Copyright	(c) The University of Glasgow 2001
License	BSD-style (see the file libraries/base/LICENSE)
Maintainer	libraries@haskell.org
Stability	provisional
Portability	portable
Safe Haskell	Trustworthy
Language	Haskell2010

Control.Monad.Instances

Description

Deprecated: This module now contains no instances and will be removed in the future

This module is DEPRECATED and will be removed in the future!

Functor and Monad instances for (->) r and Functor instances for (,) a and Either a.

Synopsis

class Functor (f :: Type -> Type) where
- fmap :: (a -> b) -> f a -> f b
- (<$) :: a -> f b -> f a
class Applicative m => Monad (m :: Type -> Type) where
- (>>=) :: m a -> (a -> m b) -> m b
- (>>) :: m a -> m b -> m b
- return :: a -> m a

Documentation

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

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 these articles by School of Haskell or David Luposchainsky for an explanation.

Minimal complete definition

fmap

Methods

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

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

Expand

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 Source #

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.

Examples

Expand

Perform a computation with Maybe and replace the result with a constant value if it is Just:

>>> 'a' <$ Just 2
Just 'a'
>>> 'a' <$ Nothing
Nothing

Instances

Instances details

Functor Complex Source #	Since: base-4.9.0.0
Instance details Defined in Data.Complex Methods fmap :: (a -> b) -> Complex a -> Complex b Source # (<$) :: a -> Complex b -> Complex a Source #
Functor First Source #	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fmap :: (a -> b) -> First a -> First b Source # (<$) :: a -> First b -> First a Source #
Functor Last Source #	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fmap :: (a -> b) -> Last a -> Last b Source # (<$) :: a -> Last b -> Last a Source #
Functor Max Source #	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fmap :: (a -> b) -> Max a -> Max b Source # (<$) :: a -> Max b -> Max a Source #
Functor Min Source #	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fmap :: (a -> b) -> Min a -> Min b Source # (<$) :: a -> Min b -> Min a Source #
Functor ArgDescr Source #	Since: base-4.7.0.0
Instance details Defined in System.Console.GetOpt Methods fmap :: (a -> b) -> ArgDescr a -> ArgDescr b Source # (<$) :: a -> ArgDescr b -> ArgDescr a Source #
Functor ArgOrder Source #	Since: base-4.7.0.0
Instance details Defined in System.Console.GetOpt Methods fmap :: (a -> b) -> ArgOrder a -> ArgOrder b Source # (<$) :: a -> ArgOrder b -> ArgOrder a Source #
Functor OptDescr Source #	Since: base-4.7.0.0
Instance details Defined in System.Console.GetOpt Methods fmap :: (a -> b) -> OptDescr a -> OptDescr b Source # (<$) :: a -> OptDescr b -> OptDescr a Source #
Functor NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Base Methods fmap :: (a -> b) -> NonEmpty a -> NonEmpty b Source # (<$) :: a -> NonEmpty b -> NonEmpty a Source #
Functor STM	Since: base-4.3.0.0
Instance details Defined in GHC.Internal.Conc.Sync Methods fmap :: (a -> b) -> STM a -> STM b Source # (<$) :: a -> STM b -> STM a Source #
Functor Handler	Since: base-4.6.0.0
Instance details Defined in GHC.Internal.Control.Exception Methods fmap :: (a -> b) -> Handler a -> Handler b Source # (<$) :: a -> Handler b -> Handler a Source #
Functor Identity	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Functor.Identity Methods fmap :: (a -> b) -> Identity a -> Identity b Source # (<$) :: a -> Identity b -> Identity a Source #
