl. Also note that

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

>>> scanr (+) 0 [1..4]
[10,9,7,4,0]
>>> scanr (+) 42 []
[42]
>>> scanr (-) 100 [1..4]
[98,-97,99,-96,100]
>>> scanr (\nextChar reversedString -> nextChar : reversedString) "foo" ['a', 'b', 'c', 'd']
["abcdfoo","bcdfoo","cdfoo","dfoo","foo"]
>>> force $ scanr (+) 0 [1..]
*** Exception: stack overflow

scanr1 :: (a -> a -> a) -> [a] -> [a]

\(\mathcal{O}(n)\). scanr1 is a variant of scanr that has no starting value argument.

>>> scanr1 (+) [1..4]
[10,9,7,4]
>>> scanr1 (+) []
[]
>>> scanr1 (-) [1..4]
[-2,3,-1,4]
>>> scanr1 (&&) [True, False, True, True]
[False,False,True,True]
>>> scanr1 (||) [True, True, False, False]
[True,True,False,False]
>>> force $ scanr1 (+) [1..]
*** Exception: stack overflow

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

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

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

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

>>> take 10 $ iterate not True
[True,False,True,False...
>>> take 10 $ iterate (+3) 42
[42,45,48,51,54,57,60,63...

repeat :: a -> [a]

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

>>> take 20 $ repeat 17
[17,17,17,17,17,17,17,17,17...

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

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

>>> replicate 0 True
[]
>>> replicate (-1) True
[]
>>> replicate 4 True
[True,True,True,True]

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

reverse :: [a] -> [a]

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

>>> reverse []
[]
>>> reverse [42]
[42]
>>> reverse [2,5,7]
[7,5,2]
>>> reverse [1..]
* Hangs forever *

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

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

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

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

>>> unzip []
([],[])
>>> unzip [(1, 'a'), (2, 'b')]
([1,2],"ab")

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

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

>>> unzip3 []
([],[],[])
>>> unzip3 [(1, 'a', True), (2, 'b', False)]
([1,2],"ab",[True,False])

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

data NonEmpty a

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

Since: base-4.9.0.0

Constructors

a :| [a] infixr 5

Instances

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

foldMap' :: Monoid m => (a -> m) -> NonEmpty a -> m

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

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

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

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

foldr1 :: (a -> a -> a) -> NonEmpty a -> a

foldl1 :: (a -> a -> a) -> NonEmpty a -> a

toList :: NonEmpty a -> [a]

null :: NonEmpty a -> Bool

length :: NonEmpty a -> Int

elem :: Eq a => a -> NonEmpty a -> Bool

maximum :: Ord a => NonEmpty a -> a

minimum :: Ord a => NonEmpty a -> a

sum :: Num a => NonEmpty a -> a

product :: Num a => NonEmpty a -> a

Traversable NonEmpty

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> NonEmpty a -> f (NonEmpty b)

sequenceA :: Applicative f => NonEmpty (f a) -> f (NonEmpty a)

mapM :: Monad m => (a -> m b) -> NonEmpty a -> m (NonEmpty b)

sequence :: Monad m => NonEmpty (m a) -> m (NonEmpty a)

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

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

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

Generic1 NonEmpty

Defined in GHC.Generics

Associated Types

type Rep1 NonEmpty :: k -> Type

Methods

from1 :: forall (a :: k). NonEmpty a -> Rep1 NonEmpty a

to1 :: forall (a :: k). Rep1 NonEmpty a -> NonEmpty a

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

Generic (NonEmpty a)

Defined in GHC.Generics

Associated Types

type Rep (NonEmpty a) :: Type -> Type

Methods

from :: NonEmpty a -> Rep (NonEmpty a) x

to :: Rep (NonEmpty a) x -> NonEmpty a

IsList (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.IsList

Associated Types

type Item (NonEmpty a)

Methods

fromList :: [Item (NonEmpty a)] -> NonEmpty a

fromListN :: Int -> [Item (NonEmpty a)] -> NonEmpty a

toList :: NonEmpty a -> [Item (NonEmpty a)]

Read a => Read (NonEmpty a)

Since: base-4.11.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (NonEmpty a)

readList :: ReadS [NonEmpty a]

readPrec :: ReadPrec (NonEmpty a)

readListPrec :: ReadPrec [NonEmpty a]

Show a => Show (NonEmpty a)

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> NonEmpty a -> ShowS

show :: NonEmpty a -> String

showList :: [NonEmpty a] -> ShowS

Eq a => Eq (NonEmpty a)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

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

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

Ord a => Ord (NonEmpty a)

Since: base-4.9.0.0

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

type Rep1 NonEmpty

Since: base-4.6.0.0

Defined in GHC.Generics

type Rep1 NonEmpty = D1 ('MetaData "NonEmpty" "GHC.Base" "base" 'False) (C1 ('MetaCons ":|" ('InfixI 'RightAssociative 5) 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1 :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 [])))

type Rep (NonEmpty a)

Since: base-4.6.0.0

Defined in GHC.Generics

type Rep (NonEmpty a) = D1 ('MetaData "NonEmpty" "GHC.Base" "base" 'False) (C1 ('MetaCons ":|" ('InfixI 'RightAssociative 5) 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [a])))

type Item (NonEmpty a)

Defined in GHC.IsList

type Item (NonEmpty a) = a

nonEmpty :: [a] -> Maybe (NonEmpty a)

nonEmpty efficiently turns a normal list into a NonEmpty stream, producing Nothing if the input is empty.

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

MonadFail Maybe

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> 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

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)

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]

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

Functor Maybe

Since: base-2.1

Defined in GHC.Base

Methods

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

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

MonadPlus Maybe

Since: base-2.1

Defined in GHC.Base

Methods

mzero :: Maybe a

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

Generic1 Maybe

Defined in GHC.Generics

Associated Types

type Rep1 Maybe :: k -> Type

Methods

from1 :: forall (a :: k). Maybe a -> Rep1 Maybe a

to1 :: forall (a :: k). Rep1 Maybe a -> Maybe a

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

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

Generic (Maybe a)

Defined in GHC.Generics

Associated Types

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

Methods

from :: Maybe a -> Rep (Maybe a) x

to :: Rep (Maybe a) x -> Maybe a

SingKind a => SingKind (Maybe a)

Since: base-4.9.0.0

Defined in GHC.Generics

Associated Types

type DemoteRep (Maybe a)

Methods

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

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Maybe a -> ShowS

show :: Maybe a -> String

showList :: [Maybe a] -> ShowS

Default (Maybe a)

Defined in Data.Default.Class

Methods

def :: Maybe a

Eq a => Eq (Maybe a)

Since: base-2.1

Defined in GHC.Maybe

Methods

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

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

Ord a => Ord (Maybe a)

Since: base-2.1

Defined in GHC.Maybe

Methods

compare :: Maybe a -> Maybe a -> Ordering

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

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

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

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

max :: Maybe a -> Maybe a -> Maybe a

min :: Maybe a -> Maybe a -> Maybe a

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 Rep1 Maybe

Since: base-4.6.0.0

Defined in GHC.Generics

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

type DemoteRep (Maybe a)

Defined in GHC.Generics

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

type Rep (Maybe a)

Since: base-4.6.0.0

Defined in GHC.Generics

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

data Sing (b :: Maybe a)

Defined in GHC.Generics

data Sing (b :: Maybe a) where

• SNothing :: forall {a}. Sing ('Nothing :: Maybe a)
• SJust :: forall {a} (a1 :: a). Sing a1 -> Sing ('Just a1)

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
""

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

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

fromMaybe :: a -> Maybe a -> a

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

maybeToList :: Maybe a -> [a]

The maybeToList function returns an empty list when given Nothing or a singleton list when given Just.

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

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]

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]

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

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

Examples

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

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

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

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

class Semigroup a => Monoid a where

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

Right identity

x <> mempty = x

Left identity

mempty <> x = x

Associativity

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

Concatenation

mconcat = foldr (<>) mempty

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

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

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

Minimal complete definition

mempty

Methods

mempty :: a

Identity of mappend

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

mappend :: a -> a -> a

An associative operation

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

mconcat :: [a] -> a

Fold a list using the monoid.

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

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

Instances

Monoid ByteString

Defined in Data.ByteString.Internal.Type

Methods

mempty :: ByteString

mappend :: ByteString -> ByteString -> ByteString

mconcat :: [ByteString] -> ByteString

Monoid ByteString

Defined in Data.ByteString.Lazy.Internal

Methods

mempty :: ByteString

mappend :: ByteString -> ByteString -> ByteString

mconcat :: [ByteString] -> ByteString

Monoid ShortByteString

Defined in Data.ByteString.Short.Internal

Methods

mempty :: ShortByteString

mappend :: ShortByteString -> ShortByteString -> ShortByteString

mconcat :: [ShortByteString] -> ShortByteString

Monoid IntSet

Defined in Data.IntSet.Internal

Methods

mempty :: IntSet

mappend :: IntSet -> IntSet -> IntSet

mconcat :: [IntSet] -> IntSet

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 :: [()] -> ()

FiniteBits a => Monoid (And a)

This constraint is arguably too strong. However, as some types (such as Natural) have undefined complement, this is the only safe choice.

Since: base-4.16

Defined in Data.Bits

Methods

mempty :: And a

mappend :: And a -> And a -> And a

mconcat :: [And a] -> And a

FiniteBits a => Monoid (Iff a)

This constraint is arguably too strong. However, as some types (such as Natural) have undefined complement, this is the only safe choice.

Since: base-4.16

Defined in Data.Bits

Methods

mempty :: Iff a

mappend :: Iff a -> Iff a -> Iff a

mconcat :: [Iff a] -> Iff a

Bits a => Monoid (Ior a)

Since: base-4.16

Defined in Data.Bits

Methods

mempty :: Ior a

mappend :: Ior a -> Ior a -> Ior a

mconcat :: [Ior a] -> Ior a

Bits a => Monoid (Xor a)

Since: base-4.16

Defined in Data.Bits

Methods

mempty :: Xor a

mappend :: Xor a -> Xor a -> Xor a

mconcat :: [Xor a] -> Xor a

Monoid (Comparison a)

mempty on comparisons always returns EQ. Without newtypes this equals pure (pure EQ).

mempty :: Comparison a
mempty = Comparison _ _ -> EQ

Defined in Data.Functor.Contravariant

Methods

mempty :: Comparison a

mappend :: Comparison a -> Comparison a -> Comparison a

mconcat :: [Comparison a] -> Comparison a

Monoid (Equivalence a)

mempty on equivalences always returns True. Without newtypes this equals pure (pure True).

mempty :: Equivalence a
mempty = Equivalence _ _ -> True

Defined in Data.Functor.Contravariant

Methods

mempty :: Equivalence a

mappend :: Equivalence a -> Equivalence a -> Equivalence a

mconcat :: [Equivalence a] -> Equivalence a

Monoid (Predicate a)

mempty on predicates always returns True. Without newtypes this equals pure True.

mempty :: Predicate a
mempty = _ -> True

Defined in Data.Functor.Contravariant

Methods

mempty :: Predicate a

mappend :: Predicate a -> Predicate a -> Predicate a

mconcat :: [Predicate a] -> Predicate a

Monoid a => Monoid (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

mempty :: Identity a

mappend :: Identity a -> Identity a -> Identity a

mconcat :: [Identity a] -> Identity a

Monoid (First a)

Since: base-2.1

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 (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, 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

(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

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

(Generic a, Monoid (Rep a ())) => Monoid (Generically a)

Since: base-4.17.0.0

Defined in GHC.Generics

Methods

mempty :: Generically a

mappend :: Generically a -> Generically a -> Generically a

mconcat :: [Generically a] -> Generically a

Monoid p => Monoid (Par1 p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

mempty :: Par1 p

mappend :: Par1 p -> Par1 p -> Par1 p

mconcat :: [Par1 p] -> Par1 p

Monoid (IntMap a)

Defined in Data.IntMap.Internal

Methods

mempty :: IntMap a

mappend :: IntMap a -> IntMap a -> IntMap a

mconcat :: [IntMap a] -> IntMap a

Monoid (Seq a)

Defined in Data.Sequence.Internal

Methods

mempty :: Seq a

mappend :: Seq a -> Seq a -> Seq a

mconcat :: [Seq a] -> Seq 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

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 (DList a)

Defined in Data.DList.Internal

Methods

mempty :: DList a

mappend :: DList a -> DList a -> DList a

mconcat :: [DList a] -> DList 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

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 (a)

Since: base-4.15

Defined in GHC.Base

Methods

mempty :: (a)

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

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

Monoid [a]

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: [a]

mappend :: [a] -> [a] -> [a]

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

Monoid a => Monoid (Op a b)

mempty @(Op a b) without newtypes is mempty @(b->a) = _ -> mempty.

mempty :: Op a b
mempty = Op _ -> mempty

Defined in Data.Functor.Contravariant

Methods

mempty :: Op a b

mappend :: Op a b -> Op a b -> Op a b

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

Monoid (Proxy s)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

mempty :: Proxy s

mappend :: Proxy s -> Proxy s -> Proxy s

mconcat :: [Proxy s] -> Proxy s

Monoid (U1 p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

mempty :: U1 p

mappend :: U1 p -> U1 p -> U1 p

mconcat :: [U1 p] -> U1 p

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 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 a => Monoid (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

mempty :: Const a b

mappend :: Const a b -> Const a b -> Const a b

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

(Applicative f, Monoid a) => Monoid (Ap f a)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

mempty :: Ap f a

mappend :: Ap f a -> Ap f a -> Ap f a

mconcat :: [Ap f a] -> Ap f a

Monoid (f p) => Monoid (Rec1 f p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

mempty :: Rec1 f p

mappend :: Rec1 f p -> Rec1 f p -> Rec1 f p

mconcat :: [Rec1 f p] -> Rec1 f p

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

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: (a, b, c)

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

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

(Monoid (f a), Monoid (g a)) => Monoid (Product f g a)

Since: base-4.16.0.0

Defined in Data.Functor.Product

Methods

mempty :: Product f g a

mappend :: Product f g a -> Product f g a -> Product f g a

mconcat :: [Product f g a] -> Product f g a

(Monoid (f p), Monoid (g p)) => Monoid ((f :*: g) p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

mempty :: (f :*: g) p

mappend :: (f :*: g) p -> (f :*: g) p -> (f :*: g) p

mconcat :: [(f :*: g) p] -> (f :*: g) p

Monoid c => Monoid (K1 i c p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

mempty :: K1 i c p

mappend :: K1 i c p -> K1 i c p -> K1 i c p

mconcat :: [K1 i c p] -> K1 i c p

(Monoid 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 (f (g a)) => Monoid (Compose f g a)

Since: base-4.16.0.0

Defined in Data.Functor.Compose

Methods

mempty :: Compose f g a

mappend :: Compose f g a -> Compose f g a -> Compose f g a

mconcat :: [Compose f g a] -> Compose f g a

Monoid (f (g p)) => Monoid ((f :.: g) p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

mempty :: (f :.: g) p

mappend :: (f :.: g) p -> (f :.: g) p -> (f :.: g) p

mconcat :: [(f :.: g) p] -> (f :.: g) p

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

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

mempty :: M1 i c f p

mappend :: M1 i c f p -> M1 i c f p -> M1 i c f p

mconcat :: [M1 i c f p] -> M1 i c f p

(Monoid 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)

data Ordering

Constructors

LT

EQ

GT

Instances

Monoid Ordering

Since: base-2.1

Defined in GHC.Base

Methods

mempty :: Ordering

mappend :: Ordering -> Ordering -> Ordering

mconcat :: [Ordering] -> 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

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]

Generic Ordering

Defined in GHC.Generics

Associated Types

type Rep Ordering :: Type -> Type

Methods

from :: Ordering -> Rep Ordering x

to :: Rep Ordering x -> 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

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Ordering -> ShowS

show :: Ordering -> String

showList :: [Ordering] -> ShowS

Default Ordering

Defined in Data.Default.Class

Methods

def :: 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

type Rep Ordering

Since: base-4.6.0.0

Defined in GHC.Generics

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

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.

Ord, as defined by the Haskell report, implements a total order and has the following properties:

Comparability

x <= y || y <= x = True

Transitivity

if x <= y && y <= z = True, then x <= z = True

Reflexivity

x <= x = True

Antisymmetry

if x <= y && y <= x = True, then x == y = True

The following operator interactions are expected to hold:

1. x >= y = y <= x
2. x < y = x <= y && x /= y
3. x > y = y < x
4. x < y = compare x y == LT
5. x > y = compare x y == GT
6. x == y = compare x y == EQ
7. min x y == if x <= y then x else y = True
8. max x y == if x >= y then x else y = True

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

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

Minimal complete definition

compare | (<=)

Methods

compare :: a -> a -> Ordering

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

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

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

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

max :: a -> a -> a

min :: a -> a -> a

Instances

Ord SomeTypeRep

Defined in Data.Typeable.Internal

Methods

compare :: SomeTypeRep -> SomeTypeRep -> Ordering

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

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

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

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

max :: SomeTypeRep -> SomeTypeRep -> SomeTypeRep

min :: SomeTypeRep -> SomeTypeRep -> SomeTypeRep

Ord Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

compare :: Void -> Void -> Ordering

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

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

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

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

max :: Void -> Void -> Void

min :: Void -> Void -> Void

Ord ArithException

Since: base-3.0

Defined in GHC.Exception.Type

Methods

compare :: ArithException -> ArithException -> Ordering

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

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

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

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

max :: ArithException -> ArithException -> ArithException

min :: ArithException -> ArithException -> ArithException

Ord Associativity

Since: base-4.6.0.0

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 DecidedStrictness

Since: base-4.9.0.0

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 Fixity

Since: base-4.6.0.0

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 SourceStrictness

Since: base-4.9.0.0

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 SourceUnpackedness

Since: base-4.9.0.0

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 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 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 SomeChar

Defined in GHC.TypeLits

Methods

compare :: SomeChar -> SomeChar -> Ordering

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

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

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

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

max :: SomeChar -> SomeChar -> SomeChar

min :: SomeChar -> SomeChar -> SomeChar

Ord SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

compare :: SomeSymbol -> SomeSymbol -> Ordering

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

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

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

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

max :: SomeSymbol -> SomeSymbol -> SomeSymbol

min :: SomeSymbol -> SomeSymbol -> SomeSymbol

Ord SomeNat

Since: base-4.7.0.0

Defined in GHC.TypeNats

Methods

compare :: SomeNat -> SomeNat -> Ordering

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

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

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

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

max :: SomeNat -> SomeNat -> SomeNat

min :: SomeNat -> SomeNat -> SomeNat

Ord Word16

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word16 -> Word16 -> Ordering

(<) :: Word16 -> Word16 -> Bool

(<=) :: Word16 -> Word16 -> Bool

(>) :: Word16 -> Word16 -> Bool

(>=) :: Word16 -> Word16 -> Bool

max :: Word16 -> Word16 -> Word16

min :: Word16 -> Word16 -> Word16

Ord Word32

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word32 -> Word32 -> Ordering

(<) :: Word32 -> Word32 -> Bool

(<=) :: Word32 -> Word32 -> Bool

(>) :: Word32 -> Word32 -> Bool

(>=) :: Word32 -> Word32 -> Bool

max :: Word32 -> Word32 -> Word32

min :: Word32 -> Word32 -> Word32

Ord Word64

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word64 -> Word64 -> Ordering

(<) :: Word64 -> Word64 -> Bool

(<=) :: Word64 -> Word64 -> Bool

(>) :: Word64 -> Word64 -> Bool

(>=) :: Word64 -> Word64 -> Bool

max :: Word64 -> Word64 -> Word64

min :: Word64 -> Word64 -> Word64

Ord Word8

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word8 -> Word8 -> Ordering

(<) :: Word8 -> Word8 -> Bool

(<=) :: Word8 -> Word8 -> Bool

(>) :: Word8 -> Word8 -> Bool

(>=) :: Word8 -> Word8 -> Bool

max :: Word8 -> Word8 -> Word8

min :: Word8 -> Word8 -> Word8

Ord ByteString

Defined in Data.ByteString.Internal.Type

Methods

compare :: ByteString -> ByteString -> Ordering

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

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

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

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

max :: ByteString -> ByteString -> ByteString

min :: ByteString -> ByteString -> ByteString

Ord ByteString

Defined in Data.ByteString.Lazy.Internal

Methods

compare :: ByteString -> ByteString -> Ordering

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

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

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

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

max :: ByteString -> ByteString -> ByteString

min :: ByteString -> ByteString -> ByteString

Ord ShortByteString

Defined in Data.ByteString.Short.Internal

Methods

compare :: ShortByteString -> ShortByteString -> Ordering

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

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

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

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

max :: ShortByteString -> ShortByteString -> ShortByteString

min :: ShortByteString -> ShortByteString -> ShortByteString

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 BigNat

Defined in GHC.Num.BigNat

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 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 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 Integer

Defined in GHC.Num.Integer

Methods

compare :: Integer -> Integer -> Ordering

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

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

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

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

max :: Integer -> Integer -> Integer

min :: Integer -> Integer -> Integer

Ord Natural

Defined in GHC.Num.Natural

Methods

compare :: Natural -> Natural -> Ordering

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

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

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

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

max :: Natural -> Natural -> Natural

min :: Natural -> Natural -> Natural

Ord ()

Defined in GHC.Classes

Methods

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

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

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

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

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

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

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

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

Note that due to the presence of NaN, Double's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Double)
False

Also note that, due to the same, Ord's operator interactions are not respected by Double's instance:

>>> (0/0 :: Double) > 1
False
>>> compare (0/0 :: Double) 1
GT

Defined in GHC.Classes

Methods

compare :: Double -> Double -> Ordering

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

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

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

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

max :: Double -> Double -> Double

min :: Double -> Double -> Double

Ord Float

Note that due to the presence of NaN, Float's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Float)
False

Also note that, due to the same, Ord's operator interactions are not respected by Float's instance:

>>> (0/0 :: Float) > 1
False
>>> compare (0/0 :: Float) 1
GT

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 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 a => Ord (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

compare :: ZipList a -> ZipList a -> Ordering

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

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

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

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

max :: ZipList a -> ZipList a -> ZipList a

min :: ZipList a -> ZipList a -> ZipList a

Ord a => Ord (Identity a)

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

compare :: Identity a -> Identity a -> Ordering

(<) :: Identity a -> Identity a -> Bool

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

(>) :: Identity a -> Identity a -> Bool

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

max :: Identity a -> Identity a -> Identity a

min :: Identity a -> Identity a -> Identity a

Ord a => Ord (First a)

Since: base-2.1

Defined in Data.Monoid

Methods

compare :: First a -> First a -> Ordering

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

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

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

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

max :: First a -> First a -> First a

min :: First a -> First a -> First a

Ord a => Ord (Last a)

Since: base-2.1

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 (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 (First a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

compare :: First a -> First a -> Ordering

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

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

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

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

max :: First a -> First a -> First a

min :: First a -> First a -> First a

Ord a => Ord (Last a)

Since: base-4.9.0.0

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 a => Ord (Max a)

Since: base-4.9.0.0

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 (Min a)

Since: base-4.9.0.0

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 m => Ord (WrappedMonoid m)

Since: base-4.9.0.0

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 p => Ord (Par1 p)

Since: base-4.7.0.0

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

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 a => Ord (IntMap a)

Defined in Data.IntMap.Internal

Methods

compare :: IntMap a -> IntMap a -> Ordering

(<) :: IntMap a -> IntMap a -> Bool

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

(>) :: IntMap a -> IntMap a -> Bool

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

max :: IntMap a -> IntMap a -> IntMap a

min :: IntMap a -> IntMap a -> IntMap a

Ord a => Ord (Seq a)

Defined in Data.Sequence.Internal

Methods

compare :: Seq a -> Seq a -> Ordering

(<) :: Seq a -> Seq a -> Bool

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

(>) :: Seq a -> Seq a -> Bool

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

max :: Seq a -> Seq a -> Seq a

min :: Seq a -> Seq a -> Seq a

Ord a => Ord (ViewL a)

Defined in Data.Sequence.Internal

Methods

compare :: ViewL a -> ViewL a -> Ordering

(<) :: ViewL a -> ViewL a -> Bool

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

(>) :: ViewL a -> ViewL a -> Bool

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

max :: ViewL a -> ViewL a -> ViewL a

min :: ViewL a -> ViewL a -> ViewL a

Ord a => Ord (ViewR a)

Defined in Data.Sequence.Internal

Methods

compare :: ViewR a -> ViewR a -> Ordering

(<) :: ViewR a -> ViewR a -> Bool

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

(>) :: ViewR a -> ViewR a -> Bool

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

max :: ViewR a -> ViewR a -> ViewR a

min :: ViewR a -> ViewR a -> ViewR a

Ord a => Ord (Intersection a)

Defined in Data.Set.Internal

Methods

compare :: Intersection a -> Intersection a -> Ordering

(<) :: Intersection a -> Intersection a -> Bool

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

(>) :: Intersection a -> Intersection a -> Bool

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

max :: Intersection a -> Intersection a -> Intersection a

min :: Intersection a -> Intersection a -> Intersection 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 (DList a)

Defined in Data.DList.Internal

Methods

compare :: DList a -> DList a -> Ordering

(<) :: DList a -> DList a -> Bool

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

(>) :: DList a -> DList a -> Bool

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

max :: DList a -> DList a -> DList a

min :: DList a -> DList a -> DList a

Ord a => Ord (NonEmpty a)

Since: base-4.9.0.0

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 (Maybe a)

Since: base-2.1

Defined in GHC.Maybe

Methods

compare :: Maybe a -> Maybe a -> Ordering

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

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

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

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

max :: Maybe a -> Maybe a -> Maybe a

min :: Maybe a -> Maybe a -> Maybe a

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 [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 b) => Ord (Either a b)

Since: base-2.1

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 (Fixed a)

