Control.Monad.Instances

base-4.16.0.0: Basic libraries

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 | Safe
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 where
  - fmap :: (a -> b) -> f a -> f b
  - (<$) :: a -> f b -> f a
- class Applicative m => Monad m where
  - (>>=) :: forall a b. m a -> (a -> m b) -> m b
  - (>>) :: forall a b. m a -> m b -> m b
  - return :: a -> m a

# Documentation

class Functor f 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.

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.

#### Instances

Instances details

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

class Applicative m => Monad m 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 lists, `Maybe` and `IO` defined in the Prelude satisfy these laws.

Minimal complete definition

(>>=)

Methods

(>>=) :: forall a b. 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

(>>) :: forall a b. 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

return :: a -> m a Source #

Inject a value into the monadic type.

#### Instances

Instances details

Monad Complex # | 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 Identity # | Since: base-4.8.0.0
Instance details Defined in 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 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 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 Data.Ord Methods (>>=) :: Down a -> (a -> Down b) -> Down b Source # (>>) :: Down a -> Down b -> Down b Source # return :: a -> Down a Source #
Monad First # | 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 # | 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 # | 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 # | 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 Dual # | Since: base-4.8.0.0
Instance details Defined in 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 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 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 NonEmpty # | Since: base-4.9.0.0
Instance details Defined in GHC.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.Conc.Sync Methods (>>=) :: STM a -> (a -> STM b) -> STM b Source # (>>) :: STM a -> STM b -> STM b Source # return :: a -> STM a Source #
Monad NoIO # | Since: base-4.4.0.0
Instance details Defined in GHC.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.Generics Methods (>>=) :: Par1 a -> (a -> Par1 b) -> Par1 b Source # (>>) :: Par1 a -> Par1 b -> Par1 b Source # return :: a -> Par1 a Source #
Monad ReadP # | Since: base-2.1
Instance details Defined in 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 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.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.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.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.Base Methods (>>=) :: [a] -> (a -> [b]) -> [b] Source # (>>) :: [a] -> [b] -> [b] Source # return :: a -> [a] Source #
Monad m => Monad (WrappedMonad m) # | Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods (>>=) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b 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 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 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 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 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.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.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.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 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 f => Monad (Ap f) # | Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods (>>=) :: Ap f a -> (a -> Ap f b) -> Ap f b 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 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.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.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) # | 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.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.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.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.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 #