Functor First	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Monoid Methods fmap :: (a -> b) -> First a -> First b Source # (<$) :: a -> First b -> First a Source #
Functor Last	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Monoid Methods fmap :: (a -> b) -> Last a -> Last b Source # (<$) :: a -> Last b -> Last a Source #
Functor Down	Since: base-4.11.0.0
Instance details Defined in GHC.Internal.Data.Ord Methods fmap :: (a -> b) -> Down a -> Down b Source # (<$) :: a -> Down b -> Down a Source #
Functor Dual	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Semigroup.Internal Methods fmap :: (a -> b) -> Dual a -> Dual b Source # (<$) :: a -> Dual b -> Dual a Source #
Functor Product	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Semigroup.Internal Methods fmap :: (a -> b) -> Product a -> Product b Source # (<$) :: a -> Product b -> Product a Source #
Functor Sum	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Semigroup.Internal Methods fmap :: (a -> b) -> Sum a -> Sum b Source # (<$) :: a -> Sum b -> Sum a Source #
Functor ZipList	Since: base-2.1
Instance details Defined in GHC.Internal.Functor.ZipList Methods fmap :: (a -> b) -> ZipList a -> ZipList b Source # (<$) :: a -> ZipList b -> ZipList a Source #
Functor NoIO	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.GHCi Methods fmap :: (a -> b) -> NoIO a -> NoIO b Source # (<$) :: a -> NoIO b -> NoIO a Source #
Functor Par1	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> Par1 a -> Par1 b Source # (<$) :: a -> Par1 b -> Par1 a Source #
Functor P	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Text.ParserCombinators.ReadP Methods fmap :: (a -> b) -> P a -> P b Source # (<$) :: a -> P b -> P a Source #
Functor ReadP	Since: base-2.1
Instance details Defined in GHC.Internal.Text.ParserCombinators.ReadP Methods fmap :: (a -> b) -> ReadP a -> ReadP b Source # (<$) :: a -> ReadP b -> ReadP a Source #
Functor ReadPrec	Since: base-2.1
Instance details Defined in GHC.Internal.Text.ParserCombinators.ReadPrec Methods fmap :: (a -> b) -> ReadPrec a -> ReadPrec b Source # (<$) :: a -> ReadPrec b -> ReadPrec a Source #
Functor IO	Since: base-2.1
Instance details Defined in GHC.Internal.Base Methods fmap :: (a -> b) -> IO a -> IO b Source # (<$) :: a -> IO b -> IO a Source #
Functor Maybe	Since: base-2.1
Instance details Defined in GHC.Internal.Base Methods fmap :: (a -> b) -> Maybe a -> Maybe b Source # (<$) :: a -> Maybe b -> Maybe a Source #
Functor Solo	Since: base-4.15
Instance details Defined in GHC.Internal.Base Methods fmap :: (a -> b) -> Solo a -> Solo b Source # (<$) :: a -> Solo b -> Solo a Source #
Functor []	Since: base-2.1
Instance details Defined in GHC.Internal.Base Methods fmap :: (a -> b) -> [a] -> [b] Source # (<$) :: a -> [b] -> [a] Source #
Monad m => Functor (WrappedMonad m) Source #	Since: base-2.1
Instance details Defined in Control.Applicative Methods fmap :: (a -> b) -> WrappedMonad m a -> WrappedMonad m b Source # (<$) :: a -> WrappedMonad m b -> WrappedMonad m a Source #
Functor (Arg a) Source #	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods fmap :: (a0 -> b) -> Arg a a0 -> Arg a b Source # (<$) :: a0 -> Arg a b -> Arg a a0 Source #
Functor (Array i)	Since: base-2.1
Instance details Defined in GHC.Internal.Arr Methods fmap :: (a -> b) -> Array i a -> Array i b Source # (<$) :: a -> Array i b -> Array i a Source #
Arrow a => Functor (ArrowMonad a)	Since: base-4.6.0.0
Instance details Defined in GHC.Internal.Control.Arrow Methods fmap :: (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b Source # (<$) :: a0 -> ArrowMonad a b -> ArrowMonad a a0 Source #