Since: base-2.1

Defined in Data.Fixed

Methods

compare :: Fixed a -> Fixed a -> Ordering

(<) :: Fixed a -> Fixed a -> Bool

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

(>) :: Fixed a -> Fixed a -> Bool

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

max :: Fixed a -> Fixed a -> Fixed a

min :: Fixed a -> Fixed a -> Fixed a

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 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 (TypeRep a)

Since: base-4.4.0.0

Defined in Data.Typeable.Internal

Methods

compare :: TypeRep a -> TypeRep a -> Ordering

(<) :: TypeRep a -> TypeRep a -> Bool

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

(>) :: TypeRep a -> TypeRep a -> Bool

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

max :: TypeRep a -> TypeRep a -> TypeRep a

min :: TypeRep a -> TypeRep a -> TypeRep a

Ord (U1 p)

Since: base-4.7.0.0

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 (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 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 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)

Ord a => Ord (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

compare :: Const a b -> Const a b -> Ordering

(<) :: Const a b -> Const a b -> Bool

(<=) :: Const a b -> Const a b -> Bool

(>) :: Const a b -> Const a b -> Bool

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

max :: Const a b -> Const a b -> Const a b

min :: Const a b -> Const a b -> Const a b

Ord (f a) => Ord (Ap f a)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

compare :: Ap f a -> Ap f a -> Ordering

(<) :: Ap f a -> Ap f a -> Bool

(<=) :: Ap f a -> Ap f a -> Bool

(>) :: Ap f a -> Ap f a -> Bool

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

max :: Ap f a -> Ap f a -> Ap f a

min :: Ap f a -> Ap f a -> Ap f a

Ord (a :~: b)

Since: base-4.7.0.0

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 (Rec1 f p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

compare :: Rec1 f p -> Rec1 f p -> Ordering

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

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

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

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

max :: Rec1 f p -> Rec1 f p -> Rec1 f p

min :: Rec1 f p -> Rec1 f p -> Rec1 f p

Ord (URec (Ptr ()) p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

compare :: URec (Ptr ()) p -> URec (Ptr ()) p -> Ordering

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

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

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

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

max :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p

min :: URec (Ptr ()) p -> URec (Ptr ()) p -> URec (Ptr ()) p

Ord (URec Char p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

compare :: URec Char p -> URec Char p -> Ordering

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

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

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

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

max :: URec Char p -> URec Char p -> URec Char p

min :: URec Char p -> URec Char p -> URec Char p

Ord (URec Double p)

Since: base-4.9.0.0

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)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

compare :: URec Int p -> URec Int p -> Ordering

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

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

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

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

max :: URec Int p -> URec Int p -> URec Int p

min :: URec Int p -> URec Int p -> URec Int p

Ord (URec Word p)

Since: base-4.9.0.0

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)

(Ord1 f, Ord1 g, Ord a) => Ord (Product f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Product

Methods

compare :: Product f g a -> Product f g a -> Ordering

(<) :: Product f g a -> Product f g a -> Bool

(<=) :: Product f g a -> Product f g a -> Bool

(>) :: Product f g a -> Product f g a -> Bool

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

max :: Product f g a -> Product f g a -> Product f g a

min :: Product f g a -> Product f g a -> Product f g a

(Ord1 f, Ord1 g, Ord a) => Ord (Sum f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Sum

Methods

compare :: Sum f g a -> Sum f g a -> Ordering

(<) :: Sum f g a -> Sum f g a -> Bool

(<=) :: Sum f g a -> Sum f g a -> Bool

(>) :: Sum f g a -> Sum f g a -> Bool

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

max :: Sum f g a -> Sum f g a -> Sum f g a

min :: Sum f g a -> Sum f g a -> Sum f g a

Ord (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 (g p)) => Ord ((f :*: g) p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

compare :: (f :*: g) p -> (f :*: g) p -> Ordering

(<) :: (f :*: g) p -> (f :*: g) p -> Bool

(<=) :: (f :*: g) p -> (f :*: g) p -> Bool

(>) :: (f :*: g) p -> (f :*: g) p -> Bool

(>=) :: (f :*: g) p -> (f :*: g) p -> Bool

max :: (f :*: g) p -> (f :*: g) p -> (f :*: g) p

min :: (f :*: g) p -> (f :*: g) p -> (f :*: g) p

(Ord (f p), Ord (g p)) => Ord ((f :+: g) p)

Since: base-4.7.0.0

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 c => Ord (K1 i c p)

Since: base-4.7.0.0

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 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)

(Ord1 f, Ord1 g, Ord a) => Ord (Compose f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

compare :: Compose f g a -> Compose f g a -> Ordering

(<) :: Compose f g a -> Compose f g a -> Bool

(<=) :: Compose f g a -> Compose f g a -> Bool

(>) :: Compose f g a -> Compose f g a -> Bool

(>=) :: Compose f g a -> Compose f g a -> Bool

max :: Compose f g a -> Compose f g a -> Compose f g a

min :: Compose f g a -> Compose f g a -> Compose f g a

Ord (f (g p)) => Ord ((f :.: g) p)

Since: base-4.7.0.0

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 (M1 i c f p)

Since: base-4.7.0.0

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 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)

newtype Down a

The Down type allows you to reverse sort order conveniently. A value of type Down a contains a value of type a (represented as Down a).

If a has an Ord instance associated with it then comparing two values thus wrapped will give you the opposite of their normal sort order. This is particularly useful when sorting in generalised list comprehensions, as in: then sortWith by Down x.

>>> compare True False
GT

>>> compare (Down True) (Down False)
LT

If a has a Bounded instance then the wrapped instance also respects the reversed ordering by exchanging the values of minBound and maxBound.

>>> minBound :: Int
-9223372036854775808

>>> minBound :: Down Int
Down 9223372036854775807

All other instances of Down a behave as they do for a.

Since: base-4.6.0.0

Constructors

Down

Fields

• getDown :: a

  Since: base-4.14.0.0

Instances

Foldable Down

Since: base-4.12.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => Down m -> m

foldMap :: Monoid m => (a -> m) -> Down a -> m

foldMap' :: Monoid m => (a -> m) -> Down a -> m

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

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

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

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

foldr1 :: (a -> a -> a) -> Down a -> a

foldl1 :: (a -> a -> a) -> Down a -> a

toList :: Down a -> [a]

null :: Down a -> Bool

length :: Down a -> Int

elem :: Eq a => a -> Down a -> Bool

maximum :: Ord a => Down a -> a

minimum :: Ord a => Down a -> a

sum :: Num a => Down a -> a

product :: Num a => Down a -> a

Traversable Down

Since: base-4.12.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Down a -> f (Down b)

sequenceA :: Applicative f => Down (f a) -> f (Down a)

mapM :: Monad m => (a -> m b) -> Down a -> m (Down b)

sequence :: Monad m => Down (m a) -> m (Down a)

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

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

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

Generic1 Down

Defined in GHC.Generics

Associated Types

type Rep1 Down :: k -> Type

Methods

from1 :: forall (a :: k). Down a -> Rep1 Down a

to1 :: forall (a :: k). Rep1 Down a -> Down a

Storable a => Storable (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

sizeOf :: Down a -> Int

alignment :: Down a -> Int

peekElemOff :: Ptr (Down a) -> Int -> IO (Down a)

pokeElemOff :: Ptr (Down a) -> Int -> Down a -> IO ()

peekByteOff :: Ptr b -> Int -> IO (Down a)

pokeByteOff :: Ptr b -> Int -> Down a -> IO ()

peek :: Ptr (Down a) -> IO (Down a)

poke :: Ptr (Down a) -> Down a -> IO ()

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

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

Bits a => Bits (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

(.&.) :: Down a -> Down a -> Down a

(.|.) :: Down a -> Down a -> Down a

xor :: Down a -> Down a -> Down a

complement :: Down a -> Down a

shift :: Down a -> Int -> Down a

rotate :: Down a -> Int -> Down a

zeroBits :: Down a

bit :: Int -> Down a

setBit :: Down a -> Int -> Down a

clearBit :: Down a -> Int -> Down a

complementBit :: Down a -> Int -> Down a

testBit :: Down a -> Int -> Bool

bitSizeMaybe :: Down a -> Maybe Int

bitSize :: Down a -> Int

isSigned :: Down a -> Bool

shiftL :: Down a -> Int -> Down a

unsafeShiftL :: Down a -> Int -> Down a

shiftR :: Down a -> Int -> Down a

unsafeShiftR :: Down a -> Int -> Down a

rotateL :: Down a -> Int -> Down a

rotateR :: Down a -> Int -> Down a

popCount :: Down a -> Int

FiniteBits a => FiniteBits (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

finiteBitSize :: Down a -> Int

countLeadingZeros :: Down a -> Int

countTrailingZeros :: Down a -> Int

Bounded a => Bounded (Down a)

Swaps minBound and maxBound of the underlying type.

Since: base-4.14.0.0

Defined in Data.Ord

Methods

minBound :: Down a

maxBound :: Down a

Floating a => Floating (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

pi :: Down a

exp :: Down a -> Down a

log :: Down a -> Down a

sqrt :: Down a -> Down a

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

logBase :: Down a -> Down a -> Down a

sin :: Down a -> Down a

cos :: Down a -> Down a

tan :: Down a -> Down a

asin :: Down a -> Down a

acos :: Down a -> Down a

atan :: Down a -> Down a

sinh :: Down a -> Down a

cosh :: Down a -> Down a

tanh :: Down a -> Down a

asinh :: Down a -> Down a

acosh :: Down a -> Down a

atanh :: Down a -> Down a

log1p :: Down a -> Down a

expm1 :: Down a -> Down a

log1pexp :: Down a -> Down a

log1mexp :: Down a -> Down a

RealFloat a => RealFloat (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

floatRadix :: Down a -> Integer

floatDigits :: Down a -> Int

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

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

encodeFloat :: Integer -> Int -> Down a

exponent :: Down a -> Int

significand :: Down a -> Down a

scaleFloat :: Int -> Down a -> Down a

isNaN :: Down a -> Bool

isInfinite :: Down a -> Bool

isDenormalized :: Down a -> Bool

isNegativeZero :: Down a -> Bool

isIEEE :: Down a -> Bool

atan2 :: Down a -> Down a -> Down a

Generic (Down a)

Defined in GHC.Generics

Associated Types

type Rep (Down a) :: Type -> Type

Methods

from :: Down a -> Rep (Down a) x

to :: Rep (Down a) x -> Down a

Ix a => Ix (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

range :: (Down a, Down a) -> [Down a]

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

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

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

rangeSize :: (Down a, Down a) -> Int

unsafeRangeSize :: (Down a, Down a) -> Int

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

Read a => Read (Down a)

This instance would be equivalent to the derived instances of the Down newtype if the getDown field were removed

Since: base-4.7.0.0

Defined in Data.Ord

Methods

readsPrec :: Int -> ReadS (Down a)

readList :: ReadS [Down a]

readPrec :: ReadPrec (Down a)

readListPrec :: ReadPrec [Down a]

Fractional a => Fractional (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

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

recip :: Down a -> Down a

fromRational :: Rational -> Down a

Real a => Real (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

toRational :: Down a -> Rational

RealFrac a => RealFrac (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

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

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

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

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

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

Show a => Show (Down a)

This instance would be equivalent to the derived instances of the Down newtype if the getDown field were removed

Since: base-4.7.0.0

Defined in Data.Ord

Methods

showsPrec :: Int -> Down a -> ShowS

show :: Down a -> String

showList :: [Down a] -> ShowS

Eq a => Eq (Down a)

Since: base-4.6.0.0

Defined in Data.Ord

Methods

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

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

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

type Rep1 Down

Since: base-4.12.0.0

Defined in GHC.Generics

type Rep1 Down = D1 ('MetaData "Down" "Data.Ord" "base" 'True) (C1 ('MetaCons "Down" 'PrefixI 'True) (S1 ('MetaSel ('Just "getDown") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))

type Rep (Down a)

Since: base-4.12.0.0

Defined in GHC.Generics

type Rep (Down a) = D1 ('MetaData "Down" "Data.Ord" "base" 'True) (C1 ('MetaCons "Down" 'PrefixI 'True) (S1 ('MetaSel ('Just "getDown") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))

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

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

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

  ... sortBy (comparing fst) ...

data Proxy (t :: k)

Proxy is a type that holds no data, but has a phantom parameter of arbitrary type (or even kind). Its use is to provide type information, even though there is no value available of that type (or it may be too costly to create one).

Historically, Proxy :: Proxy a is a safer alternative to the undefined :: a idiom.

>>> Proxy :: Proxy (Void, Int -> Int)
Proxy

Proxy can even hold types of higher kinds,

>>> Proxy :: Proxy Either
Proxy

>>> Proxy :: Proxy Functor
Proxy

>>> Proxy :: Proxy complicatedStructure
Proxy

Constructors

Proxy

Instances

Generic1 (Proxy :: k -> Type)

Defined in GHC.Generics

Associated Types

type Rep1 Proxy :: k -> Type

Methods

from1 :: forall (a :: k0). Proxy a -> Rep1 Proxy a

to1 :: forall (a :: k0). Rep1 Proxy a -> Proxy a

Foldable (Proxy :: Type -> Type)

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

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

Contravariant (Proxy :: Type -> Type)

Defined in Data.Functor.Contravariant

Methods

contramap :: (a' -> a) -> Proxy a -> Proxy a'

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

Traversable (Proxy :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Proxy a -> f (Proxy b)

sequenceA :: Applicative f => Proxy (f a) -> f (Proxy a)

mapM :: Monad m => (a -> m b) -> Proxy a -> m (Proxy b)

sequence :: Monad m => Proxy (m a) -> m (Proxy a)

Alternative (Proxy :: Type -> Type)

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]

Applicative (Proxy :: Type -> Type)

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

Functor (Proxy :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

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

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

Monad (Proxy :: Type -> Type)

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

MonadPlus (Proxy :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Proxy

Methods

mzero :: Proxy a

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

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

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

Bounded (Proxy t)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

minBound :: Proxy t

maxBound :: Proxy t

Enum (Proxy s)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

succ :: Proxy s -> Proxy s

pred :: Proxy s -> Proxy s

toEnum :: Int -> Proxy s

fromEnum :: Proxy s -> Int

enumFrom :: Proxy s -> [Proxy s]

enumFromThen :: Proxy s -> Proxy s -> [Proxy s]

enumFromTo :: Proxy s -> Proxy s -> [Proxy s]

enumFromThenTo :: Proxy s -> Proxy s -> Proxy s -> [Proxy s]

Generic (Proxy t)

Defined in GHC.Generics

Associated Types

type Rep (Proxy t) :: Type -> Type

Methods

from :: Proxy t -> Rep (Proxy t) x

to :: Rep (Proxy t) x -> Proxy t

Ix (Proxy s)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

range :: (Proxy s, Proxy s) -> [Proxy s]

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

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

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

rangeSize :: (Proxy s, Proxy s) -> Int

unsafeRangeSize :: (Proxy s, Proxy s) -> Int

Read (Proxy t)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

readsPrec :: Int -> ReadS (Proxy t)

readList :: ReadS [Proxy t]

readPrec :: ReadPrec (Proxy t)

readListPrec :: ReadPrec [Proxy t]

Show (Proxy s)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

showsPrec :: Int -> Proxy s -> ShowS

show :: Proxy s -> String

showList :: [Proxy s] -> ShowS

Eq (Proxy s)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

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

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

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

type Rep1 (Proxy :: k -> Type)

Since: base-4.6.0.0

Defined in GHC.Generics

type Rep1 (Proxy :: k -> Type) = D1 ('MetaData "Proxy" "Data.Proxy" "base" 'False) (C1 ('MetaCons "Proxy" 'PrefixI 'False) (U1 :: k -> Type))

type Rep (Proxy t)

Since: base-4.6.0.0

Defined in GHC.Generics

type Rep (Proxy t) = D1 ('MetaData "Proxy" "Data.Proxy" "base" 'False) (C1 ('MetaCons "Proxy" 'PrefixI 'False) (U1 :: Type -> Type))

class Semigroup a where

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

Instances should satisfy the following:

Associativity

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

Since: base-4.9.0.0

Minimal complete definition

(<>)

Methods

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

An associative operation.

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

sconcat :: NonEmpty a -> a

Reduce a non-empty list with <>

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

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

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

Repeat a value n times.

Given that this works on a Semigroup it is allowed to fail if you request 0 or fewer repetitions, and the default definition will do so.

By making this a member of the class, idempotent semigroups and monoids can upgrade this to execute in \(\mathcal{O}(1)\) by picking stimes = stimesIdempotent or stimes = stimesIdempotentMonoid respectively.

>>> stimes 4 [1]
[1,1,1,1]

Instances

Semigroup Void

Since: base-4.9.0.0

Defined in Data.Void

Methods

(<>) :: Void -> Void -> Void

sconcat :: NonEmpty Void -> Void

stimes :: Integral b => b -> Void -> Void

Semigroup ByteString

Defined in Data.ByteString.Internal.Type

Methods

(<>) :: ByteString -> ByteString -> ByteString

sconcat :: NonEmpty ByteString -> ByteString

stimes :: Integral b => b -> ByteString -> ByteString

Semigroup ByteString

Defined in Data.ByteString.Lazy.Internal

Methods

(<>) :: ByteString -> ByteString -> ByteString

sconcat :: NonEmpty ByteString -> ByteString

stimes :: Integral b => b -> ByteString -> ByteString

Semigroup ShortByteString

Defined in Data.ByteString.Short.Internal

Methods

(<>) :: ShortByteString -> ShortByteString -> ShortByteString

sconcat :: NonEmpty ShortByteString -> ShortByteString

stimes :: Integral b => b -> ShortByteString -> ShortByteString

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 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 -> () -> ()

Bits a => Semigroup (And a)

Since: base-4.16

Defined in Data.Bits

Methods

(<>) :: And a -> And a -> And a

sconcat :: NonEmpty (And a) -> And a

stimes :: Integral b => b -> And a -> And a

FiniteBits a => Semigroup (Iff a)

This constraint is arguably too strong. However, as some types (such as Natural) have undefined complement, this is the only safe choice.

Since: base-4.16

Defined in Data.Bits

Methods

(<>) :: Iff a -> Iff a -> Iff a

sconcat :: NonEmpty (Iff a) -> Iff a

stimes :: Integral b => b -> Iff a -> Iff a

Bits a => Semigroup (Ior a)

Since: base-4.16

Defined in Data.Bits

Methods

(<>) :: Ior a -> Ior a -> Ior a

sconcat :: NonEmpty (Ior a) -> Ior a

stimes :: Integral b => b -> Ior a -> Ior a

Bits a => Semigroup (Xor a)

Since: base-4.16

Defined in Data.Bits

Methods

(<>) :: Xor a -> Xor a -> Xor a

sconcat :: NonEmpty (Xor a) -> Xor a

stimes :: Integral b => b -> Xor a -> Xor a

Semigroup (Comparison a)

(<>) on comparisons combines results with (<>) @Ordering. Without newtypes this equals liftA2 (liftA2 (<>)).

(<>) :: Comparison a -> Comparison a -> Comparison a
Comparison cmp <> Comparison cmp' = Comparison a a' ->
  cmp a a' <> cmp a a'

Defined in Data.Functor.Contravariant

Methods

(<>) :: Comparison a -> Comparison a -> Comparison a

sconcat :: NonEmpty (Comparison a) -> Comparison a

stimes :: Integral b => b -> Comparison a -> Comparison a

Semigroup (Equivalence a)

(<>) on equivalences uses logical conjunction (&&) on the results. Without newtypes this equals liftA2 (liftA2 (&&)).

(<>) :: Equivalence a -> Equivalence a -> Equivalence a
Equivalence equiv <> Equivalence equiv' = Equivalence a b ->
  equiv a b && equiv' a b

Defined in Data.Functor.Contravariant

Methods

(<>) :: Equivalence a -> Equivalence a -> Equivalence a

sconcat :: NonEmpty (Equivalence a) -> Equivalence a

stimes :: Integral b => b -> Equivalence a -> Equivalence a

Semigroup (Predicate a)

(<>) on predicates uses logical conjunction (&&) on the results. Without newtypes this equals liftA2 (&&).

(<>) :: Predicate a -> Predicate a -> Predicate a
Predicate pred <> Predicate pred' = Predicate a ->
  pred a && pred' a

Defined in Data.Functor.Contravariant

Methods

(<>) :: Predicate a -> Predicate a -> Predicate a

sconcat :: NonEmpty (Predicate a) -> Predicate a

stimes :: Integral b => b -> Predicate a -> Predicate a

Semigroup a => Semigroup (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

(<>) :: Identity a -> Identity a -> Identity a

sconcat :: NonEmpty (Identity a) -> Identity a

stimes :: Integral b => b -> Identity a -> Identity a

Semigroup (First a)

Since: base-4.9.0.0

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 (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 (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

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

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

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

(Generic a, Semigroup (Rep a ())) => Semigroup (Generically a)

Since: base-4.17.0.0

Defined in GHC.Generics

Methods

(<>) :: Generically a -> Generically a -> Generically a

sconcat :: NonEmpty (Generically a) -> Generically a

stimes :: Integral b => b -> Generically a -> Generically a

Semigroup p => Semigroup (Par1 p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

(<>) :: Par1 p -> Par1 p -> Par1 p

sconcat :: NonEmpty (Par1 p) -> Par1 p

stimes :: Integral b => b -> Par1 p -> Par1 p

Semigroup (IntMap a)

Since: containers-0.5.7

Defined in Data.IntMap.Internal

Methods

(<>) :: IntMap a -> IntMap a -> IntMap a

sconcat :: NonEmpty (IntMap a) -> IntMap a

stimes :: Integral b => b -> IntMap a -> IntMap a

Semigroup (Seq a)

Since: containers-0.5.7

Defined in Data.Sequence.Internal

Methods

(<>) :: Seq a -> Seq a -> Seq a

sconcat :: NonEmpty (Seq a) -> Seq a

stimes :: Integral b => b -> Seq a -> Seq a

Ord a => Semigroup (Intersection a)

Defined in Data.Set.Internal

Methods

(<>) :: Intersection a -> Intersection a -> Intersection a

sconcat :: NonEmpty (Intersection a) -> Intersection a

stimes :: Integral b => b -> Intersection a -> Intersection 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

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 (DList a)

Defined in Data.DList.Internal

Methods

(<>) :: DList a -> DList a -> DList a

sconcat :: NonEmpty (DList a) -> DList a

stimes :: Integral b => b -> DList a -> DList 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

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

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 (a)

Since: base-4.15

Defined in GHC.Base

Methods

(<>) :: (a) -> (a) -> (a)

sconcat :: NonEmpty (a) -> (a)

stimes :: Integral b => b -> (a) -> (a)

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 (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 (Op a b)

(<>) @(Op a b) without newtypes is (<>) @(b->a) = liftA2 (<>). This lifts the Semigroup operation (<>) over the output of a.

(<>) :: Op a b -> Op a b -> Op a b
Op f <> Op g = Op a -> f a <> g a

Defined in Data.Functor.Contravariant

Methods

(<>) :: Op a b -> Op a b -> Op a b

sconcat :: NonEmpty (Op a b) -> Op a b

stimes :: Integral b0 => b0 -> Op a b -> Op a b

Semigroup (Proxy s)

Since: base-4.9.0.0

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

Semigroup (U1 p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

(<>) :: U1 p -> U1 p -> U1 p

sconcat :: NonEmpty (U1 p) -> U1 p

stimes :: Integral b => b -> U1 p -> U1 p

Semigroup (V1 p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

(<>) :: V1 p -> V1 p -> V1 p

sconcat :: NonEmpty (V1 p) -> V1 p

stimes :: Integral b => b -> V1 p -> V1 p

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 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 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 a => Semigroup (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

(<>) :: Const a b -> Const a b -> Const a b

sconcat :: NonEmpty (Const a b) -> Const a b

stimes :: Integral b0 => b0 -> Const a b -> Const a b

(Applicative f, Semigroup a) => Semigroup (Ap f a)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

(<>) :: Ap f a -> Ap f a -> Ap f a

sconcat :: NonEmpty (Ap f a) -> Ap f a

stimes :: Integral b => b -> Ap f a -> Ap f a

Semigroup (f p) => Semigroup (Rec1 f p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

(<>) :: Rec1 f p -> Rec1 f p -> Rec1 f p

sconcat :: NonEmpty (Rec1 f p) -> Rec1 f p

stimes :: Integral b => b -> Rec1 f p -> Rec1 f p

(Semigroup a, Semigroup b, Semigroup c) => Semigroup (a, b, c)

Since: base-4.9.0.0

Defined in GHC.Base

Methods

(<>) :: (a, b, c) -> (a, b, c) -> (a, b, c)

sconcat :: NonEmpty (a, b, c) -> (a, b, c)

stimes :: Integral b0 => b0 -> (a, b, c) -> (a, b, c)

(Semigroup (f a), Semigroup (g a)) => Semigroup (Product f g a)

Since: base-4.16.0.0

Defined in Data.Functor.Product

Methods

(<>) :: Product f g a -> Product f g a -> Product f g a

sconcat :: NonEmpty (Product f g a) -> Product f g a

stimes :: Integral b => b -> Product f g a -> Product f g a

(Semigroup (f p), Semigroup (g p)) => Semigroup ((f :*: g) p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

(<>) :: (f :*: g) p -> (f :*: g) p -> (f :*: g) p

sconcat :: NonEmpty ((f :*: g) p) -> (f :*: g) p

stimes :: Integral b => b -> (f :*: g) p -> (f :*: g) p

Semigroup c => Semigroup (K1 i c p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

(<>) :: K1 i c p -> K1 i c p -> K1 i c p

sconcat :: NonEmpty (K1 i c p) -> K1 i c p

stimes :: Integral b => b -> K1 i c p -> K1 i c p

(Semigroup 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 (f (g a)) => Semigroup (Compose f g a)

Since: base-4.16.0.0

Defined in Data.Functor.Compose

Methods

(<>) :: Compose f g a -> Compose f g a -> Compose f g a

sconcat :: NonEmpty (Compose f g a) -> Compose f g a

stimes :: Integral b => b -> Compose f g a -> Compose f g a

Semigroup (f (g p)) => Semigroup ((f :.: g) p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

(<>) :: (f :.: g) p -> (f :.: g) p -> (f :.: g) p

sconcat :: NonEmpty ((f :.: g) p) -> (f :.: g) p

stimes :: Integral b => b -> (f :.: g) p -> (f :.: g) p

Semigroup (f p) => Semigroup (M1 i c f p)

Since: base-4.12.0.0

Defined in GHC.Generics

Methods

(<>) :: M1 i c f p -> M1 i c f p -> M1 i c f p

sconcat :: NonEmpty (M1 i c f p) -> M1 i c f p

stimes :: Integral b => b -> M1 i c f p -> M1 i c f p

(Semigroup 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)

class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where

Functors representing data structures that can be transformed to structures of the same shape by performing an Applicative (or, therefore, Monad) action on each element from left to right.