Functor (ST s)	Since: base-2.1
Instance details Defined in GHC.Internal.Control.Monad.ST.Lazy.Imp Methods fmap :: (a -> b) -> ST s a -> ST s b Source # (<$) :: a -> ST s b -> ST s a Source #
Functor (Either a)	Since: base-3.0
Instance details Defined in GHC.Internal.Data.Either Methods fmap :: (a0 -> b) -> Either a a0 -> Either a b Source # (<$) :: a0 -> Either a b -> Either a a0 Source #
Functor (StateL s)	Since: base-4.0
Instance details Defined in GHC.Internal.Data.Functor.Utils Methods fmap :: (a -> b) -> StateL s a -> StateL s b Source # (<$) :: a -> StateL s b -> StateL s a Source #
Functor (StateR s)	Since: base-4.0
Instance details Defined in GHC.Internal.Data.Functor.Utils Methods fmap :: (a -> b) -> StateR s a -> StateR s b Source # (<$) :: a -> StateR s b -> StateR s a Source #
Functor (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in GHC.Internal.Data.Proxy Methods fmap :: (a -> b) -> Proxy a -> Proxy b Source # (<$) :: a -> Proxy b -> Proxy a Source #
Functor (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> U1 a -> U1 b Source # (<$) :: a -> U1 b -> U1 a Source #
Functor (V1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> V1 a -> V1 b Source # (<$) :: a -> V1 b -> V1 a Source #
Functor (ST s)	Since: base-2.1
Instance details Defined in GHC.Internal.ST Methods fmap :: (a -> b) -> ST s a -> ST s b Source # (<$) :: a -> ST s b -> ST s a Source #
Functor ((,) a)	Since: base-2.1
Instance details Defined in GHC.Internal.Base Methods fmap :: (a0 -> b) -> (a, a0) -> (a, b) Source # (<$) :: a0 -> (a, b) -> (a, a0) Source #
Arrow a => Functor (WrappedArrow a b) Source #	Since: base-2.1
Instance details Defined in Control.Applicative Methods fmap :: (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 Source # (<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 Source #
Functor m => Functor (Kleisli m a)	Since: base-4.14.0.0
Instance details Defined in GHC.Internal.Control.Arrow Methods fmap :: (a0 -> b) -> Kleisli m a a0 -> Kleisli m a b Source # (<$) :: a0 -> Kleisli m a b -> Kleisli m a a0 Source #
Functor (Const m :: Type -> Type)	Since: base-2.1
Instance details Defined in GHC.Internal.Data.Functor.Const Methods fmap :: (a -> b) -> Const m a -> Const m b Source # (<$) :: a -> Const m b -> Const m a Source #
Monad m => Functor (StateT s m)	Since: base-4.18.0.0
Instance details Defined in GHC.Internal.Data.Functor.Utils Methods fmap :: (a -> b) -> StateT s m a -> StateT s m b Source # (<$) :: a -> StateT s m b -> StateT s m a Source #
Functor f => Functor (Ap f)	Since: base-4.12.0.0
Instance details Defined in GHC.Internal.Data.Monoid Methods fmap :: (a -> b) -> Ap f a -> Ap f b Source # (<$) :: a -> Ap f b -> Ap f a Source #
Functor f => Functor (Alt f)	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Semigroup.Internal Methods fmap :: (a -> b) -> Alt f a -> Alt f b Source # (<$) :: a -> Alt f b -> Alt f a Source #
(Generic1 f, Functor (Rep1 f)) => Functor (Generically1 f)	Since: base-4.17.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> Generically1 f a -> Generically1 f b Source # (<$) :: a -> Generically1 f b -> Generically1 f a Source #
Functor f => Functor (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> Rec1 f a -> Rec1 f b Source # (<$) :: a -> Rec1 f b -> Rec1 f a Source #
Functor (URec (Ptr ()) :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> URec (Ptr ()) a -> URec (Ptr ()) b Source # (<$) :: a -> URec (Ptr ()) b -> URec (Ptr ()) a Source #