A more detailed description of what same shape means, the various methods, how traversals are constructed, and example advanced use-cases can be found in the Overview section of Data.Traversable.

For the class laws see the Laws section of Data.Traversable.

Minimal complete definition

traverse | sequenceA

Methods

traverse :: Applicative f => (a -> f b) -> t a -> f (t b)

Map each element of a structure to an action, evaluate these actions from left to right, and collect the results. For a version that ignores the results see traverse_.

Examples

Basic usage:

In the first two examples we show each evaluated action mapping to the output structure.

>>> traverse Just [1,2,3,4]
Just [1,2,3,4]

>>> traverse id [Right 1, Right 2, Right 3, Right 4]
Right [1,2,3,4]

In the next examples, we show that Nothing and Left values short circuit the created structure.

>>> traverse (const Nothing) [1,2,3,4]
Nothing

>>> traverse (\x -> if odd x then Just x else Nothing)  [1,2,3,4]
Nothing

>>> traverse id [Right 1, Right 2, Right 3, Right 4, Left 0]
Left 0

sequenceA :: Applicative f => t (f a) -> f (t a)

Evaluate each action in the structure from left to right, and collect the results. For a version that ignores the results see sequenceA_.

Examples

Basic usage:

For the first two examples we show sequenceA fully evaluating a a structure and collecting the results.

>>> sequenceA [Just 1, Just 2, Just 3]
Just [1,2,3]

>>> sequenceA [Right 1, Right 2, Right 3]
Right [1,2,3]

The next two example show Nothing and Just will short circuit the resulting structure if present in the input. For more context, check the Traversable instances for Either and Maybe.

>>> sequenceA [Just 1, Just 2, Just 3, Nothing]
Nothing

>>> sequenceA [Right 1, Right 2, Right 3, Left 4]
Left 4

mapM :: 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_.

Examples

mapM is literally a traverse with a type signature restricted to Monad. Its implementation may be more efficient due to additional power of Monad.

sequence :: 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_.

Examples

Basic usage:

The first two examples are instances where the input and and output of sequence are isomorphic.

>>> sequence $ Right [1,2,3,4]
[Right 1,Right 2,Right 3,Right 4]

>>> sequence $ [Right 1,Right 2,Right 3,Right 4]
Right [1,2,3,4]

The following examples demonstrate short circuit behavior for sequence.

>>> sequence $ Left [1,2,3,4]
Left [1,2,3,4]

>>> sequence $ [Left 0, Right 1,Right 2,Right 3,Right 4]
Left 0

Instances

Traversable ZipList

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> ZipList a -> f (ZipList b)

sequenceA :: Applicative f => ZipList (f a) -> f (ZipList a)

mapM :: Monad m => (a -> m b) -> ZipList a -> m (ZipList b)

sequence :: Monad m => ZipList (m a) -> m (ZipList a)

Traversable Complex

Since: base-4.9.0.0

Defined in Data.Complex

Methods

traverse :: Applicative f => (a -> f b) -> Complex a -> f (Complex b)

sequenceA :: Applicative f => Complex (f a) -> f (Complex a)

mapM :: Monad m => (a -> m b) -> Complex a -> m (Complex b)

sequence :: Monad m => Complex (m a) -> m (Complex a)

Traversable Identity

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Identity a -> f (Identity b)

sequenceA :: Applicative f => Identity (f a) -> f (Identity a)

mapM :: Monad m => (a -> m b) -> Identity a -> m (Identity b)

sequence :: Monad m => Identity (m a) -> m (Identity a)

Traversable First

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> First a -> f (First b)

sequenceA :: Applicative f => First (f a) -> f (First a)

mapM :: Monad m => (a -> m b) -> First a -> m (First b)

sequence :: Monad m => First (m a) -> m (First a)

Traversable Last

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Last a -> f (Last b)

sequenceA :: Applicative f => Last (f a) -> f (Last a)

mapM :: Monad m => (a -> m b) -> Last a -> m (Last b)

sequence :: Monad m => Last (m a) -> m (Last a)

Traversable Down

Since: base-4.12.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Down a -> f (Down b)

sequenceA :: Applicative f => Down (f a) -> f (Down a)

mapM :: Monad m => (a -> m b) -> Down a -> m (Down b)

sequence :: Monad m => Down (m a) -> m (Down a)

Traversable First

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

traverse :: Applicative f => (a -> f b) -> First a -> f (First b)

sequenceA :: Applicative f => First (f a) -> f (First a)

mapM :: Monad m => (a -> m b) -> First a -> m (First b)

sequence :: Monad m => First (m a) -> m (First a)

Traversable Last

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

traverse :: Applicative f => (a -> f b) -> Last a -> f (Last b)

sequenceA :: Applicative f => Last (f a) -> f (Last a)

mapM :: Monad m => (a -> m b) -> Last a -> m (Last b)

sequence :: Monad m => Last (m a) -> m (Last a)

Traversable Max

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

traverse :: Applicative f => (a -> f b) -> Max a -> f (Max b)

sequenceA :: Applicative f => Max (f a) -> f (Max a)

mapM :: Monad m => (a -> m b) -> Max a -> m (Max b)

sequence :: Monad m => Max (m a) -> m (Max a)

Traversable Min

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

traverse :: Applicative f => (a -> f b) -> Min a -> f (Min b)

sequenceA :: Applicative f => Min (f a) -> f (Min a)

mapM :: Monad m => (a -> m b) -> Min a -> m (Min b)

sequence :: Monad m => Min (m a) -> m (Min a)

Traversable Dual

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Dual a -> f (Dual b)

sequenceA :: Applicative f => Dual (f a) -> f (Dual a)

mapM :: Monad m => (a -> m b) -> Dual a -> m (Dual b)

sequence :: Monad m => Dual (m a) -> m (Dual a)

Traversable Product

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Product a -> f (Product b)

sequenceA :: Applicative f => Product (f a) -> f (Product a)

mapM :: Monad m => (a -> m b) -> Product a -> m (Product b)

sequence :: Monad m => Product (m a) -> m (Product a)

Traversable Sum

Since: base-4.8.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Sum a -> f (Sum b)

sequenceA :: Applicative f => Sum (f a) -> f (Sum a)

mapM :: Monad m => (a -> m b) -> Sum a -> m (Sum b)

sequence :: Monad m => Sum (m a) -> m (Sum a)

Traversable Par1

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Par1 a -> f (Par1 b)

sequenceA :: Applicative f => Par1 (f a) -> f (Par1 a)

mapM :: Monad m => (a -> m b) -> Par1 a -> m (Par1 b)

sequence :: Monad m => Par1 (m a) -> m (Par1 a)

Traversable IntMap

Traverses in order of increasing key.

Defined in Data.IntMap.Internal

Methods

traverse :: Applicative f => (a -> f b) -> IntMap a -> f (IntMap b)

sequenceA :: Applicative f => IntMap (f a) -> f (IntMap a)

mapM :: Monad m => (a -> m b) -> IntMap a -> m (IntMap b)

sequence :: Monad m => IntMap (m a) -> m (IntMap a)

Traversable Digit

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Digit a -> f (Digit b)

sequenceA :: Applicative f => Digit (f a) -> f (Digit a)

mapM :: Monad m => (a -> m b) -> Digit a -> m (Digit b)

sequence :: Monad m => Digit (m a) -> m (Digit a)

Traversable Elem

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Elem a -> f (Elem b)

sequenceA :: Applicative f => Elem (f a) -> f (Elem a)

mapM :: Monad m => (a -> m b) -> Elem a -> m (Elem b)

sequence :: Monad m => Elem (m a) -> m (Elem a)

Traversable FingerTree

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> FingerTree a -> f (FingerTree b)

sequenceA :: Applicative f => FingerTree (f a) -> f (FingerTree a)

mapM :: Monad m => (a -> m b) -> FingerTree a -> m (FingerTree b)

sequence :: Monad m => FingerTree (m a) -> m (FingerTree a)

Traversable Node

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Node a -> f (Node b)

sequenceA :: Applicative f => Node (f a) -> f (Node a)

mapM :: Monad m => (a -> m b) -> Node a -> m (Node b)

sequence :: Monad m => Node (m a) -> m (Node a)

Traversable Seq

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Seq a -> f (Seq b)

sequenceA :: Applicative f => Seq (f a) -> f (Seq a)

mapM :: Monad m => (a -> m b) -> Seq a -> m (Seq b)

sequence :: Monad m => Seq (m a) -> m (Seq a)

Traversable ViewL

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> ViewL a -> f (ViewL b)

sequenceA :: Applicative f => ViewL (f a) -> f (ViewL a)

mapM :: Monad m => (a -> m b) -> ViewL a -> m (ViewL b)

sequence :: Monad m => ViewL (m a) -> m (ViewL a)

Traversable ViewR

Defined in Data.Sequence.Internal

Methods

traverse :: Applicative f => (a -> f b) -> ViewR a -> f (ViewR b)

sequenceA :: Applicative f => ViewR (f a) -> f (ViewR a)

mapM :: Monad m => (a -> m b) -> ViewR a -> m (ViewR b)

sequence :: Monad m => ViewR (m a) -> m (ViewR a)

Traversable DList

Defined in Data.DList.Internal

Methods

traverse :: Applicative f => (a -> f b) -> DList a -> f (DList b)

sequenceA :: Applicative f => DList (f a) -> f (DList a)

mapM :: Monad m => (a -> m b) -> DList a -> m (DList b)

sequence :: Monad m => DList (m a) -> m (DList a)

Traversable NonEmpty

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> NonEmpty a -> f (NonEmpty b)

sequenceA :: Applicative f => NonEmpty (f a) -> f (NonEmpty a)

mapM :: Monad m => (a -> m b) -> NonEmpty a -> m (NonEmpty b)

sequence :: Monad m => NonEmpty (m a) -> m (NonEmpty a)

Traversable 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)

Traversable Solo

Since: base-4.15

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Solo a -> f (Solo b)

sequenceA :: Applicative f => Solo (f a) -> f (Solo a)

mapM :: Monad m => (a -> m b) -> Solo a -> m (Solo b)

sequence :: Monad m => Solo (m a) -> m (Solo a)

Traversable []

Since: base-2.1

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> [a] -> f [b]

sequenceA :: Applicative f => [f a] -> f [a]

mapM :: Monad m => (a -> m b) -> [a] -> m [b]

sequence :: Monad m => [m a] -> m [a]

Traversable (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)

Traversable (Proxy :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Proxy a -> f (Proxy b)

sequenceA :: Applicative f => Proxy (f a) -> f (Proxy a)

mapM :: Monad m => (a -> m b) -> Proxy a -> m (Proxy b)

sequence :: Monad m => Proxy (m a) -> m (Proxy a)

Traversable (Arg a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

traverse :: Applicative f => (a0 -> f b) -> Arg a a0 -> f (Arg a b)

sequenceA :: Applicative f => Arg a (f a0) -> f (Arg a a0)

mapM :: Monad m => (a0 -> m b) -> Arg a a0 -> m (Arg a b)

sequence :: Monad m => Arg a (m a0) -> m (Arg a a0)

Ix i => Traversable (Array i)

Since: base-2.1

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Array i a -> f (Array i b)

sequenceA :: Applicative f => Array i (f a) -> f (Array i a)

mapM :: Monad m => (a -> m b) -> Array i a -> m (Array i b)

sequence :: Monad m => Array i (m a) -> m (Array i a)

Traversable (U1 :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> U1 a -> f (U1 b)

sequenceA :: Applicative f => U1 (f a) -> f (U1 a)

mapM :: Monad m => (a -> m b) -> U1 a -> m (U1 b)

sequence :: Monad m => U1 (m a) -> m (U1 a)

Traversable (UAddr :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UAddr a -> f (UAddr b)

sequenceA :: Applicative f => UAddr (f a) -> f (UAddr a)

mapM :: Monad m => (a -> m b) -> UAddr a -> m (UAddr b)

sequence :: Monad m => UAddr (m a) -> m (UAddr a)

Traversable (UChar :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UChar a -> f (UChar b)

sequenceA :: Applicative f => UChar (f a) -> f (UChar a)

mapM :: Monad m => (a -> m b) -> UChar a -> m (UChar b)

sequence :: Monad m => UChar (m a) -> m (UChar a)

Traversable (UDouble :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UDouble a -> f (UDouble b)

sequenceA :: Applicative f => UDouble (f a) -> f (UDouble a)

mapM :: Monad m => (a -> m b) -> UDouble a -> m (UDouble b)

sequence :: Monad m => UDouble (m a) -> m (UDouble a)

Traversable (UFloat :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UFloat a -> f (UFloat b)

sequenceA :: Applicative f => UFloat (f a) -> f (UFloat a)

mapM :: Monad m => (a -> m b) -> UFloat a -> m (UFloat b)

sequence :: Monad m => UFloat (m a) -> m (UFloat a)

Traversable (UInt :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UInt a -> f (UInt b)

sequenceA :: Applicative f => UInt (f a) -> f (UInt a)

mapM :: Monad m => (a -> m b) -> UInt a -> m (UInt b)

sequence :: Monad m => UInt (m a) -> m (UInt a)

Traversable (UWord :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UWord a -> f (UWord b)

sequenceA :: Applicative f => UWord (f a) -> f (UWord a)

mapM :: Monad m => (a -> m b) -> UWord a -> m (UWord b)

sequence :: Monad m => UWord (m a) -> m (UWord a)

Traversable (V1 :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> V1 a -> f (V1 b)

sequenceA :: Applicative f => V1 (f a) -> f (V1 a)

mapM :: Monad m => (a -> m b) -> V1 a -> m (V1 b)

sequence :: Monad m => V1 (m a) -> m (V1 a)

Traversable (Map k)

Traverses in order of increasing key.

Defined in Data.Map.Internal

Methods

traverse :: Applicative f => (a -> f b) -> Map k a -> f (Map k b)

sequenceA :: Applicative f => Map k (f a) -> f (Map k a)

mapM :: Monad m => (a -> m b) -> Map k a -> m (Map k b)

sequence :: Monad m => Map k (m a) -> m (Map k a)

Traversable ((,) a)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a0 -> f b) -> (a, a0) -> f (a, b)

sequenceA :: Applicative f => (a, f a0) -> f (a, a0)

mapM :: Monad m => (a0 -> m b) -> (a, a0) -> m (a, b)

sequence :: Monad m => (a, m a0) -> m (a, a0)

Traversable (Const m :: Type -> Type)

Since: base-4.7.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Const m a -> f (Const m b)

sequenceA :: Applicative f => Const m (f a) -> f (Const m a)

mapM :: Monad m0 => (a -> m0 b) -> Const m a -> m0 (Const m b)

sequence :: Monad m0 => Const m (m0 a) -> m0 (Const m a)

Traversable f => Traversable (Ap f)

Since: base-4.12.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Ap f a -> f0 (Ap f b)

sequenceA :: Applicative f0 => Ap f (f0 a) -> f0 (Ap f a)

mapM :: Monad m => (a -> m b) -> Ap f a -> m (Ap f b)

sequence :: Monad m => Ap f (m a) -> m (Ap f a)

Traversable f => Traversable (Alt f)

Since: base-4.12.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Alt f a -> f0 (Alt f b)

sequenceA :: Applicative f0 => Alt f (f0 a) -> f0 (Alt f a)

mapM :: Monad m => (a -> m b) -> Alt f a -> m (Alt f b)

sequence :: Monad m => Alt f (m a) -> m (Alt f a)

Traversable f => Traversable (Rec1 f)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Rec1 f a -> f0 (Rec1 f b)

sequenceA :: Applicative f0 => Rec1 f (f0 a) -> f0 (Rec1 f a)

mapM :: Monad m => (a -> m b) -> Rec1 f a -> m (Rec1 f b)

sequence :: Monad m => Rec1 f (m a) -> m (Rec1 f a)

(Traversable f, Traversable g) => Traversable (Product f g)

Since: base-4.9.0.0

Defined in Data.Functor.Product

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Product f g a -> f0 (Product f g b)

sequenceA :: Applicative f0 => Product f g (f0 a) -> f0 (Product f g a)

mapM :: Monad m => (a -> m b) -> Product f g a -> m (Product f g b)

sequence :: Monad m => Product f g (m a) -> m (Product f g a)

(Traversable f, Traversable g) => Traversable (Sum f g)

Since: base-4.9.0.0

Defined in Data.Functor.Sum

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Sum f g a -> f0 (Sum f g b)

sequenceA :: Applicative f0 => Sum f g (f0 a) -> f0 (Sum f g a)

mapM :: Monad m => (a -> m b) -> Sum f g a -> m (Sum f g b)

sequence :: Monad m => Sum f g (m a) -> m (Sum f g a)

(Traversable f, Traversable g) => Traversable (f :*: g)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> (f :*: g) a -> f0 ((f :*: g) b)

sequenceA :: Applicative f0 => (f :*: g) (f0 a) -> f0 ((f :*: g) a)

mapM :: Monad m => (a -> m b) -> (f :*: g) a -> m ((f :*: g) b)

sequence :: Monad m => (f :*: g) (m a) -> m ((f :*: g) a)

(Traversable f, Traversable g) => Traversable (f :+: g)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> (f :+: g) a -> f0 ((f :+: g) b)

sequenceA :: Applicative f0 => (f :+: g) (f0 a) -> f0 ((f :+: g) a)

mapM :: Monad m => (a -> m b) -> (f :+: g) a -> m ((f :+: g) b)

sequence :: Monad m => (f :+: g) (m a) -> m ((f :+: g) a)

Traversable (K1 i c :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> K1 i c a -> f (K1 i c b)

sequenceA :: Applicative f => K1 i c (f a) -> f (K1 i c a)

mapM :: Monad m => (a -> m b) -> K1 i c a -> m (K1 i c b)

sequence :: Monad m => K1 i c (m a) -> m (K1 i c a)

(Traversable f, Traversable g) => Traversable (Compose f g)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Compose f g a -> f0 (Compose f g b)

sequenceA :: Applicative f0 => Compose f g (f0 a) -> f0 (Compose f g a)

mapM :: Monad m => (a -> m b) -> Compose f g a -> m (Compose f g b)

sequence :: Monad m => Compose f g (m a) -> m (Compose f g a)

(Traversable f, Traversable g) => Traversable (f :.: g)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> (f :.: g) a -> f0 ((f :.: g) b)

sequenceA :: Applicative f0 => (f :.: g) (f0 a) -> f0 ((f :.: g) a)

mapM :: Monad m => (a -> m b) -> (f :.: g) a -> m ((f :.: g) b)

sequence :: Monad m => (f :.: g) (m a) -> m ((f :.: g) a)

Traversable f => Traversable (M1 i c f)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f0 => (a -> f0 b) -> M1 i c f a -> f0 (M1 i c f b)

sequenceA :: Applicative f0 => M1 i c f (f0 a) -> f0 (M1 i c f a)

mapM :: Monad m => (a -> m b) -> M1 i c f a -> m (M1 i c f b)

sequence :: Monad m => M1 i c f (m a) -> m (M1 i c f a)

for :: (Traversable t, Applicative f) => t a -> (a -> f b) -> f (t b)

for is traverse with its arguments flipped. For a version that ignores the results see for_.

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_.

mapAccumL :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b)

The mapAccumL function behaves like a combination of fmap and foldl; it applies a function to each element of a structure, passing an accumulating parameter from left to right, and returning a final value of this accumulator together with the new structure.

Examples

Basic usage:

>>> mapAccumL (\a b -> (a + b, a)) 0 [1..10]
(55,[0,1,3,6,10,15,21,28,36,45])

>>> mapAccumL (\a b -> (a <> show b, a)) "0" [1..5]
("012345",["0","01","012","0123","01234"])

mapAccumR :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b)

The mapAccumR function behaves like a combination of fmap and foldr; it applies a function to each element of a structure, passing an accumulating parameter from right to left, and returning a final value of this accumulator together with the new structure.

Examples

Basic usage:

>>> mapAccumR (\a b -> (a + b, a)) 0 [1..10]
(55,[54,52,49,45,40,34,27,19,10,0])

>>> mapAccumR (\a b -> (a <> show b, a)) "0" [1..5]
("054321",["05432","0543","054","05","0"])

fst :: (a, b) -> a

Extract the first component 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]

snd :: (a, b) -> b

Extract the second component of a pair.

curry :: ((a, b) -> c) -> a -> b -> c

curry converts an uncurried function to a curried function.

Examples

>>> curry fst 1 2
1

swap :: (a, b) -> (b, a)

Swap the components of a pair.

class Typeable (a :: k)

The class Typeable allows a concrete representation of a type to be calculated.

Minimal complete definition

typeRep#

data Void

Uninhabited data type

Since: base-4.8.0.0

Instances

Data Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Void -> c Void

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Void

toConstr :: Void -> Constr

dataTypeOf :: Void -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Void)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Void)

gmapT :: (forall b. Data b => b -> b) -> Void -> Void

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r

gmapQ :: (forall d. Data d => d -> u) -> Void -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Void -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Void -> m Void

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void

Semigroup Void

Since: base-4.9.0.0

Defined in Data.Void

Methods

(<>) :: Void -> Void -> Void

sconcat :: NonEmpty Void -> Void

stimes :: Integral b => b -> Void -> Void

Exception Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

toException :: Void -> SomeException

fromException :: SomeException -> Maybe Void

displayException :: Void -> String

Generic Void

Defined in Data.Void

Associated Types

type Rep Void :: Type -> Type

Methods

from :: Void -> Rep Void x

to :: Rep Void x -> Void

Ix Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

range :: (Void, Void) -> [Void]

index :: (Void, Void) -> Void -> Int

unsafeIndex :: (Void, Void) -> Void -> Int

inRange :: (Void, Void) -> Void -> Bool

rangeSize :: (Void, Void) -> Int

unsafeRangeSize :: (Void, Void) -> Int

Read Void

Reading a Void value is always a parse error, considering Void as a data type with no constructors.

Since: base-4.8.0.0

Defined in Data.Void

Methods

readsPrec :: Int -> ReadS Void

readList :: ReadS [Void]

readPrec :: ReadPrec Void

readListPrec :: ReadPrec [Void]

Show Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

showsPrec :: Int -> Void -> ShowS

show :: Void -> String

showList :: [Void] -> ShowS

Eq Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

(==) :: Void -> Void -> Bool

(/=) :: Void -> Void -> Bool

Ord Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

compare :: Void -> Void -> Ordering

(<) :: Void -> Void -> Bool

(<=) :: Void -> Void -> Bool

(>) :: Void -> Void -> Bool

(>=) :: Void -> Void -> Bool

max :: Void -> Void -> Void

min :: Void -> Void -> Void

type Rep Void

Since: base-4.8.0.0

Defined in Data.Void

type Rep Void = D1 ('MetaData "Void" "Data.Void" "base" 'False) (V1 :: Type -> Type)

data Word8

8-bit unsigned integer type

Instances

Bits Word8

Since: base-2.1

Defined in GHC.Word

Methods

(.&.) :: Word8 -> Word8 -> Word8

(.|.) :: Word8 -> Word8 -> Word8

xor :: Word8 -> Word8 -> Word8

complement :: Word8 -> Word8

shift :: Word8 -> Int -> Word8

rotate :: Word8 -> Int -> Word8

zeroBits :: Word8

bit :: Int -> Word8

setBit :: Word8 -> Int -> Word8

clearBit :: Word8 -> Int -> Word8

complementBit :: Word8 -> Int -> Word8

testBit :: Word8 -> Int -> Bool

bitSizeMaybe :: Word8 -> Maybe Int

bitSize :: Word8 -> Int

isSigned :: Word8 -> Bool

shiftL :: Word8 -> Int -> Word8

unsafeShiftL :: Word8 -> Int -> Word8

shiftR :: Word8 -> Int -> Word8

unsafeShiftR :: Word8 -> Int -> Word8

rotateL :: Word8 -> Int -> Word8

rotateR :: Word8 -> Int -> Word8

popCount :: Word8 -> Int

FiniteBits Word8

Since: base-4.6.0.0

Defined in GHC.Word

Methods

finiteBitSize :: Word8 -> Int

countLeadingZeros :: Word8 -> Int

countTrailingZeros :: Word8 -> Int

Bounded Word8

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word8

maxBound :: Word8

Enum Word8

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word8 -> Word8

pred :: Word8 -> Word8

toEnum :: Int -> Word8

fromEnum :: Word8 -> Int

enumFrom :: Word8 -> [Word8]

enumFromThen :: Word8 -> Word8 -> [Word8]

enumFromTo :: Word8 -> Word8 -> [Word8]

enumFromThenTo :: Word8 -> Word8 -> Word8 -> [Word8]

Ix Word8

Since: base-2.1

Defined in GHC.Word

Methods

range :: (Word8, Word8) -> [Word8]

index :: (Word8, Word8) -> Word8 -> Int

unsafeIndex :: (Word8, Word8) -> Word8 -> Int

inRange :: (Word8, Word8) -> Word8 -> Bool

rangeSize :: (Word8, Word8) -> Int

unsafeRangeSize :: (Word8, Word8) -> Int

Num Word8

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word8 -> Word8 -> Word8

(-) :: Word8 -> Word8 -> Word8

(*) :: Word8 -> Word8 -> Word8

negate :: Word8 -> Word8

abs :: Word8 -> Word8

signum :: Word8 -> Word8

fromInteger :: Integer -> Word8

Read Word8

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word8

readList :: ReadS [Word8]

readPrec :: ReadPrec Word8

readListPrec :: ReadPrec [Word8]

Integral Word8

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word8 -> Word8 -> Word8

rem :: Word8 -> Word8 -> Word8

div :: Word8 -> Word8 -> Word8

mod :: Word8 -> Word8 -> Word8

quotRem :: Word8 -> Word8 -> (Word8, Word8)

divMod :: Word8 -> Word8 -> (Word8, Word8)

toInteger :: Word8 -> Integer

Real Word8

Since: base-2.1

Defined in GHC.Word

Methods

toRational :: Word8 -> Rational

Show Word8

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word8 -> ShowS

show :: Word8 -> String

showList :: [Word8] -> ShowS

Default Word8

Defined in Data.Default.Class

Methods

def :: Word8

Eq Word8

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word8 -> Word8 -> Bool

(/=) :: Word8 -> Word8 -> Bool

Ord Word8

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word8 -> Word8 -> Ordering

(<) :: Word8 -> Word8 -> Bool

(<=) :: Word8 -> Word8 -> Bool

(>) :: Word8 -> Word8 -> Bool

(>=) :: Word8 -> Word8 -> Bool

max :: Word8 -> Word8 -> Word8

min :: Word8 -> Word8 -> Word8

data Word

A Word is an unsigned integral type, with the same size as Int.