Functor (URec Char :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> URec Char a -> URec Char b Source # (<$) :: a -> URec Char b -> URec Char a Source #
Functor (URec Double :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> URec Double a -> URec Double b Source # (<$) :: a -> URec Double b -> URec Double a Source #
Functor (URec Float :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> URec Float a -> URec Float b Source # (<$) :: a -> URec Float b -> URec Float a Source #
Functor (URec Int :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> URec Int a -> URec Int b Source # (<$) :: a -> URec Int b -> URec Int a Source #
Functor (URec Word :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> URec Word a -> URec Word b Source # (<$) :: a -> URec Word b -> URec Word a Source #
Functor ((,,) a b)	Since: base-4.14.0.0
Instance details Defined in GHC.Internal.Base Methods fmap :: (a0 -> b0) -> (a, b, a0) -> (a, b, b0) Source # (<$) :: a0 -> (a, b, b0) -> (a, b, a0) Source #
(Functor f, Functor g) => Functor (Product f g) Source #	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods fmap :: (a -> b) -> Product f g a -> Product f g b Source # (<$) :: a -> Product f g b -> Product f g a Source #
(Functor f, Functor g) => Functor (Sum f g) Source #	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Sum Methods fmap :: (a -> b) -> Sum f g a -> Sum f g b Source # (<$) :: a -> Sum f g b -> Sum f g a Source #
(Functor f, Functor g) => Functor (f :*: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> (f :: g) a -> (f :: g) b Source # (<$) :: a -> (f :: g) b -> (f :: g) a Source #
(Functor f, Functor g) => Functor (f :+: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> (f :+: g) a -> (f :+: g) b Source # (<$) :: a -> (f :+: g) b -> (f :+: g) a Source #
Functor (K1 i c :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> K1 i c a -> K1 i c b Source # (<$) :: a -> K1 i c b -> K1 i c a Source #
Functor ((,,,) a b c)	Since: base-4.14.0.0
Instance details Defined in GHC.Internal.Base Methods fmap :: (a0 -> b0) -> (a, b, c, a0) -> (a, b, c, b0) Source # (<$) :: a0 -> (a, b, c, b0) -> (a, b, c, a0) Source #
Functor ((->) r)	Since: base-2.1
Instance details Defined in GHC.Internal.Base Methods fmap :: (a -> b) -> (r -> a) -> r -> b Source # (<$) :: a -> (r -> b) -> r -> a Source #
(Functor f, Functor g) => Functor (Compose f g) Source #	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods fmap :: (a -> b) -> Compose f g a -> Compose f g b Source # (<$) :: a -> Compose f g b -> Compose f g a Source #
(Functor f, Functor g) => Functor (f :.: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> (f :.: g) a -> (f :.: g) b Source # (<$) :: a -> (f :.: g) b -> (f :.: g) a Source #
Functor f => Functor (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods fmap :: (a -> b) -> M1 i c f a -> M1 i c f b Source # (<$) :: a -> M1 i c f b -> M1 i c f a Source #
Functor ((,,,,) a b c d)	Since: base-4.18.0.0
Instance details Defined in GHC.Internal.Base Methods fmap :: (a0 -> b0) -> (a, b, c, d, a0) -> (a, b, c, d, b0) Source # (<$) :: a0 -> (a, b, c, d, b0) -> (a, b, c, d, a0) Source #
Functor ((,,,,,) a b c d e)	Since: base-4.18.0.0
Instance details Defined in GHC.Internal.Base Methods fmap :: (a0 -> b0) -> (a, b, c, d, e, a0) -> (a, b, c, d, e, b0) Source # (<$) :: a0 -> (a, b, c, d, e, b0) -> (a, b, c, d, e, a0) Source #
Functor ((,,,,,,) a b c d e f)	Since: base-4.18.0.0
Instance details Defined in GHC.Internal.Base Methods fmap :: (a0 -> b0) -> (a, b, c, d, e, f, a0) -> (a, b, c, d, e, f, b0) Source # (<$) :: a0 -> (a, b, c, d, e, f, b0) -> (a, b, c, d, e, f, a0) Source #