Instances

Bits Word

Since: base-2.1

Defined in GHC.Bits

Methods

(.&.) :: Word -> Word -> Word

(.|.) :: Word -> Word -> Word

xor :: Word -> Word -> Word

complement :: Word -> Word

shift :: Word -> Int -> Word

rotate :: Word -> Int -> Word

zeroBits :: Word

bit :: Int -> Word

setBit :: Word -> Int -> Word

clearBit :: Word -> Int -> Word

complementBit :: Word -> Int -> Word

testBit :: Word -> Int -> Bool

bitSizeMaybe :: Word -> Maybe Int

bitSize :: Word -> Int

isSigned :: Word -> Bool

shiftL :: Word -> Int -> Word

unsafeShiftL :: Word -> Int -> Word

shiftR :: Word -> Int -> Word

unsafeShiftR :: Word -> Int -> Word

rotateL :: Word -> Int -> Word

rotateR :: Word -> Int -> Word

popCount :: Word -> Int

FiniteBits Word

Since: base-4.6.0.0

Defined in GHC.Bits

Methods

finiteBitSize :: Word -> Int

countLeadingZeros :: Word -> Int

countTrailingZeros :: Word -> Int

Bounded Word

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Word

maxBound :: Word

Enum Word

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Word -> Word

pred :: Word -> Word

toEnum :: Int -> Word

fromEnum :: Word -> Int

enumFrom :: Word -> [Word]

enumFromThen :: Word -> Word -> [Word]

enumFromTo :: Word -> Word -> [Word]

enumFromThenTo :: Word -> Word -> Word -> [Word]

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

Read Word

Since: base-4.5.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word

readList :: ReadS [Word]

readPrec :: ReadPrec Word

readListPrec :: ReadPrec [Word]

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

Real Word

Since: base-2.1

Defined in GHC.Real

Methods

toRational :: Word -> Rational

Show Word

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Word -> ShowS

show :: Word -> String

showList :: [Word] -> ShowS

Default Word

Defined in Data.Default.Class

Methods

def :: Word

Eq Word

Defined in GHC.Classes

Methods

(==) :: Word -> Word -> Bool

(/=) :: Word -> Word -> Bool

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

Generic1 (URec Word :: k -> Type)

Defined in GHC.Generics

Associated Types

type Rep1 (URec Word) :: k -> Type

Methods

from1 :: forall (a :: k0). URec Word a -> Rep1 (URec Word) a

to1 :: forall (a :: k0). Rep1 (URec Word) a -> URec Word a

Foldable (UWord :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => UWord m -> m

foldMap :: Monoid m => (a -> m) -> UWord a -> m

foldMap' :: Monoid m => (a -> m) -> UWord a -> m

foldr :: (a -> b -> b) -> b -> UWord a -> b

foldr' :: (a -> b -> b) -> b -> UWord a -> b

foldl :: (b -> a -> b) -> b -> UWord a -> b

foldl' :: (b -> a -> b) -> b -> UWord a -> b

foldr1 :: (a -> a -> a) -> UWord a -> a

foldl1 :: (a -> a -> a) -> UWord a -> a

toList :: UWord a -> [a]

null :: UWord a -> Bool

length :: UWord a -> Int

elem :: Eq a => a -> UWord a -> Bool

maximum :: Ord a => UWord a -> a

minimum :: Ord a => UWord a -> a

sum :: Num a => UWord a -> a

product :: Num a => UWord a -> a

Traversable (UWord :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UWord a -> f (UWord b)

sequenceA :: Applicative f => UWord (f a) -> f (UWord a)

mapM :: Monad m => (a -> m b) -> UWord a -> m (UWord b)

sequence :: Monad m => UWord (m a) -> m (UWord a)

Functor (URec Word :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Word a -> URec Word b

(<$) :: a -> URec Word b -> URec Word a

Generic (URec Word p)

Defined in GHC.Generics

Associated Types

type Rep (URec Word p) :: Type -> Type

Methods

from :: URec Word p -> Rep (URec Word p) x

to :: Rep (URec Word p) x -> URec Word p

Show (URec Word p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> URec Word p -> ShowS

show :: URec Word p -> String

showList :: [URec Word p] -> ShowS

Eq (URec Word p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

(==) :: URec Word p -> URec Word p -> Bool

(/=) :: URec Word p -> URec Word p -> Bool

Ord (URec Word p)

Since: base-4.9.0.0

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

data URec Word (p :: k)

Used for marking occurrences of Word#

Since: base-4.9.0.0

Defined in GHC.Generics

data URec Word (p :: k) = UWord {

• uWord# :: Word#

}

type Rep1 (URec Word :: k -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

type Rep1 (URec Word :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UWord" 'PrefixI 'True) (S1 ('MetaSel ('Just "uWord#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UWord :: k -> Type)))

type Rep (URec Word p)

Since: base-4.9.0.0

Defined in GHC.Generics

type Rep (URec Word p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UWord" 'PrefixI 'True) (S1 ('MetaSel ('Just "uWord#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UWord :: Type -> Type)))

data Word64

64-bit unsigned integer type

Instances

Bits Word64

Since: base-2.1

Defined in GHC.Word

Methods

(.&.) :: Word64 -> Word64 -> Word64

(.|.) :: Word64 -> Word64 -> Word64

xor :: Word64 -> Word64 -> Word64

complement :: Word64 -> Word64

shift :: Word64 -> Int -> Word64

rotate :: Word64 -> Int -> Word64

zeroBits :: Word64

bit :: Int -> Word64

setBit :: Word64 -> Int -> Word64

clearBit :: Word64 -> Int -> Word64

complementBit :: Word64 -> Int -> Word64

testBit :: Word64 -> Int -> Bool

bitSizeMaybe :: Word64 -> Maybe Int

bitSize :: Word64 -> Int

isSigned :: Word64 -> Bool

shiftL :: Word64 -> Int -> Word64

unsafeShiftL :: Word64 -> Int -> Word64

shiftR :: Word64 -> Int -> Word64

unsafeShiftR :: Word64 -> Int -> Word64

rotateL :: Word64 -> Int -> Word64

rotateR :: Word64 -> Int -> Word64

popCount :: Word64 -> Int

FiniteBits Word64

Since: base-4.6.0.0

Defined in GHC.Word

Methods

finiteBitSize :: Word64 -> Int

countLeadingZeros :: Word64 -> Int

countTrailingZeros :: Word64 -> Int

Bounded Word64

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word64

maxBound :: Word64

Enum Word64

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word64 -> Word64

pred :: Word64 -> Word64

toEnum :: Int -> Word64

fromEnum :: Word64 -> Int

enumFrom :: Word64 -> [Word64]

enumFromThen :: Word64 -> Word64 -> [Word64]

enumFromTo :: Word64 -> Word64 -> [Word64]

enumFromThenTo :: Word64 -> Word64 -> Word64 -> [Word64]

Ix Word64

Since: base-2.1

Defined in GHC.Word

Methods

range :: (Word64, Word64) -> [Word64]

index :: (Word64, Word64) -> Word64 -> Int

unsafeIndex :: (Word64, Word64) -> Word64 -> Int

inRange :: (Word64, Word64) -> Word64 -> Bool

rangeSize :: (Word64, Word64) -> Int

unsafeRangeSize :: (Word64, Word64) -> Int

Num Word64

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word64 -> Word64 -> Word64

(-) :: Word64 -> Word64 -> Word64

(*) :: Word64 -> Word64 -> Word64

negate :: Word64 -> Word64

abs :: Word64 -> Word64

signum :: Word64 -> Word64

fromInteger :: Integer -> Word64

Read Word64

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word64

readList :: ReadS [Word64]

readPrec :: ReadPrec Word64

readListPrec :: ReadPrec [Word64]

Integral Word64

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word64 -> Word64 -> Word64

rem :: Word64 -> Word64 -> Word64

div :: Word64 -> Word64 -> Word64

mod :: Word64 -> Word64 -> Word64

quotRem :: Word64 -> Word64 -> (Word64, Word64)

divMod :: Word64 -> Word64 -> (Word64, Word64)

toInteger :: Word64 -> Integer

Real Word64

Since: base-2.1

Defined in GHC.Word

Methods

toRational :: Word64 -> Rational

Show Word64

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word64 -> ShowS

show :: Word64 -> String

showList :: [Word64] -> ShowS

Default Word64

Defined in Data.Default.Class

Methods

def :: Word64

Eq Word64

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word64 -> Word64 -> Bool

(/=) :: Word64 -> Word64 -> Bool

Ord Word64

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word64 -> Word64 -> Ordering

(<) :: Word64 -> Word64 -> Bool

(<=) :: Word64 -> Word64 -> Bool

(>) :: Word64 -> Word64 -> Bool

(>=) :: Word64 -> Word64 -> Bool

max :: Word64 -> Word64 -> Word64

min :: Word64 -> Word64 -> Word64

data Word32

32-bit unsigned integer type

Instances

Bits Word32

Since: base-2.1

Defined in GHC.Word

Methods

(.&.) :: Word32 -> Word32 -> Word32

(.|.) :: Word32 -> Word32 -> Word32

xor :: Word32 -> Word32 -> Word32

complement :: Word32 -> Word32

shift :: Word32 -> Int -> Word32

rotate :: Word32 -> Int -> Word32

zeroBits :: Word32

bit :: Int -> Word32

setBit :: Word32 -> Int -> Word32

clearBit :: Word32 -> Int -> Word32

complementBit :: Word32 -> Int -> Word32

testBit :: Word32 -> Int -> Bool

bitSizeMaybe :: Word32 -> Maybe Int

bitSize :: Word32 -> Int

isSigned :: Word32 -> Bool

shiftL :: Word32 -> Int -> Word32

unsafeShiftL :: Word32 -> Int -> Word32

shiftR :: Word32 -> Int -> Word32

unsafeShiftR :: Word32 -> Int -> Word32

rotateL :: Word32 -> Int -> Word32

rotateR :: Word32 -> Int -> Word32

popCount :: Word32 -> Int

FiniteBits Word32

Since: base-4.6.0.0

Defined in GHC.Word

Methods

finiteBitSize :: Word32 -> Int

countLeadingZeros :: Word32 -> Int

countTrailingZeros :: Word32 -> Int

Bounded Word32

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word32

maxBound :: Word32

Enum Word32

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word32 -> Word32

pred :: Word32 -> Word32

toEnum :: Int -> Word32

fromEnum :: Word32 -> Int

enumFrom :: Word32 -> [Word32]

enumFromThen :: Word32 -> Word32 -> [Word32]

enumFromTo :: Word32 -> Word32 -> [Word32]

enumFromThenTo :: Word32 -> Word32 -> Word32 -> [Word32]

Ix Word32

Since: base-2.1

Defined in GHC.Word

Methods

range :: (Word32, Word32) -> [Word32]

index :: (Word32, Word32) -> Word32 -> Int

unsafeIndex :: (Word32, Word32) -> Word32 -> Int

inRange :: (Word32, Word32) -> Word32 -> Bool

rangeSize :: (Word32, Word32) -> Int

unsafeRangeSize :: (Word32, Word32) -> Int

Num Word32

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word32 -> Word32 -> Word32

(-) :: Word32 -> Word32 -> Word32

(*) :: Word32 -> Word32 -> Word32

negate :: Word32 -> Word32

abs :: Word32 -> Word32

signum :: Word32 -> Word32

fromInteger :: Integer -> Word32

Read Word32

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word32

readList :: ReadS [Word32]

readPrec :: ReadPrec Word32

readListPrec :: ReadPrec [Word32]

Integral Word32

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word32 -> Word32 -> Word32

rem :: Word32 -> Word32 -> Word32

div :: Word32 -> Word32 -> Word32

mod :: Word32 -> Word32 -> Word32

quotRem :: Word32 -> Word32 -> (Word32, Word32)

divMod :: Word32 -> Word32 -> (Word32, Word32)

toInteger :: Word32 -> Integer

Real Word32

Since: base-2.1

Defined in GHC.Word

Methods

toRational :: Word32 -> Rational

Show Word32

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word32 -> ShowS

show :: Word32 -> String

showList :: [Word32] -> ShowS

Default Word32

Defined in Data.Default.Class

Methods

def :: Word32

Eq Word32

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word32 -> Word32 -> Bool

(/=) :: Word32 -> Word32 -> Bool

Ord Word32

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word32 -> Word32 -> Ordering

(<) :: Word32 -> Word32 -> Bool

(<=) :: Word32 -> Word32 -> Bool

(>) :: Word32 -> Word32 -> Bool

(>=) :: Word32 -> Word32 -> Bool

max :: Word32 -> Word32 -> Word32

min :: Word32 -> Word32 -> Word32

data Word16

16-bit unsigned integer type

Instances

Bits Word16

Since: base-2.1

Defined in GHC.Word

Methods

(.&.) :: Word16 -> Word16 -> Word16

(.|.) :: Word16 -> Word16 -> Word16

xor :: Word16 -> Word16 -> Word16

complement :: Word16 -> Word16

shift :: Word16 -> Int -> Word16

rotate :: Word16 -> Int -> Word16

zeroBits :: Word16

bit :: Int -> Word16

setBit :: Word16 -> Int -> Word16

clearBit :: Word16 -> Int -> Word16

complementBit :: Word16 -> Int -> Word16

testBit :: Word16 -> Int -> Bool

bitSizeMaybe :: Word16 -> Maybe Int

bitSize :: Word16 -> Int

isSigned :: Word16 -> Bool

shiftL :: Word16 -> Int -> Word16

unsafeShiftL :: Word16 -> Int -> Word16

shiftR :: Word16 -> Int -> Word16

unsafeShiftR :: Word16 -> Int -> Word16

rotateL :: Word16 -> Int -> Word16

rotateR :: Word16 -> Int -> Word16

popCount :: Word16 -> Int

FiniteBits Word16

Since: base-4.6.0.0

Defined in GHC.Word

Methods

finiteBitSize :: Word16 -> Int

countLeadingZeros :: Word16 -> Int

countTrailingZeros :: Word16 -> Int

Bounded Word16

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word16

maxBound :: Word16

Enum Word16

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word16 -> Word16

pred :: Word16 -> Word16

toEnum :: Int -> Word16

fromEnum :: Word16 -> Int

enumFrom :: Word16 -> [Word16]

enumFromThen :: Word16 -> Word16 -> [Word16]

enumFromTo :: Word16 -> Word16 -> [Word16]

enumFromThenTo :: Word16 -> Word16 -> Word16 -> [Word16]

Ix Word16

Since: base-2.1

Defined in GHC.Word

Methods

range :: (Word16, Word16) -> [Word16]

index :: (Word16, Word16) -> Word16 -> Int

unsafeIndex :: (Word16, Word16) -> Word16 -> Int

inRange :: (Word16, Word16) -> Word16 -> Bool

rangeSize :: (Word16, Word16) -> Int

unsafeRangeSize :: (Word16, Word16) -> Int

Num Word16

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word16 -> Word16 -> Word16

(-) :: Word16 -> Word16 -> Word16

(*) :: Word16 -> Word16 -> Word16

negate :: Word16 -> Word16

abs :: Word16 -> Word16

signum :: Word16 -> Word16

fromInteger :: Integer -> Word16

Read Word16

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Word16

readList :: ReadS [Word16]

readPrec :: ReadPrec Word16

readListPrec :: ReadPrec [Word16]

Integral Word16

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word16 -> Word16 -> Word16

rem :: Word16 -> Word16 -> Word16

div :: Word16 -> Word16 -> Word16

mod :: Word16 -> Word16 -> Word16

quotRem :: Word16 -> Word16 -> (Word16, Word16)

divMod :: Word16 -> Word16 -> (Word16, Word16)

toInteger :: Word16 -> Integer

Real Word16

Since: base-2.1

Defined in GHC.Word

Methods

toRational :: Word16 -> Rational

Show Word16

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word16 -> ShowS

show :: Word16 -> String

showList :: [Word16] -> ShowS

Default Word16

Defined in Data.Default.Class

Methods

def :: Word16

Eq Word16

Since: base-2.1

Defined in GHC.Word

Methods

(==) :: Word16 -> Word16 -> Bool

(/=) :: Word16 -> Word16 -> Bool

Ord Word16

Since: base-2.1

Defined in GHC.Word

Methods

compare :: Word16 -> Word16 -> Ordering

(<) :: Word16 -> Word16 -> Bool

(<=) :: Word16 -> Word16 -> Bool

(>) :: Word16 -> Word16 -> Bool

(>=) :: Word16 -> Word16 -> Bool

max :: Word16 -> Word16 -> Word16

min :: Word16 -> Word16 -> Word16

ord :: Char -> Int

The fromEnum method restricted to the type Char.

seq :: forall {r :: RuntimeRep} a (b :: TYPE r). a -> b -> b infixr 0

The value of seq a b is bottom if a is bottom, and otherwise equal to b. In other words, it evaluates the first argument a to weak head normal form (WHNF). seq is usually introduced to improve performance by avoiding unneeded laziness.

A note on evaluation order: the expression seq a b does not guarantee that a will be evaluated before b. The only guarantee given by seq is that the both a and b will be evaluated before seq returns a value. In particular, this means that b may be evaluated before a. If you need to guarantee a specific order of evaluation, you must use the function pseq from the "parallel" package.

minInt :: Int

maxInt :: Int

($!) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b infixr 0

Strict (call-by-value) application operator. It takes a function and an argument, evaluates the argument to weak head normal form (WHNF), then calls the function with that value.

class Bounded a where

The Bounded class is used to name the upper and lower limits of a type. Ord is not a superclass of Bounded since types that are not totally ordered may also have upper and lower bounds.

The Bounded class may be derived for any enumeration type; minBound is the first constructor listed in the data declaration and maxBound is the last. Bounded may also be derived for single-constructor datatypes whose constituent types are in Bounded.

Methods

minBound :: a

maxBound :: a

Instances

Bounded Associativity

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

minBound :: Associativity

maxBound :: Associativity

Bounded DecidedStrictness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

minBound :: DecidedStrictness

maxBound :: DecidedStrictness

Bounded SourceStrictness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

minBound :: SourceStrictness

maxBound :: SourceStrictness

Bounded SourceUnpackedness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

minBound :: SourceUnpackedness

maxBound :: SourceUnpackedness

Bounded Int16

Since: base-2.1

Defined in GHC.Int

Methods

minBound :: Int16

maxBound :: Int16

Bounded Int32

Since: base-2.1

Defined in GHC.Int

Methods

minBound :: Int32

maxBound :: Int32

Bounded Int64

Since: base-2.1

Defined in GHC.Int

Methods

minBound :: Int64

maxBound :: Int64

Bounded Int8

Since: base-2.1

Defined in GHC.Int

Methods

minBound :: Int8

maxBound :: Int8

Bounded Word16

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word16

maxBound :: Word16

Bounded Word32

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word32

maxBound :: Word32

Bounded Word64

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word64

maxBound :: Word64

Bounded Word8

Since: base-2.1

Defined in GHC.Word

Methods

minBound :: Word8

maxBound :: Word8

Bounded Ordering

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Ordering

maxBound :: Ordering

Bounded ()

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: ()

maxBound :: ()

Bounded Bool

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Bool

maxBound :: Bool

Bounded Char

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Char

maxBound :: Char

Bounded Int

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Int

maxBound :: Int

Bounded Levity

Since: base-4.16.0.0

Defined in GHC.Enum

Methods

minBound :: Levity

maxBound :: Levity

Bounded VecCount

Since: base-4.10.0.0

Defined in GHC.Enum

Methods

minBound :: VecCount

maxBound :: VecCount

Bounded VecElem

Since: base-4.10.0.0

Defined in GHC.Enum

Methods

minBound :: VecElem

maxBound :: VecElem

Bounded Word

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: Word

maxBound :: Word

Bounded a => Bounded (And a)

Since: base-4.16

Defined in Data.Bits

Methods

minBound :: And a

maxBound :: And a

Bounded a => Bounded (Iff a)

Since: base-4.16

Defined in Data.Bits

Methods

minBound :: Iff a

maxBound :: Iff a

Bounded a => Bounded (Ior a)

Since: base-4.16

Defined in Data.Bits

Methods

minBound :: Ior a

maxBound :: Ior a

Bounded a => Bounded (Xor a)

Since: base-4.16

Defined in Data.Bits

Methods

minBound :: Xor a

maxBound :: Xor a

Bounded a => Bounded (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

minBound :: Identity a

maxBound :: Identity a

Bounded a => Bounded (Down a)

Swaps minBound and maxBound of the underlying type.

Since: base-4.14.0.0

Defined in Data.Ord

Methods

minBound :: Down a

maxBound :: Down a

Bounded a => Bounded (First a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

minBound :: First a

maxBound :: First a

Bounded a => Bounded (Last a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

minBound :: Last a

maxBound :: Last a

Bounded a => Bounded (Max a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

minBound :: Max a

maxBound :: Max a

Bounded a => Bounded (Min a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

minBound :: Min a

maxBound :: Min a

Bounded m => Bounded (WrappedMonoid m)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

minBound :: WrappedMonoid m

maxBound :: WrappedMonoid m

Bounded a => Bounded (a)

Defined in GHC.Enum

Methods

minBound :: (a)

maxBound :: (a)

Bounded (Proxy t)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

minBound :: Proxy t

maxBound :: Proxy t

(Bounded a, Bounded b) => Bounded (a, b)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b)

maxBound :: (a, b)

Bounded a => Bounded (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

minBound :: Const a b

maxBound :: Const a b

(Applicative f, Bounded a) => Bounded (Ap f a)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

minBound :: Ap f a

maxBound :: Ap f a

a ~ b => Bounded (a :~: b)

Since: base-4.7.0.0

Defined in Data.Type.Equality

Methods

minBound :: a :~: b

maxBound :: a :~: b

(Bounded a, Bounded b, Bounded c) => Bounded (a, b, c)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c)

maxBound :: (a, b, c)

a ~~ b => Bounded (a :~~: b)

Since: base-4.10.0.0

Defined in Data.Type.Equality

Methods

minBound :: a :~~: b

maxBound :: a :~~: b

(Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a, b, c, d)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d)

maxBound :: (a, b, c, d)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a, b, c, d, e)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e)

maxBound :: (a, b, c, d, e)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f) => Bounded (a, b, c, d, e, f)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f)

maxBound :: (a, b, c, d, e, f)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g) => Bounded (a, b, c, d, e, f, g)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g)

maxBound :: (a, b, c, d, e, f, g)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h) => Bounded (a, b, c, d, e, f, g, h)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h)

maxBound :: (a, b, c, d, e, f, g, h)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i) => Bounded (a, b, c, d, e, f, g, h, i)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i)

maxBound :: (a, b, c, d, e, f, g, h, i)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j) => Bounded (a, b, c, d, e, f, g, h, i, j)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j)

maxBound :: (a, b, c, d, e, f, g, h, i, j)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k) => Bounded (a, b, c, d, e, f, g, h, i, j, k)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k, l)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

(Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n, Bounded o) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

Since: base-2.1

Defined in GHC.Enum

Methods

minBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

maxBound :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

class Enum a where

Class Enum defines operations on sequentially ordered types.

The enumFrom... methods are used in Haskell's translation of arithmetic sequences.

Instances of Enum may be derived for any enumeration type (types whose constructors have no fields). The nullary constructors are assumed to be numbered left-to-right by fromEnum from 0 through n-1. See Chapter 10 of the Haskell Report for more details.

For any type that is an instance of class Bounded as well as Enum, the following should hold:

• The calls succ maxBound and pred minBound should result in a runtime error.
• fromEnum and toEnum should give a runtime error if the result value is not representable in the result type. For example, toEnum 7 :: Bool is an error.
• enumFrom and enumFromThen should be defined with an implicit bound, thus:

   enumFrom     x   = enumFromTo     x maxBound
   enumFromThen x y = enumFromThenTo x y bound
     where
       bound | fromEnum y >= fromEnum x = maxBound
             | otherwise                = minBound

Minimal complete definition

toEnum, fromEnum

Methods

succ :: a -> a

the successor of a value. For numeric types, succ adds 1.

pred :: a -> a

the predecessor of a value. For numeric types, pred subtracts 1.

toEnum :: Int -> a

Convert from an Int.

fromEnum :: a -> Int

Convert to an Int. It is implementation-dependent what fromEnum returns when applied to a value that is too large to fit in an Int.

enumFrom :: a -> [a]

Used in Haskell's translation of [n..] with [n..] = enumFrom n, a possible implementation being enumFrom n = n : enumFrom (succ n). For example:

• enumFrom 4 :: [Integer] = [4,5,6,7,...]

• enumFrom 6 :: [Int] = [6,7,8,9,...,maxBound :: Int]

enumFromThen :: a -> a -> [a]

Used in Haskell's translation of [n,n'..] with [n,n'..] = enumFromThen n n', a possible implementation being enumFromThen n n' = n : n' : worker (f x) (f x n'), worker s v = v : worker s (s v), x = fromEnum n' - fromEnum n and f n y | n > 0 = f (n - 1) (succ y) | n < 0 = f (n + 1) (pred y) | otherwise = y For example:

• enumFromThen 4 6 :: [Integer] = [4,6,8,10...]

• enumFromThen 6 2 :: [Int] = [6,2,-2,-6,...,minBound :: Int]

enumFromTo :: a -> a -> [a]

Used in Haskell's translation of [n..m] with [n..m] = enumFromTo n m, a possible implementation being enumFromTo n m | n <= m = n : enumFromTo (succ n) m | otherwise = []. For example:

• enumFromTo 6 10 :: [Int] = [6,7,8,9,10]

• enumFromTo 42 1 :: [Integer] = []

enumFromThenTo :: a -> a -> a -> [a]

Used in Haskell's translation of [n,n'..m] with [n,n'..m] = enumFromThenTo n n' m, a possible implementation being enumFromThenTo n n' m = worker (f x) (c x) n m, x = fromEnum n' - fromEnum n, c x = bool (>=) ((x 0) f n y | n > 0 = f (n - 1) (succ y) | n < 0 = f (n + 1) (pred y) | otherwise = y and worker s c v m | c v m = v : worker s c (s v) m | otherwise = [] For example:

• enumFromThenTo 4 2 -6 :: [Integer] = [4,2,0,-2,-4,-6]

• enumFromThenTo 6 8 2 :: [Int] = []

Instances

Enum Associativity

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

succ :: Associativity -> Associativity

pred :: Associativity -> Associativity

toEnum :: Int -> Associativity

fromEnum :: Associativity -> Int

enumFrom :: Associativity -> [Associativity]

enumFromThen :: Associativity -> Associativity -> [Associativity]

enumFromTo :: Associativity -> Associativity -> [Associativity]

enumFromThenTo :: Associativity -> Associativity -> Associativity -> [Associativity]

Enum DecidedStrictness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

succ :: DecidedStrictness -> DecidedStrictness

pred :: DecidedStrictness -> DecidedStrictness

toEnum :: Int -> DecidedStrictness

fromEnum :: DecidedStrictness -> Int

enumFrom :: DecidedStrictness -> [DecidedStrictness]

enumFromThen :: DecidedStrictness -> DecidedStrictness -> [DecidedStrictness]

enumFromTo :: DecidedStrictness -> DecidedStrictness -> [DecidedStrictness]

enumFromThenTo :: DecidedStrictness -> DecidedStrictness -> DecidedStrictness -> [DecidedStrictness]

Enum SourceStrictness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

succ :: SourceStrictness -> SourceStrictness

pred :: SourceStrictness -> SourceStrictness

toEnum :: Int -> SourceStrictness

fromEnum :: SourceStrictness -> Int

enumFrom :: SourceStrictness -> [SourceStrictness]

enumFromThen :: SourceStrictness -> SourceStrictness -> [SourceStrictness]

enumFromTo :: SourceStrictness -> SourceStrictness -> [SourceStrictness]

enumFromThenTo :: SourceStrictness -> SourceStrictness -> SourceStrictness -> [SourceStrictness]

Enum SourceUnpackedness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

succ :: SourceUnpackedness -> SourceUnpackedness

pred :: SourceUnpackedness -> SourceUnpackedness

toEnum :: Int -> SourceUnpackedness

fromEnum :: SourceUnpackedness -> Int

enumFrom :: SourceUnpackedness -> [SourceUnpackedness]

enumFromThen :: SourceUnpackedness -> SourceUnpackedness -> [SourceUnpackedness]

enumFromTo :: SourceUnpackedness -> SourceUnpackedness -> [SourceUnpackedness]

enumFromThenTo :: SourceUnpackedness -> SourceUnpackedness -> SourceUnpackedness -> [SourceUnpackedness]

Enum 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]

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]

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]

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]

Enum Word16

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word16 -> Word16

pred :: Word16 -> Word16

toEnum :: Int -> Word16

fromEnum :: Word16 -> Int

enumFrom :: Word16 -> [Word16]

enumFromThen :: Word16 -> Word16 -> [Word16]

enumFromTo :: Word16 -> Word16 -> [Word16]

enumFromThenTo :: Word16 -> Word16 -> Word16 -> [Word16]

Enum Word32

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word32 -> Word32

pred :: Word32 -> Word32

toEnum :: Int -> Word32

fromEnum :: Word32 -> Int

enumFrom :: Word32 -> [Word32]

enumFromThen :: Word32 -> Word32 -> [Word32]

enumFromTo :: Word32 -> Word32 -> [Word32]

enumFromThenTo :: Word32 -> Word32 -> Word32 -> [Word32]

Enum Word64

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word64 -> Word64

pred :: Word64 -> Word64

toEnum :: Int -> Word64

fromEnum :: Word64 -> Int

enumFrom :: Word64 -> [Word64]

enumFromThen :: Word64 -> Word64 -> [Word64]

enumFromTo :: Word64 -> Word64 -> [Word64]

enumFromThenTo :: Word64 -> Word64 -> Word64 -> [Word64]

Enum Word8

Since: base-2.1

Defined in GHC.Word

Methods

succ :: Word8 -> Word8

pred :: Word8 -> Word8

toEnum :: Int -> Word8

fromEnum :: Word8 -> Int

enumFrom :: Word8 -> [Word8]

enumFromThen :: Word8 -> Word8 -> [Word8]

enumFromTo :: Word8 -> Word8 -> [Word8]

enumFromThenTo :: Word8 -> Word8 -> Word8 -> [Word8]

Enum 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]

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]

Enum Natural

Since: base-4.8.0.0

Defined in GHC.Enum

Methods

succ :: Natural -> Natural

pred :: Natural -> Natural

toEnum :: Int -> Natural

fromEnum :: Natural -> Int

enumFrom :: Natural -> [Natural]

enumFromThen :: Natural -> Natural -> [Natural]

enumFromTo :: Natural -> Natural -> [Natural]

enumFromThenTo :: Natural -> Natural -> Natural -> [Natural]

Enum ()

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: () -> ()

pred :: () -> ()

toEnum :: Int -> ()

fromEnum :: () -> Int

enumFrom :: () -> [()]

enumFromThen :: () -> () -> [()]

enumFromTo :: () -> () -> [()]

enumFromThenTo :: () -> () -> () -> [()]

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]

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]

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]

Enum Levity

Since: base-4.16.0.0

Defined in GHC.Enum

Methods

succ :: Levity -> Levity

pred :: Levity -> Levity

toEnum :: Int -> Levity

fromEnum :: Levity -> Int

enumFrom :: Levity -> [Levity]

enumFromThen :: Levity -> Levity -> [Levity]

enumFromTo :: Levity -> Levity -> [Levity]

enumFromThenTo :: Levity -> Levity -> Levity -> [Levity]

Enum VecCount

Since: base-4.10.0.0

Defined in GHC.Enum

Methods

succ :: VecCount -> VecCount

pred :: VecCount -> VecCount

toEnum :: Int -> VecCount

fromEnum :: VecCount -> Int

enumFrom :: VecCount -> [VecCount]

enumFromThen :: VecCount -> VecCount -> [VecCount]

enumFromTo :: VecCount -> VecCount -> [VecCount]

enumFromThenTo :: VecCount -> VecCount -> VecCount -> [VecCount]

Enum VecElem

Since: base-4.10.0.0

Defined in GHC.Enum

Methods

succ :: VecElem -> VecElem

pred :: VecElem -> VecElem

toEnum :: Int -> VecElem

fromEnum :: VecElem -> Int

enumFrom :: VecElem -> [VecElem]

enumFromThen :: VecElem -> VecElem -> [VecElem]

enumFromTo :: VecElem -> VecElem -> [VecElem]

enumFromThenTo :: VecElem -> VecElem -> VecElem -> [VecElem]

Enum Word

Since: base-2.1

Defined in GHC.Enum

Methods

succ :: Word -> Word

pred :: Word -> Word

toEnum :: Int -> Word

fromEnum :: Word -> Int

enumFrom :: Word -> [Word]

enumFromThen :: Word -> Word -> [Word]

enumFromTo :: Word -> Word -> [Word]

enumFromThenTo :: Word -> Word -> Word -> [Word]

Enum a => Enum (And a)

Since: base-4.16

Defined in Data.Bits

Methods

succ :: And a -> And a

pred :: And a -> And a

toEnum :: Int -> And a

fromEnum :: And a -> Int

enumFrom :: And a -> [And a]

enumFromThen :: And a -> And a -> [And a]

enumFromTo :: And a -> And a -> [And a]

enumFromThenTo :: And a -> And a -> And a -> [And a]

Enum a => Enum (Iff a)

Since: base-4.16

Defined in Data.Bits

Methods

succ :: Iff a -> Iff a

pred :: Iff a -> Iff a

toEnum :: Int -> Iff a

fromEnum :: Iff a -> Int

enumFrom :: Iff a -> [Iff a]

enumFromThen :: Iff a -> Iff a -> [Iff a]

enumFromTo :: Iff a -> Iff a -> [Iff a]

enumFromThenTo :: Iff a -> Iff a -> Iff a -> [Iff a]

Enum a => Enum (Ior a)

Since: base-4.16

Defined in Data.Bits

Methods

succ :: Ior a -> Ior a

pred :: Ior a -> Ior a

toEnum :: Int -> Ior a

fromEnum :: Ior a -> Int

enumFrom :: Ior a -> [Ior a]

enumFromThen :: Ior a -> Ior a -> [Ior a]

enumFromTo :: Ior a -> Ior a -> [Ior a]

enumFromThenTo :: Ior a -> Ior a -> Ior a -> [Ior a]

Enum a => Enum (Xor a)

Since: base-4.16

Defined in Data.Bits

Methods

succ :: Xor a -> Xor a

pred :: Xor a -> Xor a

toEnum :: Int -> Xor a

fromEnum :: Xor a -> Int

enumFrom :: Xor a -> [Xor a]

enumFromThen :: Xor a -> Xor a -> [Xor a]

enumFromTo :: Xor a -> Xor a -> [Xor a]

enumFromThenTo :: Xor a -> Xor a -> Xor a -> [Xor a]

Enum a => Enum (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

succ :: Identity a -> Identity a

pred :: Identity a -> Identity a

toEnum :: Int -> Identity a

fromEnum :: Identity a -> Int

enumFrom :: Identity a -> [Identity a]

enumFromThen :: Identity a -> Identity a -> [Identity a]

enumFromTo :: Identity a -> Identity a -> [Identity a]

enumFromThenTo :: Identity a -> Identity a -> Identity a -> [Identity a]

Enum a => Enum (First a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

succ :: First a -> First a

pred :: First a -> First a

toEnum :: Int -> First a

fromEnum :: First a -> Int

enumFrom :: First a -> [First a]

enumFromThen :: First a -> First a -> [First a]

enumFromTo :: First a -> First a -> [First a]

enumFromThenTo :: First a -> First a -> First a -> [First a]

Enum a => Enum (Last a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

succ :: Last a -> Last a

pred :: Last a -> Last a

toEnum :: Int -> Last a

fromEnum :: Last a -> Int

enumFrom :: Last a -> [Last a]

enumFromThen :: Last a -> Last a -> [Last a]

enumFromTo :: Last a -> Last a -> [Last a]

enumFromThenTo :: Last a -> Last a -> Last a -> [Last a]

Enum a => Enum (Max a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

succ :: Max a -> Max a

pred :: Max a -> Max a

toEnum :: Int -> Max a

fromEnum :: Max a -> Int

enumFrom :: Max a -> [Max a]

enumFromThen :: Max a -> Max a -> [Max a]

enumFromTo :: Max a -> Max a -> [Max a]

enumFromThenTo :: Max a -> Max a -> Max a -> [Max a]

Enum a => Enum (Min a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

succ :: Min a -> Min a

pred :: Min a -> Min a

toEnum :: Int -> Min a

fromEnum :: Min a -> Int

enumFrom :: Min a -> [Min a]

enumFromThen :: Min a -> Min a -> [Min a]

enumFromTo :: Min a -> Min a -> [Min a]

enumFromThenTo :: Min a -> Min a -> Min a -> [Min a]

Enum a => Enum (WrappedMonoid a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

succ :: WrappedMonoid a -> WrappedMonoid a

pred :: WrappedMonoid a -> WrappedMonoid a

toEnum :: Int -> WrappedMonoid a

fromEnum :: WrappedMonoid a -> Int

enumFrom :: WrappedMonoid a -> [WrappedMonoid a]

enumFromThen :: WrappedMonoid a -> WrappedMonoid a -> [WrappedMonoid a]

enumFromTo :: WrappedMonoid a -> WrappedMonoid a -> [WrappedMonoid a]

enumFromThenTo :: WrappedMonoid a -> WrappedMonoid a -> WrappedMonoid a -> [WrappedMonoid a]

Integral a => Enum (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

succ :: Ratio a -> Ratio a

pred :: Ratio a -> Ratio a

toEnum :: Int -> Ratio a

fromEnum :: Ratio a -> Int

enumFrom :: Ratio a -> [Ratio a]

enumFromThen :: Ratio a -> Ratio a -> [Ratio a]

enumFromTo :: Ratio a -> Ratio a -> [Ratio a]

enumFromThenTo :: Ratio a -> Ratio a -> Ratio a -> [Ratio a]

Enum a => Enum (a)

Defined in GHC.Enum

Methods

succ :: (a) -> (a)

pred :: (a) -> (a)

toEnum :: Int -> (a)

fromEnum :: (a) -> Int

enumFrom :: (a) -> [(a)]

enumFromThen :: (a) -> (a) -> [(a)]

enumFromTo :: (a) -> (a) -> [(a)]

enumFromThenTo :: (a) -> (a) -> (a) -> [(a)]

Enum (Fixed a)

Recall that, for numeric types, succ and pred typically add and subtract 1, respectively. This is not true in the case of Fixed, whose successor and predecessor functions intuitively return the "next" and "previous" values in the enumeration. The results of these functions thus depend on the resolution of the Fixed value. For example, when enumerating values of resolution 10^-3 of type Milli = Fixed E3,

  succ (0.000 :: Milli) == 0.001

and likewise

  pred (0.000 :: Milli) == -0.001

In other words, succ and pred increment and decrement a fixed-precision value by the least amount such that the value's resolution is unchanged. For example, 10^-12 is the smallest (positive) amount that can be added to a value of type Pico = Fixed E12 without changing its resolution, and so

  succ (0.000000000000 :: Pico) == 0.000000000001

and similarly

  pred (0.000000000000 :: Pico) == -0.000000000001

This is worth bearing in mind when defining Fixed arithmetic sequences. In particular, you may be forgiven for thinking the sequence

  [1..10] :: [Pico]

evaluates to [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] :: [Pico].

However, this is not true. On the contrary, similarly to the above implementations of succ and pred, enumFromTo :: Pico -> Pico -> [Pico] has a "step size" of 10^-12. Hence, the list [1..10] :: [Pico] has the form

  [1.000000000000, 1.00000000001, 1.00000000002, ..., 10.000000000000]

and contains 9 * 10^12 + 1 values.

Since: base-2.1

Defined in Data.Fixed

Methods

succ :: Fixed a -> Fixed a

pred :: Fixed a -> Fixed a

toEnum :: Int -> Fixed a

fromEnum :: Fixed a -> Int

enumFrom :: Fixed a -> [Fixed a]

enumFromThen :: Fixed a -> Fixed a -> [Fixed a]

enumFromTo :: Fixed a -> Fixed a -> [Fixed a]

enumFromThenTo :: Fixed a -> Fixed a -> Fixed a -> [Fixed a]

Enum (Proxy s)

Since: base-4.7.0.0

Defined in Data.Proxy

Methods

succ :: Proxy s -> Proxy s

pred :: Proxy s -> Proxy s

toEnum :: Int -> Proxy s

fromEnum :: Proxy s -> Int

enumFrom :: Proxy s -> [Proxy s]

enumFromThen :: Proxy s -> Proxy s -> [Proxy s]

enumFromTo :: Proxy s -> Proxy s -> [Proxy s]

enumFromThenTo :: Proxy s -> Proxy s -> Proxy s -> [Proxy s]

Enum a => Enum (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

succ :: Const a b -> Const a b

pred :: Const a b -> Const a b

toEnum :: Int -> Const a b

fromEnum :: Const a b -> Int

enumFrom :: Const a b -> [Const a b]

enumFromThen :: Const a b -> Const a b -> [Const a b]

enumFromTo :: Const a b -> Const a b -> [Const a b]

enumFromThenTo :: Const a b -> Const a b -> Const a b -> [Const a b]

Enum (f a) => Enum (Ap f a)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

succ :: Ap f a -> Ap f a

pred :: Ap f a -> Ap f a

toEnum :: Int -> Ap f a

fromEnum :: Ap f a -> Int

enumFrom :: Ap f a -> [Ap f a]

enumFromThen :: Ap f a -> Ap f a -> [Ap f a]

enumFromTo :: Ap f a -> Ap f a -> [Ap f a]

enumFromThenTo :: Ap f a -> Ap f a -> Ap f a -> [Ap f a]

a ~ b => Enum (a :~: b)

Since: base-4.7.0.0

Defined in Data.Type.Equality

Methods

succ :: (a :~: b) -> a :~: b

pred :: (a :~: b) -> a :~: b

toEnum :: Int -> a :~: b

fromEnum :: (a :~: b) -> Int

enumFrom :: (a :~: b) -> [a :~: b]

enumFromThen :: (a :~: b) -> (a :~: b) -> [a :~: b]

enumFromTo :: (a :~: b) -> (a :~: b) -> [a :~: b]

enumFromThenTo :: (a :~: b) -> (a :~: b) -> (a :~: b) -> [a :~: b]

a ~~ b => Enum (a :~~: b)

Since: base-4.10.0.0

Defined in Data.Type.Equality

Methods

succ :: (a :~~: b) -> a :~~: b

pred :: (a :~~: b) -> a :~~: b

toEnum :: Int -> a :~~: b

fromEnum :: (a :~~: b) -> Int

enumFrom :: (a :~~: b) -> [a :~~: b]

enumFromThen :: (a :~~: b) -> (a :~~: b) -> [a :~~: b]

enumFromTo :: (a :~~: b) -> (a :~~: b) -> [a :~~: b]

enumFromThenTo :: (a :~~: b) -> (a :~~: b) -> (a :~~: b) -> [a :~~: b]

error :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => [Char] -> a

error stops execution and displays an error message.

undefined :: forall (r :: RuntimeRep) (a :: TYPE r). 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 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.

Constructors

F# Float#

Instances

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

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

Read Float

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Float

readList :: ReadS [Float]

readPrec :: ReadPrec Float

readListPrec :: ReadPrec [Float]

Default Float

Defined in Data.Default.Class

Methods

def :: Float

Eq Float

Note that due to the presence of NaN, Float's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Float)
False

Also note that Float's Eq instance does not satisfy extensionality:

>>> 0 == (-0 :: Float)
True
>>> recip 0 == recip (-0 :: Float)
False

Defined in GHC.Classes

Methods

(==) :: Float -> Float -> Bool

(/=) :: Float -> Float -> Bool

Ord Float

Note that due to the presence of NaN, Float's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Float)
False

Also note that, due to the same, Ord's operator interactions are not respected by Float's instance:

>>> (0/0 :: Float) > 1
False
>>> compare (0/0 :: Float) 1
GT

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

Generic1 (URec Float :: k -> Type)

Defined in GHC.Generics

Associated Types

type Rep1 (URec Float) :: k -> Type

Methods

from1 :: forall (a :: k0). URec Float a -> Rep1 (URec Float) a

to1 :: forall (a :: k0). Rep1 (URec Float) a -> URec Float a

Foldable (UFloat :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => UFloat m -> m

foldMap :: Monoid m => (a -> m) -> UFloat a -> m

foldMap' :: Monoid m => (a -> m) -> UFloat a -> m

foldr :: (a -> b -> b) -> b -> UFloat a -> b

foldr' :: (a -> b -> b) -> b -> UFloat a -> b

foldl :: (b -> a -> b) -> b -> UFloat a -> b

foldl' :: (b -> a -> b) -> b -> UFloat a -> b

foldr1 :: (a -> a -> a) -> UFloat a -> a

foldl1 :: (a -> a -> a) -> UFloat a -> a

toList :: UFloat a -> [a]

null :: UFloat a -> Bool

length :: UFloat a -> Int

elem :: Eq a => a -> UFloat a -> Bool

maximum :: Ord a => UFloat a -> a

minimum :: Ord a => UFloat a -> a

sum :: Num a => UFloat a -> a

product :: Num a => UFloat a -> a

Traversable (UFloat :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UFloat a -> f (UFloat b)

sequenceA :: Applicative f => UFloat (f a) -> f (UFloat a)

mapM :: Monad m => (a -> m b) -> UFloat a -> m (UFloat b)

sequence :: Monad m => UFloat (m a) -> m (UFloat a)

Functor (URec Float :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Float a -> URec Float b

(<$) :: a -> URec Float b -> URec Float a

Generic (URec Float p)

Defined in GHC.Generics

Associated Types

type Rep (URec Float p) :: Type -> Type

Methods

from :: URec Float p -> Rep (URec Float p) x

to :: Rep (URec Float p) x -> URec Float p

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

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

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 -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

type Rep1 (URec Float :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UFloat" 'PrefixI 'True) (S1 ('MetaSel ('Just "uFloat#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UFloat :: k -> Type)))

type Rep (URec Float p)

Defined in GHC.Generics

type Rep (URec Float p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UFloat" 'PrefixI 'True) (S1 ('MetaSel ('Just "uFloat#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UFloat :: Type -> Type)))

data Double

Double-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE double-precision type.

Constructors

D# Double#

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

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

Read Double

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Double

readList :: ReadS [Double]

readPrec :: ReadPrec Double

readListPrec :: ReadPrec [Double]

Default Double

Defined in Data.Default.Class

Methods

def :: Double

Eq Double

Note that due to the presence of NaN, Double's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Double)
False

Also note that Double's Eq instance does not satisfy substitutivity:

>>> 0 == (-0 :: Double)
True
>>> recip 0 == recip (-0 :: Double)
False

Defined in GHC.Classes

Methods

(==) :: Double -> Double -> Bool

(/=) :: Double -> Double -> Bool

Ord Double

Note that due to the presence of NaN, Double's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Double)
False

Also note that, due to the same, Ord's operator interactions are not respected by Double's instance:

>>> (0/0 :: Double) > 1
False
>>> compare (0/0 :: Double) 1
GT

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

Generic1 (URec Double :: k -> Type)

Defined in GHC.Generics

Associated Types

type Rep1 (URec Double) :: k -> Type

Methods

from1 :: forall (a :: k0). URec Double a -> Rep1 (URec Double) a

to1 :: forall (a :: k0). Rep1 (URec Double) a -> URec Double a

Foldable (UDouble :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Foldable

Methods

fold :: Monoid m => UDouble m -> m

foldMap :: Monoid m => (a -> m) -> UDouble a -> m

foldMap' :: Monoid m => (a -> m) -> UDouble a -> m

foldr :: (a -> b -> b) -> b -> UDouble a -> b

foldr' :: (a -> b -> b) -> b -> UDouble a -> b

foldl :: (b -> a -> b) -> b -> UDouble a -> b

foldl' :: (b -> a -> b) -> b -> UDouble a -> b

foldr1 :: (a -> a -> a) -> UDouble a -> a

foldl1 :: (a -> a -> a) -> UDouble a -> a

toList :: UDouble a -> [a]

null :: UDouble a -> Bool

length :: UDouble a -> Int

elem :: Eq a => a -> UDouble a -> Bool

maximum :: Ord a => UDouble a -> a

minimum :: Ord a => UDouble a -> a

sum :: Num a => UDouble a -> a

product :: Num a => UDouble a -> a

Traversable (UDouble :: Type -> Type)

Since: base-4.9.0.0

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UDouble a -> f (UDouble b)

sequenceA :: Applicative f => UDouble (f a) -> f (UDouble a)

mapM :: Monad m => (a -> m b) -> UDouble a -> m (UDouble b)

sequence :: Monad m => UDouble (m a) -> m (UDouble a)

Functor (URec Double :: Type -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Double a -> URec Double b

(<$) :: a -> URec Double b -> URec Double a

Generic (URec Double p)

Defined in GHC.Generics

Associated Types

type Rep (URec Double p) :: Type -> Type

Methods

from :: URec Double p -> Rep (URec Double p) x

to :: Rep (URec Double p) x -> URec Double p

Show (URec Double p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> URec Double p -> ShowS

show :: URec Double p -> String

showList :: [URec Double p] -> ShowS

Eq (URec Double p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

(==) :: URec Double p -> URec Double p -> Bool

(/=) :: URec Double p -> URec Double p -> Bool

Ord (URec Double p)

Since: base-4.9.0.0

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

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 -> Type)

Since: base-4.9.0.0

Defined in GHC.Generics

type Rep1 (URec Double :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UDouble" 'PrefixI 'True) (S1 ('MetaSel ('Just "uDouble#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UDouble :: k -> Type)))

type Rep (URec Double p)

Since: base-4.9.0.0

Defined in GHC.Generics

type Rep (URec Double p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UDouble" 'PrefixI 'True) (S1 ('MetaSel ('Just "uDouble#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UDouble :: Type -> Type)))

class Generic a

Representable types of kind *. This class is derivable in GHC with the DeriveGeneric flag on.