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

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 List, Maybe and IO defined in the Prelude satisfy these laws.

Minimal complete definition

(>>=)

Methods

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

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

An alternative name for this function is 'bind', but some people may refer to it as 'flatMap', which results from it being equivialent to

\x f -> join (fmap f x) :: Monad m => m a -> (a -> m b) -> m b

which can be seen as mapping a value with Monad m => m a -> m (m b) and then 'flattening' m (m b) to m b using join.

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

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

or in terms of (>>=) as

as >>= const bs

return :: a -> m a Source #

Inject a value into the monadic type. This function should not be different from its default implementation as pure. The justification for the existence of this function is merely historic.

Instances

Instances details

Monad Complex Source #	Since: base-4.9.0.0
Instance details Defined in Data.Complex Methods (>>=) :: Complex a -> (a -> Complex b) -> Complex b Source # (>>) :: Complex a -> Complex b -> Complex b Source # return :: a -> Complex a Source #
Monad First Source #	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: First a -> (a -> First b) -> First b Source # (>>) :: First a -> First b -> First b Source # return :: a -> First a Source #
Monad Last Source #	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Last a -> (a -> Last b) -> Last b Source # (>>) :: Last a -> Last b -> Last b Source # return :: a -> Last a Source #
Monad Max Source #	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Max a -> (a -> Max b) -> Max b Source # (>>) :: Max a -> Max b -> Max b Source # return :: a -> Max a Source #
Monad Min Source #	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods (>>=) :: Min a -> (a -> Min b) -> Min b Source # (>>) :: Min a -> Min b -> Min b Source # return :: a -> Min a Source #
Monad NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Base Methods (>>=) :: NonEmpty a -> (a -> NonEmpty b) -> NonEmpty b Source # (>>) :: NonEmpty a -> NonEmpty b -> NonEmpty b Source # return :: a -> NonEmpty a Source #
Monad STM	Since: base-4.3.0.0
Instance details Defined in GHC.Internal.Conc.Sync Methods (>>=) :: STM a -> (a -> STM b) -> STM b Source # (>>) :: STM a -> STM b -> STM b Source # return :: a -> STM a Source #
Monad Identity	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Functor.Identity Methods (>>=) :: Identity a -> (a -> Identity b) -> Identity b Source # (>>) :: Identity a -> Identity b -> Identity b Source # return :: a -> Identity a Source #
Monad First	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Monoid Methods (>>=) :: First a -> (a -> First b) -> First b Source # (>>) :: First a -> First b -> First b Source # return :: a -> First a Source #
Monad Last	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Monoid Methods (>>=) :: Last a -> (a -> Last b) -> Last b Source # (>>) :: Last a -> Last b -> Last b Source # return :: a -> Last a Source #
Monad Down	Since: base-4.11.0.0
Instance details Defined in GHC.Internal.Data.Ord Methods (>>=) :: Down a -> (a -> Down b) -> Down b Source # (>>) :: Down a -> Down b -> Down b Source # return :: a -> Down a Source #
Monad Dual	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Semigroup.Internal Methods (>>=) :: Dual a -> (a -> Dual b) -> Dual b Source # (>>) :: Dual a -> Dual b -> Dual b Source # return :: a -> Dual a Source #
Monad Product	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Semigroup.Internal Methods (>>=) :: Product a -> (a -> Product b) -> Product b Source # (>>) :: Product a -> Product b -> Product b Source # return :: a -> Product a Source #
Monad Sum	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Semigroup.Internal Methods (>>=) :: Sum a -> (a -> Sum b) -> Sum b Source # (>>) :: Sum a -> Sum b -> Sum b Source # return :: a -> Sum a Source #
Monad NoIO	Since: base-4.4.0.0
Instance details Defined in GHC.Internal.GHCi Methods (>>=) :: NoIO a -> (a -> NoIO b) -> NoIO b Source # (>>) :: NoIO a -> NoIO b -> NoIO b Source # return :: a -> NoIO a Source #
Monad Par1	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods (>>=) :: Par1 a -> (a -> Par1 b) -> Par1 b Source # (>>) :: Par1 a -> Par1 b -> Par1 b Source # return :: a -> Par1 a Source #
Monad P	Since: base-2.1
Instance details Defined in GHC.Internal.Text.ParserCombinators.ReadP Methods (>>=) :: P a -> (a -> P b) -> P b Source # (>>) :: P a -> P b -> P b Source # return :: a -> P a Source #
Monad ReadP	Since: base-2.1
Instance details Defined in GHC.Internal.Text.ParserCombinators.ReadP Methods (>>=) :: ReadP a -> (a -> ReadP b) -> ReadP b Source # (>>) :: ReadP a -> ReadP b -> ReadP b Source # return :: a -> ReadP a Source #
Monad ReadPrec	Since: base-2.1
Instance details Defined in GHC.Internal.Text.ParserCombinators.ReadPrec Methods (>>=) :: ReadPrec a -> (a -> ReadPrec b) -> ReadPrec b Source # (>>) :: ReadPrec a -> ReadPrec b -> ReadPrec b Source # return :: a -> ReadPrec a Source #
Monad IO	Since: base-2.1
Instance details Defined in GHC.Internal.Base Methods (>>=) :: IO a -> (a -> IO b) -> IO b Source # (>>) :: IO a -> IO b -> IO b Source # return :: a -> IO a Source #
Monad Maybe	Since: base-2.1
Instance details Defined in GHC.Internal.Base Methods (>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b Source # (>>) :: Maybe a -> Maybe b -> Maybe b Source # return :: a -> Maybe a Source #
Monad Solo	Since: base-4.15
Instance details Defined in GHC.Internal.Base Methods (>>=) :: Solo a -> (a -> Solo b) -> Solo b Source # (>>) :: Solo a -> Solo b -> Solo b Source # return :: a -> Solo a Source #
Monad []	Since: base-2.1
Instance details Defined in GHC.Internal.Base Methods (>>=) :: [a] -> (a -> [b]) -> [b] Source # (>>) :: [a] -> [b] -> [b] Source # return :: a -> [a] Source #
Monad m => Monad (WrappedMonad m) Source #	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods (>>=) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b Source # (>>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b Source # return :: a -> WrappedMonad m a Source #
ArrowApply a => Monad (ArrowMonad a)	Since: base-2.1
Instance details Defined in GHC.Internal.Control.Arrow Methods (>>=) :: ArrowMonad a a0 -> (a0 -> ArrowMonad a b) -> ArrowMonad a b Source # (>>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b Source # return :: a0 -> ArrowMonad a a0 Source #
Monad (ST s)	Since: base-2.1
Instance details Defined in GHC.Internal.Control.Monad.ST.Lazy.Imp Methods (>>=) :: ST s a -> (a -> ST s b) -> ST s b Source # (>>) :: ST s a -> ST s b -> ST s b Source # return :: a -> ST s a Source #
Monad (Either e)	Since: base-4.4.0.0
Instance details Defined in GHC.Internal.Data.Either Methods (>>=) :: Either e a -> (a -> Either e b) -> Either e b Source # (>>) :: Either e a -> Either e b -> Either e b Source # return :: a -> Either e a Source #
Monad (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in GHC.Internal.Data.Proxy Methods (>>=) :: Proxy a -> (a -> Proxy b) -> Proxy b Source # (>>) :: Proxy a -> Proxy b -> Proxy b Source # return :: a -> Proxy a Source #