A Generic instance must satisfy the following laws:

from . to ≡ id
to . from ≡ id

Minimal complete definition

from, to

Instances

Generic Void

Defined in Data.Void

Associated Types

type Rep Void :: Type -> Type

Methods

from :: Void -> Rep Void x

to :: Rep Void x -> Void

Generic Fingerprint

Defined in GHC.Generics

Associated Types

type Rep Fingerprint :: Type -> Type

Methods

from :: Fingerprint -> Rep Fingerprint x

to :: Rep Fingerprint x -> Fingerprint

Generic Associativity

Defined in GHC.Generics

Associated Types

type Rep Associativity :: Type -> Type

Methods

from :: Associativity -> Rep Associativity x

to :: Rep Associativity x -> Associativity

Generic DecidedStrictness

Defined in GHC.Generics

Associated Types

type Rep DecidedStrictness :: Type -> Type

Methods

from :: DecidedStrictness -> Rep DecidedStrictness x

to :: Rep DecidedStrictness x -> DecidedStrictness

Generic Fixity

Defined in GHC.Generics

Associated Types

type Rep Fixity :: Type -> Type

Methods

from :: Fixity -> Rep Fixity x

to :: Rep Fixity x -> Fixity

Generic SourceStrictness

Defined in GHC.Generics

Associated Types

type Rep SourceStrictness :: Type -> Type

Methods

from :: SourceStrictness -> Rep SourceStrictness x

to :: Rep SourceStrictness x -> SourceStrictness

Generic SourceUnpackedness

Defined in GHC.Generics

Associated Types

type Rep SourceUnpackedness :: Type -> Type

Methods

from :: SourceUnpackedness -> Rep SourceUnpackedness x

to :: Rep SourceUnpackedness x -> SourceUnpackedness

Generic SrcLoc

Defined in GHC.Generics

Associated Types

type Rep SrcLoc :: Type -> Type

Methods

from :: SrcLoc -> Rep SrcLoc x

to :: Rep SrcLoc x -> SrcLoc

Generic GeneralCategory

Defined in GHC.Generics

Associated Types

type Rep GeneralCategory :: Type -> Type

Methods

from :: GeneralCategory -> Rep GeneralCategory x

to :: Rep GeneralCategory x -> GeneralCategory

Generic Ordering

Defined in GHC.Generics

Associated Types

type Rep Ordering :: Type -> Type

Methods

from :: Ordering -> Rep Ordering x

to :: Rep Ordering x -> Ordering

Generic ()

Defined in GHC.Generics

Associated Types

type Rep () :: Type -> Type

Methods

from :: () -> Rep () x

to :: Rep () x -> ()

Generic Bool

Defined in GHC.Generics

Associated Types

type Rep Bool :: Type -> Type

Methods

from :: Bool -> Rep Bool x

to :: Rep Bool x -> Bool

Generic (ZipList a)

Defined in Control.Applicative

Associated Types

type Rep (ZipList a) :: Type -> Type

Methods

from :: ZipList a -> Rep (ZipList a) x

to :: Rep (ZipList a) x -> ZipList a

Generic (Complex a)

Defined in Data.Complex

Associated Types

type Rep (Complex a) :: Type -> Type

Methods

from :: Complex a -> Rep (Complex a) x

to :: Rep (Complex a) x -> Complex a

Generic (Identity a)

Defined in Data.Functor.Identity

Associated Types

type Rep (Identity a) :: Type -> Type

Methods

from :: Identity a -> Rep (Identity a) x

to :: Rep (Identity a) x -> Identity a

Generic (First a)

Defined in Data.Monoid

Associated Types

type Rep (First a) :: Type -> Type

Methods

from :: First a -> Rep (First a) x

to :: Rep (First a) x -> First a

Generic (Last a)

Defined in Data.Monoid

Associated Types

type Rep (Last a) :: Type -> Type

Methods

from :: Last a -> Rep (Last a) x

to :: Rep (Last a) x -> Last a

Generic (Down a)

Defined in GHC.Generics

Associated Types

type Rep (Down a) :: Type -> Type

Methods

from :: Down a -> Rep (Down a) x

to :: Rep (Down a) x -> Down a

Generic (First a)

Defined in Data.Semigroup

Associated Types

type Rep (First a) :: Type -> Type

Methods

from :: First a -> Rep (First a) x

to :: Rep (First a) x -> First a

Generic (Last a)

Defined in Data.Semigroup

Associated Types

type Rep (Last a) :: Type -> Type

Methods

from :: Last a -> Rep (Last a) x

to :: Rep (Last a) x -> Last a

Generic (Max a)

Defined in Data.Semigroup

Associated Types

type Rep (Max a) :: Type -> Type

Methods

from :: Max a -> Rep (Max a) x

to :: Rep (Max a) x -> Max a

Generic (Min a)

Defined in Data.Semigroup

Associated Types

type Rep (Min a) :: Type -> Type

Methods

from :: Min a -> Rep (Min a) x

to :: Rep (Min a) x -> Min a

Generic (WrappedMonoid m)

Defined in Data.Semigroup

Associated Types

type Rep (WrappedMonoid m) :: Type -> Type

Methods

from :: WrappedMonoid m -> Rep (WrappedMonoid m) x

to :: Rep (WrappedMonoid m) x -> WrappedMonoid m

Generic (Par1 p)

Defined in GHC.Generics

Associated Types

type Rep (Par1 p) :: Type -> Type

Methods

from :: Par1 p -> Rep (Par1 p) x

to :: Rep (Par1 p) x -> Par1 p

Generic (Digit a)

Defined in Data.Sequence.Internal

Associated Types

type Rep (Digit a) :: Type -> Type

Methods

from :: Digit a -> Rep (Digit a) x

to :: Rep (Digit a) x -> Digit a

Generic (Elem a)

Defined in Data.Sequence.Internal

Associated Types

type Rep (Elem a) :: Type -> Type

Methods

from :: Elem a -> Rep (Elem a) x

to :: Rep (Elem a) x -> Elem a

Generic (FingerTree a)

Defined in Data.Sequence.Internal

Associated Types

type Rep (FingerTree a) :: Type -> Type

Methods

from :: FingerTree a -> Rep (FingerTree a) x

to :: Rep (FingerTree a) x -> FingerTree a

Generic (Node a)

Defined in Data.Sequence.Internal

Associated Types

type Rep (Node a) :: Type -> Type

Methods

from :: Node a -> Rep (Node a) x

to :: Rep (Node a) x -> Node a

Generic (ViewL a)

Defined in Data.Sequence.Internal

Associated Types

type Rep (ViewL a) :: Type -> Type

Methods

from :: ViewL a -> Rep (ViewL a) x

to :: Rep (ViewL a) x -> ViewL a

Generic (ViewR a)

Defined in Data.Sequence.Internal

Associated Types

type Rep (ViewR a) :: Type -> Type

Methods

from :: ViewR a -> Rep (ViewR a) x

to :: Rep (ViewR a) x -> ViewR a

Generic (NonEmpty a)

Defined in GHC.Generics

Associated Types

type Rep (NonEmpty a) :: Type -> Type

Methods

from :: NonEmpty a -> Rep (NonEmpty a) x

to :: Rep (NonEmpty a) x -> NonEmpty a

Generic (Maybe a)

Defined in GHC.Generics

Associated Types

type Rep (Maybe a) :: Type -> Type

Methods

from :: Maybe a -> Rep (Maybe a) x

to :: Rep (Maybe a) x -> Maybe a

Generic (a)

Defined in GHC.Generics

Associated Types

type Rep (a) :: Type -> Type

Methods

from :: (a) -> Rep (a) x

to :: Rep (a) x -> (a)

Generic [a]

Defined in GHC.Generics

Associated Types

type Rep [a] :: Type -> Type

Methods

from :: [a] -> Rep [a] x

to :: Rep [a] x -> [a]

Generic (WrappedMonad m a)

Defined in Control.Applicative

Associated Types

type Rep (WrappedMonad m a) :: Type -> Type

Methods

from :: WrappedMonad m a -> Rep (WrappedMonad m a) x

to :: Rep (WrappedMonad m a) x -> WrappedMonad m a

Generic (Either a b)

Defined in GHC.Generics

Associated Types

type Rep (Either a b) :: Type -> Type

Methods

from :: Either a b -> Rep (Either a b) x

to :: Rep (Either a b) x -> Either a b

Generic (Proxy t)

Defined in GHC.Generics

Associated Types

type Rep (Proxy t) :: Type -> Type

Methods

from :: Proxy t -> Rep (Proxy t) x

to :: Rep (Proxy t) x -> Proxy t

Generic (Arg a b)

Defined in Data.Semigroup

Associated Types

type Rep (Arg a b) :: Type -> Type

Methods

from :: Arg a b -> Rep (Arg a b) x

to :: Rep (Arg a b) x -> Arg a b

Generic (U1 p)

Defined in GHC.Generics

Associated Types

type Rep (U1 p) :: Type -> Type

Methods

from :: U1 p -> Rep (U1 p) x

to :: Rep (U1 p) x -> U1 p

Generic (V1 p)

Defined in GHC.Generics

Associated Types

type Rep (V1 p) :: Type -> Type

Methods

from :: V1 p -> Rep (V1 p) x

to :: Rep (V1 p) x -> V1 p

Generic (a, b)

Defined in GHC.Generics

Associated Types

type Rep (a, b) :: Type -> Type

Methods

from :: (a, b) -> Rep (a, b) x

to :: Rep (a, b) x -> (a, b)

Generic (WrappedArrow a b c)

Defined in Control.Applicative

Associated Types

type Rep (WrappedArrow a b c) :: Type -> Type

Methods

from :: WrappedArrow a b c -> Rep (WrappedArrow a b c) x

to :: Rep (WrappedArrow a b c) x -> WrappedArrow a b c

Generic (Kleisli m a b)

Defined in Control.Arrow

Associated Types

type Rep (Kleisli m a b) :: Type -> Type

Methods

from :: Kleisli m a b -> Rep (Kleisli m a b) x

to :: Rep (Kleisli m a b) x -> Kleisli m a b

Generic (Const a b)

Defined in Data.Functor.Const

Associated Types

type Rep (Const a b) :: Type -> Type

Methods

from :: Const a b -> Rep (Const a b) x

to :: Rep (Const a b) x -> Const a b

Generic (Ap f a)

Defined in Data.Monoid

Associated Types

type Rep (Ap f a) :: Type -> Type

Methods

from :: Ap f a -> Rep (Ap f a) x

to :: Rep (Ap f a) x -> Ap f a

Generic (Rec1 f p)

Defined in GHC.Generics

Associated Types

type Rep (Rec1 f p) :: Type -> Type

Methods

from :: Rec1 f p -> Rep (Rec1 f p) x

to :: Rep (Rec1 f p) x -> Rec1 f p

Generic (URec (Ptr ()) p)

Defined in GHC.Generics

Associated Types

type Rep (URec (Ptr ()) p) :: Type -> Type

Methods

from :: URec (Ptr ()) p -> Rep (URec (Ptr ()) p) x

to :: Rep (URec (Ptr ()) p) x -> URec (Ptr ()) p

Generic (URec Char p)

Defined in GHC.Generics

Associated Types

type Rep (URec Char p) :: Type -> Type

Methods

from :: URec Char p -> Rep (URec Char p) x

to :: Rep (URec Char p) x -> URec Char p

Generic (URec Double p)

Defined in GHC.Generics

Associated Types

type Rep (URec Double p) :: Type -> Type

Methods

from :: URec Double p -> Rep (URec Double p) x

to :: Rep (URec Double p) x -> URec Double p

Generic (URec Float p)

Defined in GHC.Generics

Associated Types

type Rep (URec Float p) :: Type -> Type

Methods

from :: URec Float p -> Rep (URec Float p) x

to :: Rep (URec Float p) x -> URec Float p

Generic (URec Int p)

Defined in GHC.Generics

Associated Types

type Rep (URec Int p) :: Type -> Type

Methods

from :: URec Int p -> Rep (URec Int p) x

to :: Rep (URec Int p) x -> URec Int p

Generic (URec Word p)

Defined in GHC.Generics

Associated Types

type Rep (URec Word p) :: Type -> Type

Methods

from :: URec Word p -> Rep (URec Word p) x

to :: Rep (URec Word p) x -> URec Word p

Generic (a, b, c)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c) :: Type -> Type

Methods

from :: (a, b, c) -> Rep (a, b, c) x

to :: Rep (a, b, c) x -> (a, b, c)

Generic (Product f g a)

Defined in Data.Functor.Product

Associated Types

type Rep (Product f g a) :: Type -> Type

Methods

from :: Product f g a -> Rep (Product f g a) x

to :: Rep (Product f g a) x -> Product f g a

Generic (Sum f g a)

Defined in Data.Functor.Sum

Associated Types

type Rep (Sum f g a) :: Type -> Type

Methods

from :: Sum f g a -> Rep (Sum f g a) x

to :: Rep (Sum f g a) x -> Sum f g a

Generic ((f :*: g) p)

Defined in GHC.Generics

Associated Types

type Rep ((f :*: g) p) :: Type -> Type

Methods

from :: (f :*: g) p -> Rep ((f :*: g) p) x

to :: Rep ((f :*: g) p) x -> (f :*: g) p

Generic ((f :+: g) p)

Defined in GHC.Generics

Associated Types

type Rep ((f :+: g) p) :: Type -> Type

Methods

from :: (f :+: g) p -> Rep ((f :+: g) p) x

to :: Rep ((f :+: g) p) x -> (f :+: g) p

Generic (K1 i c p)

Defined in GHC.Generics

Associated Types

type Rep (K1 i c p) :: Type -> Type

Methods

from :: K1 i c p -> Rep (K1 i c p) x

to :: Rep (K1 i c p) x -> K1 i c p

Generic (a, b, c, d)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d) :: Type -> Type

Methods

from :: (a, b, c, d) -> Rep (a, b, c, d) x

to :: Rep (a, b, c, d) x -> (a, b, c, d)

Generic (Compose f g a)

Defined in Data.Functor.Compose

Associated Types

type Rep (Compose f g a) :: Type -> Type

Methods

from :: Compose f g a -> Rep (Compose f g a) x

to :: Rep (Compose f g a) x -> Compose f g a

Generic ((f :.: g) p)

Defined in GHC.Generics

Associated Types

type Rep ((f :.: g) p) :: Type -> Type

Methods

from :: (f :.: g) p -> Rep ((f :.: g) p) x

to :: Rep ((f :.: g) p) x -> (f :.: g) p

Generic (M1 i c f p)

Defined in GHC.Generics

Associated Types

type Rep (M1 i c f p) :: Type -> Type

Methods

from :: M1 i c f p -> Rep (M1 i c f p) x

to :: Rep (M1 i c f p) x -> M1 i c f p

Generic (a, b, c, d, e)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e) :: Type -> Type

Methods

from :: (a, b, c, d, e) -> Rep (a, b, c, d, e) x

to :: Rep (a, b, c, d, e) x -> (a, b, c, d, e)

Generic (a, b, c, d, e, f)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f) :: Type -> Type

Methods

from :: (a, b, c, d, e, f) -> Rep (a, b, c, d, e, f) x

to :: Rep (a, b, c, d, e, f) x -> (a, b, c, d, e, f)

Generic (a, b, c, d, e, f, g)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f, g) :: Type -> Type

Methods

from :: (a, b, c, d, e, f, g) -> Rep (a, b, c, d, e, f, g) x

to :: Rep (a, b, c, d, e, f, g) x -> (a, b, c, d, e, f, g)

Generic (a, b, c, d, e, f, g, h)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f, g, h) :: Type -> Type

Methods

from :: (a, b, c, d, e, f, g, h) -> Rep (a, b, c, d, e, f, g, h) x

to :: Rep (a, b, c, d, e, f, g, h) x -> (a, b, c, d, e, f, g, h)

Generic (a, b, c, d, e, f, g, h, i)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f, g, h, i) :: Type -> Type

Methods

from :: (a, b, c, d, e, f, g, h, i) -> Rep (a, b, c, d, e, f, g, h, i) x

to :: Rep (a, b, c, d, e, f, g, h, i) x -> (a, b, c, d, e, f, g, h, i)

Generic (a, b, c, d, e, f, g, h, i, j)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f, g, h, i, j) :: Type -> Type

Methods

from :: (a, b, c, d, e, f, g, h, i, j) -> Rep (a, b, c, d, e, f, g, h, i, j) x

to :: Rep (a, b, c, d, e, f, g, h, i, j) x -> (a, b, c, d, e, f, g, h, i, j)

Generic (a, b, c, d, e, f, g, h, i, j, k)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f, g, h, i, j, k) :: Type -> Type

Methods

from :: (a, b, c, d, e, f, g, h, i, j, k) -> Rep (a, b, c, d, e, f, g, h, i, j, k) x

to :: Rep (a, b, c, d, e, f, g, h, i, j, k) x -> (a, b, c, d, e, f, g, h, i, j, k)

Generic (a, b, c, d, e, f, g, h, i, j, k, l)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f, g, h, i, j, k, l) :: Type -> Type

Methods

from :: (a, b, c, d, e, f, g, h, i, j, k, l) -> Rep (a, b, c, d, e, f, g, h, i, j, k, l) x

to :: Rep (a, b, c, d, e, f, g, h, i, j, k, l) x -> (a, b, c, d, e, f, g, h, i, j, k, l)

Generic (a, b, c, d, e, f, g, h, i, j, k, l, m)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f, g, h, i, j, k, l, m) :: Type -> Type

Methods

from :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Rep (a, b, c, d, e, f, g, h, i, j, k, l, m) x

to :: Rep (a, b, c, d, e, f, g, h, i, j, k, l, m) x -> (a, b, c, d, e, f, g, h, i, j, k, l, m)

Generic (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f, g, h, i, j, k, l, m, n) :: Type -> Type

Methods

from :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Rep (a, b, c, d, e, f, g, h, i, j, k, l, m, n) x

to :: Rep (a, b, c, d, e, f, g, h, i, j, k, l, m, n) x -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

Generic (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

Defined in GHC.Generics

Associated Types

type Rep (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) :: Type -> Type

Methods

from :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Rep (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) x

to :: Rep (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) x -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

data Integer

Arbitrary precision integers. In contrast with fixed-size integral types such as Int, the Integer type represents the entire infinite range of integers.

Integers are stored in a kind of sign-magnitude form, hence do not expect two's complement form when using bit operations.

If the value is small (fit into an Int), IS constructor is used. Otherwise Integer and IN constructors are used to store a BigNat representing respectively the positive or the negative value magnitude.

Invariant: Integer and IN are used iff value doesn't fit in IS

Instances

Bits Integer

Since: base-2.1

Defined in GHC.Bits

Methods

(.&.) :: Integer -> Integer -> Integer

(.|.) :: Integer -> Integer -> Integer

xor :: Integer -> Integer -> Integer

complement :: Integer -> Integer

shift :: Integer -> Int -> Integer

rotate :: Integer -> Int -> Integer

zeroBits :: Integer

bit :: Int -> Integer

setBit :: Integer -> Int -> Integer

clearBit :: Integer -> Int -> Integer

complementBit :: Integer -> Int -> Integer

testBit :: Integer -> Int -> Bool

bitSizeMaybe :: Integer -> Maybe Int

bitSize :: Integer -> Int

isSigned :: Integer -> Bool

shiftL :: Integer -> Int -> Integer

unsafeShiftL :: Integer -> Int -> Integer

shiftR :: Integer -> Int -> Integer

unsafeShiftR :: Integer -> Int -> Integer

rotateL :: Integer -> Int -> Integer

rotateR :: Integer -> Int -> Integer

popCount :: Integer -> Int

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]

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

Read Integer

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Integer

readList :: ReadS [Integer]

readPrec :: ReadPrec Integer

readListPrec :: ReadPrec [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

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

Default Integer

Defined in Data.Default.Class

Methods

def :: Integer

Eq Integer

Defined in GHC.Num.Integer

Methods

(==) :: Integer -> Integer -> Bool

(/=) :: Integer -> Integer -> Bool

Ord Integer

Defined in GHC.Num.Integer

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

class Num a where

Basic numeric class.

The Haskell Report defines no laws for Num. However, (+) and (*) are customarily expected to define a ring and have the following properties:

Associativity of (+)

(x + y) + z = x + (y + z)

Commutativity of (+)

x + y = y + x

fromInteger 0 is the additive identity

x + fromInteger 0 = x

negate gives the additive inverse

x + negate x = fromInteger 0

Associativity of (*)

(x * y) * z = x * (y * z)

fromInteger 1 is the multiplicative identity

x * fromInteger 1 = x and fromInteger 1 * x = x

Distributivity of (*) with respect to (+)

a * (b + c) = (a * b) + (a * c) and (b + c) * a = (b * a) + (c * a)

Note that it isn't customarily expected that a type instance of both Num and Ord implement an ordered ring. Indeed, in base only Integer and Rational do.

Minimal complete definition

(+), (*), abs, signum, fromInteger, (negate | (-))

Methods

(+) :: a -> a -> a infixl 6

(-) :: a -> a -> a infixl 6

(*) :: a -> a -> a infixl 7

negate :: a -> a

Unary negation.

abs :: a -> a

Absolute value.

signum :: a -> a

Sign of a number. The functions abs and signum should satisfy the law:

abs x * signum x == x

For real numbers, the signum is either -1 (negative), 0 (zero) or 1 (positive).

fromInteger :: Integer -> a

Conversion from an Integer. An integer literal represents the application of the function fromInteger to the appropriate value of type Integer, so such literals have type (Num a) => a.

Instances

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 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 Word16

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word16 -> Word16 -> Word16

(-) :: Word16 -> Word16 -> Word16

(*) :: Word16 -> Word16 -> Word16

negate :: Word16 -> Word16

abs :: Word16 -> Word16

signum :: Word16 -> Word16

fromInteger :: Integer -> Word16

Num Word32

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word32 -> Word32 -> Word32

(-) :: Word32 -> Word32 -> Word32

(*) :: Word32 -> Word32 -> Word32

negate :: Word32 -> Word32

abs :: Word32 -> Word32

signum :: Word32 -> Word32

fromInteger :: Integer -> Word32

Num Word64

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word64 -> Word64 -> Word64

(-) :: Word64 -> Word64 -> Word64

(*) :: Word64 -> Word64 -> Word64

negate :: Word64 -> Word64

abs :: Word64 -> Word64

signum :: Word64 -> Word64

fromInteger :: Integer -> Word64

Num Word8

Since: base-2.1

Defined in GHC.Word

Methods

(+) :: Word8 -> Word8 -> Word8

(-) :: Word8 -> Word8 -> Word8

(*) :: Word8 -> Word8 -> Word8

negate :: Word8 -> Word8

abs :: Word8 -> Word8

signum :: Word8 -> Word8

fromInteger :: Integer -> Word8

Num 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 Natural

Note that Natural's Num instance isn't a ring: no element but 0 has an additive inverse. It is a semiring though.

Since: base-4.8.0.0

Defined in GHC.Num

Methods

(+) :: Natural -> Natural -> Natural

(-) :: Natural -> Natural -> Natural

(*) :: Natural -> Natural -> Natural

negate :: Natural -> Natural

abs :: Natural -> Natural

signum :: Natural -> Natural

fromInteger :: Integer -> Natural

Num 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 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

RealFloat a => Num (Complex a)

Since: base-2.1

Defined in Data.Complex

Methods

(+) :: Complex a -> Complex a -> Complex a

(-) :: Complex a -> Complex a -> Complex a

(*) :: Complex a -> Complex a -> Complex a

negate :: Complex a -> Complex a

abs :: Complex a -> Complex a

signum :: Complex a -> Complex a

fromInteger :: Integer -> Complex a

Num a => Num (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

(+) :: Identity a -> Identity a -> Identity a

(-) :: Identity a -> Identity a -> Identity a

(*) :: Identity a -> Identity a -> Identity a

negate :: Identity a -> Identity a

abs :: Identity a -> Identity a

signum :: Identity a -> Identity a

fromInteger :: Integer -> Identity a

Num a => Num (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 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 (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

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

HasResolution a => Num (Fixed a)

Since: base-2.1

Defined in Data.Fixed

Methods

(+) :: Fixed a -> Fixed a -> Fixed a

(-) :: Fixed a -> Fixed a -> Fixed a

(*) :: Fixed a -> Fixed a -> Fixed a

negate :: Fixed a -> Fixed a

abs :: Fixed a -> Fixed a

signum :: Fixed a -> Fixed a

fromInteger :: Integer -> Fixed a

Num a => Num (Op a b)

Defined in Data.Functor.Contravariant

Methods

(+) :: Op a b -> Op a b -> Op a b

(-) :: Op a b -> Op a b -> Op a b

(*) :: Op a b -> Op a b -> Op a b

negate :: Op a b -> Op a b

abs :: Op a b -> Op a b

signum :: Op a b -> Op a b

fromInteger :: Integer -> Op a b

Num a => Num (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

(+) :: Const a b -> Const a b -> Const a b

(-) :: Const a b -> Const a b -> Const a b

(*) :: Const a b -> Const a b -> Const a b

negate :: Const a b -> Const a b

abs :: Const a b -> Const a b

signum :: Const a b -> Const a b

fromInteger :: Integer -> Const a b

(Applicative f, Num a) => Num (Ap f a)

Note that even if the underlying Num and Applicative instances are lawful, for most Applicatives, this instance will not be lawful. If you use this instance with the list Applicative, the following customary laws will not hold:

Commutativity:

>>> Ap [10,20] + Ap [1,2]
Ap {getAp = [11,12,21,22]}
>>> Ap [1,2] + Ap [10,20]
Ap {getAp = [11,21,12,22]}

Additive inverse:

>>> Ap [] + negate (Ap [])
Ap {getAp = []}
>>> fromInteger 0 :: Ap [] Int
Ap {getAp = [0]}

Distributivity:

>>> Ap [1,2] * (3 + 4)
Ap {getAp = [7,14]}
>>> (Ap [1,2] * 3) + (Ap [1,2] * 4)
Ap {getAp = [7,11,10,14]}

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

(+) :: Ap f a -> Ap f a -> Ap f a

(-) :: Ap f a -> Ap f a -> Ap f a

(*) :: Ap f a -> Ap f a -> Ap f a

negate :: Ap f a -> Ap f a

abs :: Ap f a -> Ap f a

signum :: Ap f a -> Ap f a

fromInteger :: Integer -> Ap f a

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.

class IsLabel (x :: Symbol) a where

Methods

fromLabel :: a

type Rational = Ratio Integer

Arbitrary-precision rational numbers, represented as a ratio of two Integer values. A rational number may be constructed using the % operator.

class Num a => Fractional a where

Fractional numbers, supporting real division.

The Haskell Report defines no laws for Fractional. However, (+) and (*) are customarily expected to define a division ring and have the following properties:

recip gives the multiplicative inverse

x * recip x = recip x * x = fromInteger 1

Note that it isn't customarily expected that a type instance of Fractional implement a field. However, all instances in base do.

Methods

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

RealFloat a => Fractional (Complex a)

Since: base-2.1

Defined in Data.Complex

Methods

(/) :: Complex a -> Complex a -> Complex a

recip :: Complex a -> Complex a

fromRational :: Rational -> Complex a

Fractional a => Fractional (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

(/) :: Identity a -> Identity a -> Identity a

recip :: Identity a -> Identity a

fromRational :: Rational -> Identity a

Fractional a => Fractional (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

(/) :: Down a -> Down a -> Down a

recip :: Down a -> Down a

fromRational :: Rational -> Down a

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

HasResolution a => Fractional (Fixed a)

Since: base-2.1

Defined in Data.Fixed

Methods

(/) :: Fixed a -> Fixed a -> Fixed a

recip :: Fixed a -> Fixed a

fromRational :: Rational -> Fixed a

Fractional a => Fractional (Op a b)

Defined in Data.Functor.Contravariant

Methods

(/) :: Op a b -> Op a b -> Op a b

recip :: Op a b -> Op a b

fromRational :: Rational -> Op a b

Fractional a => Fractional (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

(/) :: Const a b -> Const a b -> Const a b

recip :: Const a b -> Const a b

fromRational :: Rational -> Const a b

class (Real a, Enum a) => Integral a where

Integral numbers, supporting integer division.

The Haskell Report defines no laws for Integral. However, Integral instances are customarily expected to define a Euclidean domain and have the following properties for the div/mod and quot/rem pairs, given suitable Euclidean functions f and g:

• x = y * quot x y + rem x y with rem x y = fromInteger 0 or g (rem x y) < g y
• x = y * div x y + mod x y with mod x y = fromInteger 0 or f (mod x y) < f y

An example of a suitable Euclidean function, for Integer's instance, is abs.

Minimal complete definition

quotRem, toInteger

Methods

toInteger :: a -> Integer

conversion to Integer

Instances

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 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 Word16

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word16 -> Word16 -> Word16

rem :: Word16 -> Word16 -> Word16

div :: Word16 -> Word16 -> Word16

mod :: Word16 -> Word16 -> Word16

quotRem :: Word16 -> Word16 -> (Word16, Word16)

divMod :: Word16 -> Word16 -> (Word16, Word16)

toInteger :: Word16 -> Integer

Integral Word32

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word32 -> Word32 -> Word32

rem :: Word32 -> Word32 -> Word32

div :: Word32 -> Word32 -> Word32

mod :: Word32 -> Word32 -> Word32

quotRem :: Word32 -> Word32 -> (Word32, Word32)

divMod :: Word32 -> Word32 -> (Word32, Word32)

toInteger :: Word32 -> Integer

Integral Word64

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word64 -> Word64 -> Word64

rem :: Word64 -> Word64 -> Word64

div :: Word64 -> Word64 -> Word64

mod :: Word64 -> Word64 -> Word64

quotRem :: Word64 -> Word64 -> (Word64, Word64)

divMod :: Word64 -> Word64 -> (Word64, Word64)

toInteger :: Word64 -> Integer

Integral Word8

Since: base-2.1

Defined in GHC.Word

Methods

quot :: Word8 -> Word8 -> Word8

rem :: Word8 -> Word8 -> Word8

div :: Word8 -> Word8 -> Word8

mod :: Word8 -> Word8 -> Word8

quotRem :: Word8 -> Word8 -> (Word8, Word8)

divMod :: Word8 -> Word8 -> (Word8, Word8)

toInteger :: Word8 -> Integer

Integral 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 Natural

Since: base-4.8.0.0

Defined in GHC.Real

Methods

quot :: Natural -> Natural -> Natural

rem :: Natural -> Natural -> Natural

div :: Natural -> Natural -> Natural

mod :: Natural -> Natural -> Natural

quotRem :: Natural -> Natural -> (Natural, Natural)

divMod :: Natural -> Natural -> (Natural, Natural)

toInteger :: Natural -> Integer

Integral 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 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

Integral a => Integral (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

quot :: Identity a -> Identity a -> Identity a

rem :: Identity a -> Identity a -> Identity a

div :: Identity a -> Identity a -> Identity a

mod :: Identity a -> Identity a -> Identity a

quotRem :: Identity a -> Identity a -> (Identity a, Identity a)

divMod :: Identity a -> Identity a -> (Identity a, Identity a)

toInteger :: Identity a -> Integer

Integral a => Integral (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

quot :: Const a b -> Const a b -> Const a b

rem :: Const a b -> Const a b -> Const a b

div :: Const a b -> Const a b -> Const a b

mod :: Const a b -> Const a b -> Const a b

quotRem :: Const a b -> Const a b -> (Const a b, Const a b)

divMod :: Const a b -> Const a b -> (Const a b, Const a b)

toInteger :: Const a b -> Integer

class (Num a, Ord a) => Real a where

Methods

toRational :: a -> Rational

the rational equivalent of its real argument with full precision

Instances

Real Int16

Since: base-2.1

Defined in GHC.Int

Methods

toRational :: Int16 -> Rational

Real Int32

Since: base-2.1

Defined in GHC.Int

Methods

toRational :: Int32 -> Rational

Real Int64

Since: base-2.1

Defined in GHC.Int

Methods

toRational :: Int64 -> Rational

Real Int8

Since: base-2.1

Defined in GHC.Int

Methods

toRational :: Int8 -> Rational

Real Word16

Since: base-2.1

Defined in GHC.Word

Methods

toRational :: Word16 -> Rational

Real Word32

Since: base-2.1

Defined in GHC.Word

Methods

toRational :: Word32 -> Rational

Real Word64

Since: base-2.1

Defined in GHC.Word

Methods

toRational :: Word64 -> Rational

Real Word8

Since: base-2.1

Defined in GHC.Word

Methods

toRational :: Word8 -> Rational

Real Integer

Since: base-2.0.1

Defined in GHC.Real

Methods

toRational :: Integer -> Rational

Real Natural

Since: base-4.8.0.0

Defined in GHC.Real

Methods

toRational :: Natural -> Rational

Real Int

Since: base-2.0.1

Defined in GHC.Real

Methods

toRational :: Int -> Rational

Real Word

Since: base-2.1

Defined in GHC.Real

Methods

toRational :: Word -> Rational

Real a => Real (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

toRational :: Identity a -> Rational

Real a => Real (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

toRational :: Down a -> Rational

Integral a => Real (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

toRational :: Ratio a -> Rational

HasResolution a => Real (Fixed a)

Since: base-2.1

Defined in Data.Fixed

Methods

toRational :: Fixed a -> Rational

Real a => Real (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

toRational :: Const a b -> Rational

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

RealFrac a => RealFrac (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

properFraction :: Integral b => Identity a -> (b, Identity a)

truncate :: Integral b => Identity a -> b

round :: Integral b => Identity a -> b

ceiling :: Integral b => Identity a -> b

floor :: Integral b => Identity a -> b

RealFrac a => RealFrac (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

properFraction :: Integral b => Down a -> (b, Down a)

truncate :: Integral b => Down a -> b

round :: Integral b => Down a -> b

ceiling :: Integral b => Down a -> b

floor :: Integral b => Down a -> b

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

HasResolution a => RealFrac (Fixed a)

Since: base-2.1

Defined in Data.Fixed

Methods

properFraction :: Integral b => Fixed a -> (b, Fixed a)

truncate :: Integral b => Fixed a -> b

round :: Integral b => Fixed a -> b

ceiling :: Integral b => Fixed a -> b

floor :: Integral b => Fixed a -> b

RealFrac a => RealFrac (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

properFraction :: Integral b0 => Const a b -> (b0, Const a b)

truncate :: Integral b0 => Const a b -> b0

round :: Integral b0 => Const a b -> b0

ceiling :: Integral b0 => Const a b -> b0

floor :: Integral b0 => Const a b -> b0

data Ratio a

Rational numbers, with numerator and denominator of some Integral type.

Note that Ratio's instances inherit the deficiencies from the type parameter's. For example, Ratio Natural's Num instance has similar problems to Natural's.

Instances

Integral a => Enum (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

succ :: Ratio a -> Ratio a

pred :: Ratio a -> Ratio a

toEnum :: Int -> Ratio a

fromEnum :: Ratio a -> Int

enumFrom :: Ratio a -> [Ratio a]

enumFromThen :: Ratio a -> Ratio a -> [Ratio a]

enumFromTo :: Ratio a -> Ratio a -> [Ratio a]

enumFromThenTo :: Ratio a -> Ratio a -> Ratio a -> [Ratio a]

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

(Integral a, Read a) => Read (Ratio a)

Since: base-2.1

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS (Ratio a)

readList :: ReadS [Ratio a]

readPrec :: ReadPrec (Ratio a)

readListPrec :: ReadPrec [Ratio a]

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

Integral a => Real (Ratio a)

Since: base-2.0.1

Defined in GHC.Real

Methods

toRational :: Ratio a -> Rational

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

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

Integral a => Default (Ratio a)

Defined in Data.Default.Class

Methods

def :: Ratio a

Eq a => Eq (Ratio a)

Since: base-2.1

Defined in GHC.Real

Methods

(==) :: Ratio a -> Ratio a -> Bool

(/=) :: Ratio a -> Ratio a -> Bool

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

even :: Integral a => a -> Bool

fromIntegral :: (Integral a, Num b) => a -> b

General coercion from Integral types.

WARNING: This function performs silent truncation if the result type is not at least as big as the argument's type.

realToFrac :: (Real a, Fractional b) => a -> b

General coercion to Fractional types.

WARNING: This function goes through the Rational type, which does not have values for NaN for example. This means it does not round-trip.

For Double it also behaves differently with or without -O0:

Prelude> realToFrac nan -- With -O0
-Infinity
Prelude> realToFrac nan
NaN

(^) :: (Num a, Integral b) => a -> b -> a infixr 8

raise a number to a non-negative integral power

numerator :: Ratio a -> a

Extract the numerator of the ratio in reduced form: the numerator and denominator have no common factor and the denominator is positive.

denominator :: Ratio a -> a

Extract the denominator of the ratio in reduced form: the numerator and denominator have no common factor and the denominator is positive.

odd :: Integral a => a -> Bool

(^^) :: (Fractional a, Integral b) => a -> b -> a infixr 8

raise a number to an integral power

gcd :: Integral a => a -> a -> a

gcd x y is the non-negative factor of both x and y of which every common factor of x and y is also a factor; for example gcd 4 2 = 2, gcd (-4) 6 = 2, gcd 0 4 = 4. gcd 0 0 = 0. (That is, the common divisor that is "greatest" in the divisibility preordering.)

Note: Since for signed fixed-width integer types, abs minBound < 0, the result may be negative if one of the arguments is minBound (and necessarily is if the other is 0 or minBound) for such types.

lcm :: Integral a => a -> a -> a

lcm x y is the smallest positive integer that both x and y divide.

class Show a

Conversion of values to readable Strings.

Derived instances of Show have the following properties, which are compatible with derived instances of Read:

• The result of show is a syntactically correct Haskell expression containing only constants, given the fixity declarations in force at the point where the type is declared. It contains only the constructor names defined in the data type, parentheses, and spaces. When labelled constructor fields are used, braces, commas, field names, and equal signs are also used.
• If the constructor is defined to be an infix operator, then showsPrec will produce infix applications of the constructor.
• the representation will be enclosed in parentheses if the precedence of the top-level constructor in x is less than d (associativity is ignored). Thus, if d is 0 then the result is never surrounded in parentheses; if d is 11 it is always surrounded in parentheses, unless it is an atomic expression.
• If the constructor is defined using record syntax, then show will produce the record-syntax form, with the fields given in the same order as the original declaration.

For example, given the declarations

infixr 5 :^:
data Tree a =  Leaf a  |  Tree a :^: Tree a

the derived instance of Show is equivalent to

instance (Show a) => Show (Tree a) where

       showsPrec d (Leaf m) = showParen (d > app_prec) $
            showString "Leaf " . showsPrec (app_prec+1) m
         where app_prec = 10

       showsPrec d (u :^: v) = showParen (d > up_prec) $
            showsPrec (up_prec+1) u .
            showString " :^: "      .
            showsPrec (up_prec+1) v
         where up_prec = 5

Note that right-associativity of :^: is ignored. For example,

• show (Leaf 1 :^: Leaf 2 :^: Leaf 3) produces the string "Leaf 1 :^: (Leaf 2 :^: Leaf 3)".

Minimal complete definition

showsPrec | show

Instances

Show SomeTypeRep

Since: base-4.10.0.0

Defined in Data.Typeable.Internal

Methods

showsPrec :: Int -> SomeTypeRep -> ShowS

show :: SomeTypeRep -> String

showList :: [SomeTypeRep] -> ShowS

Show Void

Since: base-4.8.0.0

Defined in Data.Void

Methods

showsPrec :: Int -> Void -> ShowS

show :: Void -> String

showList :: [Void] -> ShowS

Show ArithException

Since: base-4.0.0.0

Defined in GHC.Exception.Type

Methods

showsPrec :: Int -> ArithException -> ShowS

show :: ArithException -> String

showList :: [ArithException] -> ShowS

Show SomeException

Since: base-3.0

Defined in GHC.Exception.Type

Methods

showsPrec :: Int -> SomeException -> ShowS

show :: SomeException -> String

showList :: [SomeException] -> ShowS

Show Associativity

Since: base-4.6.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> Associativity -> ShowS

show :: Associativity -> String

showList :: [Associativity] -> ShowS

Show DecidedStrictness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> DecidedStrictness -> ShowS

show :: DecidedStrictness -> String

showList :: [DecidedStrictness] -> ShowS

Show Fixity

Since: base-4.6.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> Fixity -> ShowS

show :: Fixity -> String

showList :: [Fixity] -> ShowS

Show SourceStrictness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> SourceStrictness -> ShowS

show :: SourceStrictness -> String

showList :: [SourceStrictness] -> ShowS

Show SourceUnpackedness

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> SourceUnpackedness -> ShowS

show :: SourceUnpackedness -> String

showList :: [SourceUnpackedness] -> ShowS

Show MaskingState

Since: base-4.3.0.0

Defined in GHC.IO

Methods

showsPrec :: Int -> MaskingState -> ShowS

show :: MaskingState -> String

showList :: [MaskingState] -> 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 Int8

Since: base-2.1

Defined in GHC.Int

Methods

showsPrec :: Int -> Int8 -> ShowS

show :: Int8 -> String

showList :: [Int8] -> ShowS

Show FractionalExponentBase

Defined in GHC.Real

Methods

showsPrec :: Int -> FractionalExponentBase -> ShowS

show :: FractionalExponentBase -> String

showList :: [FractionalExponentBase] -> 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 SrcLoc

Since: base-4.9.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> SrcLoc -> ShowS

show :: SrcLoc -> String

showList :: [SrcLoc] -> ShowS

Show SomeChar

Defined in GHC.TypeLits

Methods

showsPrec :: Int -> SomeChar -> ShowS

show :: SomeChar -> String

showList :: [SomeChar] -> ShowS

Show SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

showsPrec :: Int -> SomeSymbol -> ShowS

show :: SomeSymbol -> String

showList :: [SomeSymbol] -> ShowS

Show SomeNat

Since: base-4.7.0.0

Defined in GHC.TypeNats

Methods

showsPrec :: Int -> SomeNat -> ShowS

show :: SomeNat -> String

showList :: [SomeNat] -> ShowS

Show Word16

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word16 -> ShowS

show :: Word16 -> String

showList :: [Word16] -> ShowS

Show Word32

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word32 -> ShowS

show :: Word32 -> String

showList :: [Word32] -> ShowS

Show Word64

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word64 -> ShowS

show :: Word64 -> String

showList :: [Word64] -> ShowS

Show Word8

Since: base-2.1

Defined in GHC.Word

Methods

showsPrec :: Int -> Word8 -> ShowS

show :: Word8 -> String

showList :: [Word8] -> ShowS

Show ByteString

Defined in Data.ByteString.Internal.Type

Methods

showsPrec :: Int -> ByteString -> ShowS

show :: ByteString -> String

showList :: [ByteString] -> ShowS

Show ByteString

Defined in Data.ByteString.Lazy.Internal

Methods

showsPrec :: Int -> ByteString -> ShowS

show :: ByteString -> String

showList :: [ByteString] -> ShowS

Show ShortByteString

Defined in Data.ByteString.Short.Internal

Methods

showsPrec :: Int -> ShortByteString -> ShowS

show :: ShortByteString -> String

showList :: [ShortByteString] -> ShowS

Show IntSet

Defined in Data.IntSet.Internal

Methods

showsPrec :: Int -> IntSet -> ShowS

show :: IntSet -> String

showList :: [IntSet] -> ShowS

Show KindRep

Defined in GHC.Show

Methods

showsPrec :: Int -> KindRep -> ShowS

show :: KindRep -> String

showList :: [KindRep] -> 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 Ordering

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Ordering -> ShowS

show :: Ordering -> String

showList :: [Ordering] -> 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 TyCon

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> TyCon -> ShowS

show :: TyCon -> String

showList :: [TyCon] -> ShowS

Show TypeLitSort

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> TypeLitSort -> ShowS

show :: TypeLitSort -> String

showList :: [TypeLitSort] -> ShowS

Show Decoding

Defined in Data.Text.Encoding

Methods

showsPrec :: Int -> Decoding -> ShowS

show :: Decoding -> String

showList :: [Decoding] -> ShowS

Show UnicodeException

Defined in Data.Text.Encoding.Error

Methods

showsPrec :: Int -> UnicodeException -> ShowS

show :: UnicodeException -> String

showList :: [UnicodeException] -> ShowS

Show Integer

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Integer -> ShowS

show :: Integer -> String

showList :: [Integer] -> ShowS

Show Natural

Since: base-4.8.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Natural -> ShowS

show :: Natural -> String

showList :: [Natural] -> ShowS

Show ()

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> () -> ShowS

show :: () -> String

showList :: [()] -> ShowS

Show Bool

Since: base-2.1

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 Levity

Since: base-4.15.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Levity -> ShowS

show :: Levity -> String

showList :: [Levity] -> ShowS

Show RuntimeRep

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> RuntimeRep -> ShowS

show :: RuntimeRep -> String

showList :: [RuntimeRep] -> ShowS

Show VecCount

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> VecCount -> ShowS

show :: VecCount -> String

showList :: [VecCount] -> ShowS

Show VecElem

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> VecElem -> ShowS

show :: VecElem -> String

showList :: [VecElem] -> ShowS

Show Word

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Word -> ShowS

show :: Word -> String

showList :: [Word] -> ShowS

Show a => Show (ZipList a)

Since: base-4.7.0.0

Defined in Control.Applicative

Methods

showsPrec :: Int -> ZipList a -> ShowS

show :: ZipList a -> String

showList :: [ZipList a] -> ShowS

Show a => Show (And a)

Since: base-4.16

Defined in Data.Bits

Methods

showsPrec :: Int -> And a -> ShowS

show :: And a -> String

showList :: [And a] -> ShowS

Show a => Show (Iff a)

Since: base-4.16

Defined in Data.Bits

Methods

showsPrec :: Int -> Iff a -> ShowS

show :: Iff a -> String

showList :: [Iff a] -> ShowS

Show a => Show (Ior a)

Since: base-4.16

Defined in Data.Bits

Methods

showsPrec :: Int -> Ior a -> ShowS

show :: Ior a -> String

showList :: [Ior a] -> ShowS

Show a => Show (Xor a)

Since: base-4.16

Defined in Data.Bits

Methods

showsPrec :: Int -> Xor a -> ShowS

show :: Xor a -> String

showList :: [Xor a] -> ShowS

Show a => Show (Complex a)

Since: base-2.1

Defined in Data.Complex

Methods

showsPrec :: Int -> Complex a -> ShowS

show :: Complex a -> String

showList :: [Complex a] -> ShowS

Show a => Show (Identity a)

This instance would be equivalent to the derived instances of the Identity newtype if the runIdentity field were removed

Since: base-4.8.0.0

Defined in Data.Functor.Identity

Methods

showsPrec :: Int -> Identity a -> ShowS

show :: Identity a -> String

showList :: [Identity a] -> ShowS

Show a => Show (First a)

Since: base-2.1

Defined in Data.Monoid

Methods

showsPrec :: Int -> First a -> ShowS

show :: First a -> String

showList :: [First a] -> ShowS

Show a => Show (Last a)

Since: base-2.1

Defined in Data.Monoid

Methods

showsPrec :: Int -> Last a -> ShowS

show :: Last a -> String

showList :: [Last a] -> ShowS

Show a => Show (Down a)

This instance would be equivalent to the derived instances of the Down newtype if the getDown field were removed

Since: base-4.7.0.0

Defined in Data.Ord

Methods

showsPrec :: Int -> Down a -> ShowS

show :: Down a -> String

showList :: [Down a] -> ShowS

Show a => Show (First a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

showsPrec :: Int -> First a -> ShowS

show :: First a -> String

showList :: [First a] -> ShowS

Show a => Show (Last a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

showsPrec :: Int -> Last a -> ShowS

show :: Last a -> String

showList :: [Last a] -> ShowS

Show a => Show (Max a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

showsPrec :: Int -> Max a -> ShowS

show :: Max a -> String

showList :: [Max a] -> ShowS

Show a => Show (Min a)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

showsPrec :: Int -> Min a -> ShowS

show :: Min a -> String

showList :: [Min a] -> ShowS

Show m => Show (WrappedMonoid m)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

showsPrec :: Int -> WrappedMonoid m -> ShowS

show :: WrappedMonoid m -> String

showList :: [WrappedMonoid m] -> ShowS

Show p => Show (Par1 p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> Par1 p -> ShowS

show :: Par1 p -> String

showList :: [Par1 p] -> 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 a => Show (IntMap a)

Defined in Data.IntMap.Internal

Methods

showsPrec :: Int -> IntMap a -> ShowS

show :: IntMap a -> String

showList :: [IntMap a] -> ShowS

Show a => Show (Seq a)

Defined in Data.Sequence.Internal

Methods

showsPrec :: Int -> Seq a -> ShowS

show :: Seq a -> String

showList :: [Seq a] -> ShowS

Show a => Show (ViewL a)

Defined in Data.Sequence.Internal

Methods

showsPrec :: Int -> ViewL a -> ShowS

show :: ViewL a -> String

showList :: [ViewL a] -> ShowS

Show a => Show (ViewR a)

Defined in Data.Sequence.Internal

Methods

showsPrec :: Int -> ViewR a -> ShowS

show :: ViewR a -> String

showList :: [ViewR a] -> ShowS

Show a => Show (Intersection a)

Defined in Data.Set.Internal

Methods

showsPrec :: Int -> Intersection a -> ShowS

show :: Intersection a -> String

showList :: [Intersection 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 (DList a)

Defined in Data.DList.Internal

Methods

showsPrec :: Int -> DList a -> ShowS

show :: DList a -> String

showList :: [DList a] -> ShowS

Show a => Show (NonEmpty a)

Since: base-4.11.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> NonEmpty a -> ShowS

show :: NonEmpty a -> String

showList :: [NonEmpty a] -> ShowS

Show a => Show (Maybe a)

Since: base-2.1

Defined in GHC.Show

Methods

showsPrec :: Int -> Maybe a -> ShowS

show :: Maybe a -> String

showList :: [Maybe a] -> ShowS

Show a => Show (a)

Since: base-4.15

Defined in GHC.Show

Methods

showsPrec :: Int -> (a) -> ShowS

show :: (a) -> String

showList :: [(a)] -> 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 b) => Show (Either a b)

Since: base-3.0

Defined in Data.Either

Methods

showsPrec :: Int -> Either a b -> ShowS

show :: Either a b -> String

showList :: [Either a b] -> ShowS

HasResolution a => Show (Fixed a)

Since: base-2.1

Defined in Data.Fixed

Methods

showsPrec :: Int -> Fixed a -> ShowS

show :: Fixed a -> String

showList :: [Fixed a] -> 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 a, Show b) => Show (Arg a b)

Since: base-4.9.0.0

Defined in Data.Semigroup

Methods

showsPrec :: Int -> Arg a b -> ShowS

show :: Arg a b -> String

showList :: [Arg a b] -> ShowS

Show (TypeRep a)

Defined in Data.Typeable.Internal

Methods

showsPrec :: Int -> TypeRep a -> ShowS

show :: TypeRep a -> String

showList :: [TypeRep a] -> 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 (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 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 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

Show a => Show (Const a b)

This instance would be equivalent to the derived instances of the Const newtype if the getConst field were removed

Since: base-4.8.0.0

Defined in Data.Functor.Const

Methods

showsPrec :: Int -> Const a b -> ShowS

show :: Const a b -> String

showList :: [Const a b] -> ShowS

Show (f a) => Show (Ap f a)

Since: base-4.12.0.0

Defined in Data.Monoid

Methods

showsPrec :: Int -> Ap f a -> ShowS

show :: Ap f a -> String

showList :: [Ap f a] -> ShowS

Show (a :~: b)

Since: base-4.7.0.0

Defined in Data.Type.Equality

Methods

showsPrec :: Int -> (a :~: b) -> ShowS

show :: (a :~: b) -> String

showList :: [a :~: b] -> ShowS

Show (OrderingI a b)

Defined in Data.Type.Ord

Methods

showsPrec :: Int -> OrderingI a b -> ShowS

show :: OrderingI a b -> String

showList :: [OrderingI a b] -> ShowS

Show (f p) => Show (Rec1 f p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> Rec1 f p -> ShowS

show :: Rec1 f p -> String

showList :: [Rec1 f p] -> ShowS

Show (URec Char p)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> URec Char p -> ShowS

show :: URec Char p -> String

showList :: [URec Char p] -> ShowS

Show (URec Double p)

Since: base-4.9.0.0

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)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> URec Int p -> ShowS

show :: URec Int p -> String

showList :: [URec Int p] -> ShowS

Show (URec Word p)

Since: base-4.9.0.0

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

(Show1 f, Show1 g, Show a) => Show (Product f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Product

Methods

showsPrec :: Int -> Product f g a -> ShowS

show :: Product f g a -> String

showList :: [Product f g a] -> ShowS

(Show1 f, Show1 g, Show a) => Show (Sum f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Sum

Methods

showsPrec :: Int -> Sum f g a -> ShowS

show :: Sum f g a -> String

showList :: [Sum f g a] -> ShowS

Show (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 (g p)) => Show ((f :*: g) p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> (f :*: g) p -> ShowS

show :: (f :*: g) p -> String

showList :: [(f :*: g) p] -> ShowS

(Show (f p), Show (g p)) => Show ((f :+: g) p)

Since: base-4.7.0.0

Defined in GHC.Generics

Methods

showsPrec :: Int -> (f :+: g) p -> ShowS

show :: (f :+: g) p -> String

showList :: [(f :+: g) p] -> ShowS

Show c => Show (K1 i c p)

Since: base-4.7.0.0

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 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

(Show1 f, Show1 g, Show a) => Show (Compose f g a)

Since: base-4.9.0.0

Defined in Data.Functor.Compose

Methods

showsPrec :: Int -> Compose f g a -> ShowS

show :: Compose f g a -> String

showList :: [Compose f g a] -> ShowS

Show (f (g p)) => Show ((f :.: g) p)

Since: base-4.7.0.0

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 (M1 i c f p)

Since: base-4.7.0.0

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 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

type HasCallStack = ?callStack :: CallStack

Request a CallStack.