Monad (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods (>>=) :: U1 a -> (a -> U1 b) -> U1 b Source # (>>) :: U1 a -> U1 b -> U1 b Source # return :: a -> U1 a Source #
Monad (ST s)	Since: base-2.1
Instance details Defined in GHC.Internal.ST Methods (>>=) :: ST s a -> (a -> ST s b) -> ST s b Source # (>>) :: ST s a -> ST s b -> ST s b Source # return :: a -> ST s a Source #
Monoid a => Monad ((,) a)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Base Methods (>>=) :: (a, a0) -> (a0 -> (a, b)) -> (a, b) Source # (>>) :: (a, a0) -> (a, b) -> (a, b) Source # return :: a0 -> (a, a0) Source #
Monad m => Monad (Kleisli m a)	Since: base-4.14.0.0
Instance details Defined in GHC.Internal.Control.Arrow Methods (>>=) :: Kleisli m a a0 -> (a0 -> Kleisli m a b) -> Kleisli m a b Source # (>>) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a b Source # return :: a0 -> Kleisli m a a0 Source #
Monad m => Monad (StateT s m)	Since: base-4.18.0.0
Instance details Defined in GHC.Internal.Data.Functor.Utils Methods (>>=) :: StateT s m a -> (a -> StateT s m b) -> StateT s m b Source # (>>) :: StateT s m a -> StateT s m b -> StateT s m b Source # return :: a -> StateT s m a Source #
Monad f => Monad (Ap f)	Since: base-4.12.0.0
Instance details Defined in GHC.Internal.Data.Monoid Methods (>>=) :: Ap f a -> (a -> Ap f b) -> Ap f b Source # (>>) :: Ap f a -> Ap f b -> Ap f b Source # return :: a -> Ap f a Source #
Monad f => Monad (Alt f)	Since: base-4.8.0.0
Instance details Defined in GHC.Internal.Data.Semigroup.Internal Methods (>>=) :: Alt f a -> (a -> Alt f b) -> Alt f b Source # (>>) :: Alt f a -> Alt f b -> Alt f b Source # return :: a -> Alt f a Source #
Monad f => Monad (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods (>>=) :: Rec1 f a -> (a -> Rec1 f b) -> Rec1 f b Source # (>>) :: Rec1 f a -> Rec1 f b -> Rec1 f b Source # return :: a -> Rec1 f a Source #
(Monoid a, Monoid b) => Monad ((,,) a b)	Since: base-4.14.0.0
Instance details Defined in GHC.Internal.Base Methods (>>=) :: (a, b, a0) -> (a0 -> (a, b, b0)) -> (a, b, b0) Source # (>>) :: (a, b, a0) -> (a, b, b0) -> (a, b, b0) Source # return :: a0 -> (a, b, a0) Source #
(Monad f, Monad g) => Monad (Product f g) Source #	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods (>>=) :: Product f g a -> (a -> Product f g b) -> Product f g b Source # (>>) :: Product f g a -> Product f g b -> Product f g b Source # return :: a -> Product f g a Source #
(Monad f, Monad g) => Monad (f :*: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods (>>=) :: (f :: g) a -> (a -> (f :: g) b) -> (f :: g) b Source # (>>) :: (f :: g) a -> (f :: g) b -> (f :: g) b Source # return :: a -> (f :*: g) a Source #
(Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c)	Since: base-4.14.0.0
Instance details Defined in GHC.Internal.Base Methods (>>=) :: (a, b, c, a0) -> (a0 -> (a, b, c, b0)) -> (a, b, c, b0) Source # (>>) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, b0) Source # return :: a0 -> (a, b, c, a0) Source #
Monad ((->) r)	Since: base-2.1
Instance details Defined in GHC.Internal.Base Methods (>>=) :: (r -> a) -> (a -> r -> b) -> r -> b Source # (>>) :: (r -> a) -> (r -> b) -> r -> b Source # return :: a -> r -> a Source #
Monad f => Monad (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in GHC.Internal.Generics Methods (>>=) :: M1 i c f a -> (a -> M1 i c f b) -> M1 i c f b Source # (>>) :: M1 i c f a -> M1 i c f b -> M1 i c f b Source # return :: a -> M1 i c f a Source #