NOTE: The implicit parameter ?callStack :: CallStack is an implementation detail and should not be considered part of the CallStack API, we may decide to change the implementation in the future.

Since: base-4.9.0.0

withFrozenCallStack :: HasCallStack => (HasCallStack => a) -> a

Perform some computation without adding new entries to the CallStack.

Since: base-4.9.0.0

data Symbol

(Kind) This is the kind of type-level symbols. Declared here because class IP needs it

Instances

SingKind Symbol

Since: base-4.9.0.0

Defined in GHC.Generics

Associated Types

type DemoteRep Symbol

Methods

fromSing :: forall (a :: Symbol). Sing a -> DemoteRep Symbol

KnownSymbol a => SingI (a :: Symbol)

Since: base-4.9.0.0

Defined in GHC.Generics

Methods

sing :: Sing a

type DemoteRep Symbol

Defined in GHC.Generics

type DemoteRep Symbol = String

data Sing (s :: Symbol)

Defined in GHC.Generics

data Sing (s :: Symbol) where

• SSym :: forall (s :: Symbol). KnownSymbol s => Sing s

type Compare (a :: Symbol) (b :: Symbol)

Defined in Data.Type.Ord

type Compare (a :: Symbol) (b :: Symbol) = CmpSymbol a b

data Natural

Natural number

Invariant: numbers <= 0xffffffffffffffff use the NS constructor

Instances

Bits Natural

Since: base-4.8.0

Defined in GHC.Bits

Methods

(.&.) :: Natural -> Natural -> Natural

(.|.) :: Natural -> Natural -> Natural

xor :: Natural -> Natural -> Natural

complement :: Natural -> Natural

shift :: Natural -> Int -> Natural

rotate :: Natural -> Int -> Natural

zeroBits :: Natural

bit :: Int -> Natural

setBit :: Natural -> Int -> Natural

clearBit :: Natural -> Int -> Natural

complementBit :: Natural -> Int -> Natural

testBit :: Natural -> Int -> Bool

bitSizeMaybe :: Natural -> Maybe Int

bitSize :: Natural -> Int

isSigned :: Natural -> Bool

shiftL :: Natural -> Int -> Natural

unsafeShiftL :: Natural -> Int -> Natural

shiftR :: Natural -> Int -> Natural

unsafeShiftR :: Natural -> Int -> Natural

rotateL :: Natural -> Int -> Natural

rotateR :: Natural -> Int -> Natural

popCount :: Natural -> Int

Enum Natural

Since: base-4.8.0.0

Defined in GHC.Enum

Methods

succ :: Natural -> Natural

pred :: Natural -> Natural

toEnum :: Int -> Natural

fromEnum :: Natural -> Int

enumFrom :: Natural -> [Natural]

enumFromThen :: Natural -> Natural -> [Natural]

enumFromTo :: Natural -> Natural -> [Natural]

enumFromThenTo :: Natural -> Natural -> Natural -> [Natural]

Num Natural

Note that Natural's Num instance isn't a ring: no element but 0 has an additive inverse. It is a semiring though.

Since: base-4.8.0.0

Defined in GHC.Num

Methods

(+) :: Natural -> Natural -> Natural

(-) :: Natural -> Natural -> Natural

(*) :: Natural -> Natural -> Natural

negate :: Natural -> Natural

abs :: Natural -> Natural

signum :: Natural -> Natural

fromInteger :: Integer -> Natural

Read Natural

Since: base-4.8.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Natural

readList :: ReadS [Natural]

readPrec :: ReadPrec Natural

readListPrec :: ReadPrec [Natural]

Integral Natural

Since: base-4.8.0.0

Defined in GHC.Real

Methods

quot :: Natural -> Natural -> Natural

rem :: Natural -> Natural -> Natural

div :: Natural -> Natural -> Natural

mod :: Natural -> Natural -> Natural

quotRem :: Natural -> Natural -> (Natural, Natural)

divMod :: Natural -> Natural -> (Natural, Natural)

toInteger :: Natural -> Integer

Real Natural

Since: base-4.8.0.0

Defined in GHC.Real

Methods

toRational :: Natural -> Rational

Show Natural

Since: base-4.8.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Natural -> ShowS

show :: Natural -> String

showList :: [Natural] -> ShowS

Eq Natural

Defined in GHC.Num.Natural

Methods

(==) :: Natural -> Natural -> Bool

(/=) :: Natural -> Natural -> Bool

Ord Natural

Defined in GHC.Num.Natural

Methods

compare :: Natural -> Natural -> Ordering

(<) :: Natural -> Natural -> Bool

(<=) :: Natural -> Natural -> Bool

(>) :: Natural -> Natural -> Bool

(>=) :: Natural -> Natural -> Bool

max :: Natural -> Natural -> Natural

min :: Natural -> Natural -> Natural

KnownNat n => HasResolution (n :: Nat)

For example, Fixed 1000 will give you a Fixed with a resolution of 1000.

Defined in Data.Fixed

Methods

resolution :: p n -> Integer

type Compare (a :: Natural) (b :: Natural)

Defined in Data.Type.Ord

type Compare (a :: Natural) (b :: Natural) = CmpNat a b

type family (a :: Natural) - (b :: Natural) :: Natural where ... infixl 6

Subtraction of type-level naturals.

Since: base-4.7.0.0

class KnownNat (n :: Nat)

This class gives the integer associated with a type-level natural. There are instances of the class for every concrete literal: 0, 1, 2, etc.

Since: base-4.7.0.0

Minimal complete definition

natSing

class KnownSymbol (n :: Symbol)

This class gives the string associated with a type-level symbol. There are instances of the class for every concrete literal: "hello", etc.

Since: base-4.7.0.0

Minimal complete definition

symbolSing

class KnownChar (n :: Char)

Since: base-4.16.0.0

Minimal complete definition

charSing

type family TypeError (a :: ErrorMessage) :: b where ...

The type-level equivalent of error.

The polymorphic kind of this type allows it to be used in several settings. For instance, it can be used as a constraint, e.g. to provide a better error message for a non-existent instance,

-- in a context
instance TypeError (Text "Cannot Show functions." :$$:
                    Text "Perhaps there is a missing argument?")
      => Show (a -> b) where
    showsPrec = error "unreachable"

It can also be placed on the right-hand side of a type-level function to provide an error for an invalid case,

type family ByteSize x where
   ByteSize Word16   = 2
   ByteSize Word8    = 1
   ByteSize a        = TypeError (Text "The type " :<>: ShowType a :<>:
                                  Text " is not exportable.")

Since: base-4.9.0.0

type family AppendSymbol (a :: Symbol) (b :: Symbol) :: Symbol where ...

Concatenation of type-level symbols.

Since: base-4.10.0.0

type family (a :: Natural) + (b :: Natural) :: Natural where ... infixl 6

Addition of type-level naturals.

Since: base-4.7.0.0

type family (a :: Natural) * (b :: Natural) :: Natural where ... infixl 7

Multiplication of type-level naturals.

Since: base-4.7.0.0

type family (a :: Natural) ^ (b :: Natural) :: Natural where ... infixr 8

Exponentiation of type-level naturals.

Since: base-4.7.0.0

type family CmpSymbol (a :: Symbol) (b :: Symbol) :: Ordering where ...

Comparison of type-level symbols, as a function.

Since: base-4.7.0.0

type family CmpNat (a :: Natural) (b :: Natural) :: Ordering where ...

Comparison of type-level naturals, as a function.

Since: base-4.7.0.0

type family CmpChar (a :: Char) (b :: Char) :: Ordering where ...

Comparison of type-level characters.

Since: base-4.16.0.0

type family Div (a :: Natural) (b :: Natural) :: Natural where ... infixl 7

Division (round down) of natural numbers. Div x 0 is undefined (i.e., it cannot be reduced).

Since: base-4.11.0.0

type family Mod (a :: Natural) (b :: Natural) :: Natural where ... infixl 7

Modulus of natural numbers. Mod x 0 is undefined (i.e., it cannot be reduced).

Since: base-4.11.0.0

type family Log2 (a :: Natural) :: Natural where ...

Log base 2 (round down) of natural numbers. Log 0 is undefined (i.e., it cannot be reduced).

Since: base-4.11.0.0

type family ConsSymbol (a :: Char) (b :: Symbol) :: Symbol where ...

Extending a type-level symbol with a type-level character

Since: base-4.16.0.0

type family UnconsSymbol (a :: Symbol) :: Maybe (Char, Symbol) where ...

This type family yields type-level Just storing the first character of a symbol and its tail if it is defined and Nothing otherwise.

Since: base-4.16.0.0

type family CharToNat (a :: Char) :: Natural where ...

Convert a character to its Unicode code point (cf. ord)

Since: base-4.16.0.0

type family NatToChar (a :: Natural) :: Char where ...

Convert a Unicode code point to a character (cf. chr)

Since: base-4.16.0.0

type (<=) (x :: t) (y :: t) = Assert (x <=? y) (LeErrMsg x y :: Constraint) infix 4

Comparison (<=) of comparable types, as a constraint.

Since: base-4.16.0.0

type (<=?) (m :: k) (n :: k) = OrdCond (Compare m n) 'True 'True 'False infix 4

Comparison (<=) of comparable types, as a function.

Since: base-4.16.0.0

data OrderingI (a :: k) (b :: k) where

Ordering data type for type literals that provides proof of their ordering.

Since: base-4.16.0.0

Constructors

LTI :: forall {k} (a :: k) (b :: k). Compare a b ~ 'LT => OrderingI a b

EQI :: forall {k} (a :: k). Compare a a ~ 'EQ => OrderingI a a

GTI :: forall {k} (a :: k) (b :: k). Compare a b ~ 'GT => OrderingI a b

Instances

Show (OrderingI a b)

Defined in Data.Type.Ord

Methods

showsPrec :: Int -> OrderingI a b -> ShowS

show :: OrderingI a b -> String

showList :: [OrderingI a b] -> ShowS

Eq (OrderingI a b)

Defined in Data.Type.Ord

Methods

(==) :: OrderingI a b -> OrderingI a b -> Bool

(/=) :: OrderingI a b -> OrderingI a b -> Bool

data SomeNat

This type represents unknown type-level natural numbers.

Since: base-4.10.0.0

Constructors

KnownNat n => SomeNat (Proxy n)

Instances

Read SomeNat

Since: base-4.7.0.0

Defined in GHC.TypeNats

Methods

readsPrec :: Int -> ReadS SomeNat

readList :: ReadS [SomeNat]

readPrec :: ReadPrec SomeNat

readListPrec :: ReadPrec [SomeNat]

Show SomeNat

Since: base-4.7.0.0

Defined in GHC.TypeNats

Methods

showsPrec :: Int -> SomeNat -> ShowS

show :: SomeNat -> String

showList :: [SomeNat] -> ShowS

Eq SomeNat

Since: base-4.7.0.0

Defined in GHC.TypeNats

Methods

(==) :: SomeNat -> SomeNat -> Bool

(/=) :: SomeNat -> SomeNat -> Bool

Ord SomeNat

Since: base-4.7.0.0

Defined in GHC.TypeNats

Methods

compare :: SomeNat -> SomeNat -> Ordering

(<) :: SomeNat -> SomeNat -> Bool

(<=) :: SomeNat -> SomeNat -> Bool

(>) :: SomeNat -> SomeNat -> Bool

(>=) :: SomeNat -> SomeNat -> Bool

max :: SomeNat -> SomeNat -> SomeNat

min :: SomeNat -> SomeNat -> SomeNat

type Nat = Natural

A type synonym for Natural.

Prevously, this was an opaque data type, but it was changed to a type synonym.

Since: base-4.16.0.0

data SomeChar

Constructors

KnownChar n => SomeChar (Proxy n)

Instances

Read SomeChar

Defined in GHC.TypeLits

Methods

readsPrec :: Int -> ReadS SomeChar

readList :: ReadS [SomeChar]

readPrec :: ReadPrec SomeChar

readListPrec :: ReadPrec [SomeChar]

Show SomeChar

Defined in GHC.TypeLits

Methods

showsPrec :: Int -> SomeChar -> ShowS

show :: SomeChar -> String

showList :: [SomeChar] -> ShowS

Eq SomeChar

Defined in GHC.TypeLits

Methods

(==) :: SomeChar -> SomeChar -> Bool

(/=) :: SomeChar -> SomeChar -> Bool

Ord SomeChar

Defined in GHC.TypeLits

Methods

compare :: SomeChar -> SomeChar -> Ordering

(<) :: SomeChar -> SomeChar -> Bool

(<=) :: SomeChar -> SomeChar -> Bool

(>) :: SomeChar -> SomeChar -> Bool

(>=) :: SomeChar -> SomeChar -> Bool

max :: SomeChar -> SomeChar -> SomeChar

min :: SomeChar -> SomeChar -> SomeChar

data SomeSymbol

This type represents unknown type-level symbols.

Constructors

KnownSymbol n => SomeSymbol (Proxy n)

Since: base-4.7.0.0

Instances

Read SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

readsPrec :: Int -> ReadS SomeSymbol

readList :: ReadS [SomeSymbol]

readPrec :: ReadPrec SomeSymbol

readListPrec :: ReadPrec [SomeSymbol]

Show SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

showsPrec :: Int -> SomeSymbol -> ShowS

show :: SomeSymbol -> String

showList :: [SomeSymbol] -> ShowS

Eq SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

(==) :: SomeSymbol -> SomeSymbol -> Bool

(/=) :: SomeSymbol -> SomeSymbol -> Bool

Ord SomeSymbol

Since: base-4.7.0.0

Defined in GHC.TypeLits

Methods

compare :: SomeSymbol -> SomeSymbol -> Ordering

(<) :: SomeSymbol -> SomeSymbol -> Bool

(<=) :: SomeSymbol -> SomeSymbol -> Bool

(>) :: SomeSymbol -> SomeSymbol -> Bool

(>=) :: SomeSymbol -> SomeSymbol -> Bool

max :: SomeSymbol -> SomeSymbol -> SomeSymbol

min :: SomeSymbol -> SomeSymbol -> SomeSymbol

pattern ShowType :: t -> ErrorMessage

Pretty print the type. ShowType :: k -> ErrorMessage

pattern (:<>:) :: ErrorMessage -> ErrorMessage -> ErrorMessage infixl 6

Put two pieces of error message next to each other.

pattern (:$$:) :: ErrorMessage -> ErrorMessage -> ErrorMessage infixl 5

Stack two pieces of error message on top of each other.

natVal :: forall (n :: Nat) proxy. KnownNat n => proxy n -> Integer

Since: base-4.7.0.0

natVal' :: forall (n :: Nat). KnownNat n => Proxy# n -> Integer

Since: base-4.8.0.0

someNatVal :: Integer -> Maybe SomeNat

Convert an integer into an unknown type-level natural.

Since: base-4.7.0.0

sameNat :: forall (a :: Nat) (b :: Nat) proxy1 proxy2. (KnownNat a, KnownNat b) => proxy1 a -> proxy2 b -> Maybe (a :~: b)

We either get evidence that this function was instantiated with the same type-level numbers, or Nothing.

Since: base-4.7.0.0

cmpNat :: forall (a :: Nat) (b :: Nat) proxy1 proxy2. (KnownNat a, KnownNat b) => proxy1 a -> proxy2 b -> OrderingI a b

Like sameNat, but if the numbers aren't equal, this additionally provides proof of LT or GT.

Since: base-4.16.0.0

symbolVal :: forall (n :: Symbol) proxy. KnownSymbol n => proxy n -> String

Since: base-4.7.0.0

symbolVal' :: forall (n :: Symbol). KnownSymbol n => Proxy# n -> String

Since: base-4.8.0.0

charVal :: forall (n :: Char) proxy. KnownChar n => proxy n -> Char

charVal' :: forall (n :: Char). KnownChar n => Proxy# n -> Char

someSymbolVal :: String -> SomeSymbol

Convert a string into an unknown type-level symbol.

Since: base-4.7.0.0

someCharVal :: Char -> SomeChar

Convert a character into an unknown type-level char.

Since: base-4.16.0.0

sameSymbol :: forall (a :: Symbol) (b :: Symbol) proxy1 proxy2. (KnownSymbol a, KnownSymbol b) => proxy1 a -> proxy2 b -> Maybe (a :~: b)

We either get evidence that this function was instantiated with the same type-level symbols, or Nothing.

Since: base-4.7.0.0

sameChar :: forall (a :: Char) (b :: Char) proxy1 proxy2. (KnownChar a, KnownChar b) => proxy1 a -> proxy2 b -> Maybe (a :~: b)

We either get evidence that this function was instantiated with the same type-level characters, or Nothing.

Since: base-4.16.0.0

cmpSymbol :: forall (a :: Symbol) (b :: Symbol) proxy1 proxy2. (KnownSymbol a, KnownSymbol b) => proxy1 a -> proxy2 b -> OrderingI a b

Like sameSymbol, but if the symbols aren't equal, this additionally provides proof of LT or GT.

Since: base-4.16.0.0

cmpChar :: forall (a :: Char) (b :: Char) proxy1 proxy2. (KnownChar a, KnownChar b) => proxy1 a -> proxy2 b -> OrderingI a b

Like sameChar, but if the Chars aren't equal, this additionally provides proof of LT or GT.

Since: base-4.16.0.0

module Incipit.Fixed

module Incipit.Foldable

module Incipit.Fractional

quot :: Integral a => a -> a -> Maybe a

integer division truncated toward zero

rem :: Integral a => a -> a -> Maybe a

integer remainder, satisfying

(x `quot` y)*y + (x `rem` y) == x

div :: Integral a => a -> a -> Maybe a

integer division truncated toward negative infinity

mod :: Integral a => a -> a -> Maybe a

integer modulus, satisfying

(x `div` y)*y + (x `mod` y) == x

quotRem :: Integral a => a -> a -> Maybe (a, a)

simultaneous quot and rem

divMod :: Integral a => a -> a -> Maybe (a, a)

simultaneous div and mod

data Natural

Natural number

Invariant: numbers <= 0xffffffffffffffff use the NS constructor

Instances

Bits Natural

Since: base-4.8.0

Defined in GHC.Bits

Methods

(.&.) :: Natural -> Natural -> Natural

(.|.) :: Natural -> Natural -> Natural

xor :: Natural -> Natural -> Natural

complement :: Natural -> Natural

shift :: Natural -> Int -> Natural

rotate :: Natural -> Int -> Natural

zeroBits :: Natural

bit :: Int -> Natural

setBit :: Natural -> Int -> Natural

clearBit :: Natural -> Int -> Natural

complementBit :: Natural -> Int -> Natural

testBit :: Natural -> Int -> Bool

bitSizeMaybe :: Natural -> Maybe Int

bitSize :: Natural -> Int

isSigned :: Natural -> Bool

shiftL :: Natural -> Int -> Natural

unsafeShiftL :: Natural -> Int -> Natural

shiftR :: Natural -> Int -> Natural

unsafeShiftR :: Natural -> Int -> Natural

rotateL :: Natural -> Int -> Natural

rotateR :: Natural -> Int -> Natural

popCount :: Natural -> Int

Enum Natural

Since: base-4.8.0.0

Defined in GHC.Enum

Methods

succ :: Natural -> Natural

pred :: Natural -> Natural

toEnum :: Int -> Natural

fromEnum :: Natural -> Int

enumFrom :: Natural -> [Natural]

enumFromThen :: Natural -> Natural -> [Natural]

enumFromTo :: Natural -> Natural -> [Natural]

enumFromThenTo :: Natural -> Natural -> Natural -> [Natural]

Num Natural

Note that Natural's Num instance isn't a ring: no element but 0 has an additive inverse. It is a semiring though.

Since: base-4.8.0.0

Defined in GHC.Num

Methods

(+) :: Natural -> Natural -> Natural

(-) :: Natural -> Natural -> Natural

(*) :: Natural -> Natural -> Natural

negate :: Natural -> Natural

abs :: Natural -> Natural

signum :: Natural -> Natural

fromInteger :: Integer -> Natural

Read Natural

Since: base-4.8.0.0

Defined in GHC.Read

Methods

readsPrec :: Int -> ReadS Natural

readList :: ReadS [Natural]

readPrec :: ReadPrec Natural

readListPrec :: ReadPrec [Natural]

Integral Natural

Since: base-4.8.0.0

Defined in GHC.Real

Methods

quot :: Natural -> Natural -> Natural

rem :: Natural -> Natural -> Natural

div :: Natural -> Natural -> Natural

mod :: Natural -> Natural -> Natural

quotRem :: Natural -> Natural -> (Natural, Natural)

divMod :: Natural -> Natural -> (Natural, Natural)

toInteger :: Natural -> Integer

Real Natural

Since: base-4.8.0.0

Defined in GHC.Real

Methods

toRational :: Natural -> Rational

Show Natural

Since: base-4.8.0.0

Defined in GHC.Show

Methods

showsPrec :: Int -> Natural -> ShowS

show :: Natural -> String

showList :: [Natural] -> ShowS

Eq Natural

Defined in GHC.Num.Natural

Methods

(==) :: Natural -> Natural -> Bool

(/=) :: Natural -> Natural -> Bool

Ord Natural

Defined in GHC.Num.Natural

Methods

compare :: Natural -> Natural -> Ordering

(<) :: Natural -> Natural -> Bool

(<=) :: Natural -> Natural -> Bool

(>) :: Natural -> Natural -> Bool

(>=) :: Natural -> Natural -> Bool

max :: Natural -> Natural -> Natural

min :: Natural -> Natural -> Natural

KnownNat n => HasResolution (n :: Nat)

For example, Fixed 1000 will give you a Fixed with a resolution of 1000.

Defined in Data.Fixed

Methods

resolution :: p n -> Integer

type Compare (a :: Natural) (b :: Natural)

Defined in Data.Type.Ord

type Compare (a :: Natural) (b :: Natural) = CmpNat a b

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

MonadFail IO

Since: base-4.9.0.0

Defined in Control.Monad.Fail

Methods

fail :: String -> 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]

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

Functor IO

Since: base-2.1

Defined in GHC.Base

Methods

fmap :: (a -> b) -> IO a -> IO b

(<$) :: a -> IO b -> IO 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

MonadPlus IO

Since: base-4.9.0.0

Defined in GHC.Base

Methods

mzero :: IO a

mplus :: IO a -> 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

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

Default a => Default (IO a)

Defined in Data.Default.Class

Methods

def :: 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.

putStrLn :: String -> IO ()

The same as putStr, but adds a newline character.

print :: Show a => a -> IO ()

The print function outputs a value of any printable type to the standard output device. Printable types are those that are instances of class Show; print converts values to strings for output using the show operation and adds a newline.

For example, a program to print the first 20 integers and their powers of 2 could be written as:

main = print ([(n, 2^n) | n <- [0..19]])

putStr :: String -> IO ()

Write a string to the standard output device (same as hPutStr stdout).

showsPrec

Arguments

:: Show a

=> Int

the operator precedence of the enclosing context (a number from 0 to 11). Function application has precedence 10.

-> a

the value to be converted to a String

-> ShowS

Convert a value to a readable String.

showsPrec should satisfy the law

showsPrec d x r ++ s  ==  showsPrec d x (r ++ s)

Derived instances of Read and Show satisfy the following:

• (x,"") is an element of (readsPrec d (showsPrec d x "")).

That is, readsPrec parses the string produced by showsPrec, and delivers the value that showsPrec started with.

showString :: String -> ShowS

utility function converting a String to a show function that simply prepends the string unchanged.

showParen :: Bool -> ShowS -> ShowS

utility function that surrounds the inner show function with parentheses when the Bool parameter is True.