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/Haskell 9

Control.Monad.Trans.Identity

Copyright (c) 2007 Magnus Therning
License BSD-style (see the file LICENSE)
Maintainer [email protected]
Stability experimental
Portability portable
Safe Haskell Safe
Language Haskell2010

Description

The identity monad transformer.

This is useful for functions parameterized by a monad transformer.

The identity monad transformer

newtype IdentityT (f :: k -> Type) (a :: k) Source

The trivial monad transformer, which maps a monad to an equivalent monad.

Constructors

IdentityT

Fields

Instances
Instances details
Generic1 (IdentityT f :: k -> Type) Source
Instance details

Defined in Control.Monad.Trans.Identity

Associated Types

type Rep1 (IdentityT f :: k -> Type)
Instance details

Defined in Control.Monad.Trans.Identity

type Rep1 (IdentityT f :: k -> Type) = D1 ('MetaData "IdentityT" "Control.Monad.Trans.Identity" "transformers-0.6.1.2-72bd" 'True) (C1 ('MetaCons "IdentityT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runIdentityT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 f)))

Methods

from1 :: forall (a :: k). IdentityT f a -> Rep1 (IdentityT f) a

to1 :: forall (a :: k). Rep1 (IdentityT f) a -> IdentityT f a

MonadTrans (IdentityT :: (Type -> Type) -> Type -> Type) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

lift :: Monad m => m a -> IdentityT m a Source

Foldable1 m => Foldable1 (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

fold1 :: Semigroup m0 => IdentityT m m0 -> m0 Source

foldMap1 :: Semigroup m0 => (a -> m0) -> IdentityT m a -> m0 Source

foldMap1' :: Semigroup m0 => (a -> m0) -> IdentityT m a -> m0 Source

toNonEmpty :: IdentityT m a -> NonEmpty a Source

maximum :: Ord a => IdentityT m a -> a Source

minimum :: Ord a => IdentityT m a -> a Source

head :: IdentityT m a -> a Source

last :: IdentityT m a -> a Source

foldrMap1 :: (a -> b) -> (a -> b -> b) -> IdentityT m a -> b Source

foldlMap1' :: (a -> b) -> (b -> a -> b) -> IdentityT m a -> b Source

foldlMap1 :: (a -> b) -> (b -> a -> b) -> IdentityT m a -> b Source

foldrMap1' :: (a -> b) -> (a -> b -> b) -> IdentityT m a -> b Source

Eq1 f => Eq1 (IdentityT f) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

liftEq :: (a -> b -> Bool) -> IdentityT f a -> IdentityT f b -> Bool Source

Ord1 f => Ord1 (IdentityT f) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

liftCompare :: (a -> b -> Ordering) -> IdentityT f a -> IdentityT f b -> Ordering Source

Read1 f => Read1 (IdentityT f) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (IdentityT f a) Source

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [IdentityT f a] Source

liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (IdentityT f a) Source

liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [IdentityT f a] Source

Show1 f => Show1 (IdentityT f) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> IdentityT f a -> ShowS Source

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [IdentityT f a] -> ShowS Source

Contravariant f => Contravariant (IdentityT f) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

contramap :: (a' -> a) -> IdentityT f a -> IdentityT f a' Source

(>$) :: b -> IdentityT f b -> IdentityT f a Source

Alternative m => Alternative (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

empty :: IdentityT m a

(<|>) :: IdentityT m a -> IdentityT m a -> IdentityT m a

some :: IdentityT m a -> IdentityT m [a]

many :: IdentityT m a -> IdentityT m [a]

Applicative m => Applicative (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

pure :: a -> IdentityT m a

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

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

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

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

Functor m => Functor (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

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

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

Monad m => Monad (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

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

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

return :: a -> IdentityT m a

MonadPlus m => MonadPlus (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

mzero :: IdentityT m a

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

MonadFail m => MonadFail (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

fail :: String -> IdentityT m a

MonadFix m => MonadFix (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

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

MonadIO m => MonadIO (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

liftIO :: IO a -> IdentityT m a

MonadZip m => MonadZip (IdentityT m) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

mzip :: IdentityT m a -> IdentityT m b -> IdentityT m (a, b)

mzipWith :: (a -> b -> c) -> IdentityT m a -> IdentityT m b -> IdentityT m c

munzip :: IdentityT m (a, b) -> (IdentityT m a, IdentityT m b)

Foldable f => Foldable (IdentityT f) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

fold :: Monoid m => IdentityT f m -> m

foldMap :: Monoid m => (a -> m) -> IdentityT f a -> m

foldMap' :: Monoid m => (a -> m) -> IdentityT f a -> m

foldr :: (a -> b -> b) -> b -> IdentityT f a -> b

foldr' :: (a -> b -> b) -> b -> IdentityT f a -> b

foldl :: (b -> a -> b) -> b -> IdentityT f a -> b

foldl' :: (b -> a -> b) -> b -> IdentityT f a -> b

foldr1 :: (a -> a -> a) -> IdentityT f a -> a

foldl1 :: (a -> a -> a) -> IdentityT f a -> a

toList :: IdentityT f a -> [a]

null :: IdentityT f a -> Bool

length :: IdentityT f a -> Int

elem :: Eq a => a -> IdentityT f a -> Bool

maximum :: Ord a => IdentityT f a -> a

minimum :: Ord a => IdentityT f a -> a

sum :: Num a => IdentityT f a -> a

product :: Num a => IdentityT f a -> a

Traversable f => Traversable (IdentityT f) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

traverse :: Applicative f0 => (a -> f0 b) -> IdentityT f a -> f0 (IdentityT f b)

sequenceA :: Applicative f0 => IdentityT f (f0 a) -> f0 (IdentityT f a)

mapM :: Monad m => (a -> m b) -> IdentityT f a -> m (IdentityT f b)

sequence :: Monad m => IdentityT f (m a) -> m (IdentityT f a)

Generic (IdentityT f a) Source
Instance details

Defined in Control.Monad.Trans.Identity

Associated Types

type Rep (IdentityT f a)
Instance details

Defined in Control.Monad.Trans.Identity

type Rep (IdentityT f a) = D1 ('MetaData "IdentityT" "Control.Monad.Trans.Identity" "transformers-0.6.1.2-72bd" 'True) (C1 ('MetaCons "IdentityT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runIdentityT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (f a))))

Methods

from :: IdentityT f a -> Rep (IdentityT f a) x

to :: Rep (IdentityT f a) x -> IdentityT f a

(Read1 f, Read a) => Read (IdentityT f a) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

readsPrec :: Int -> ReadS (IdentityT f a)

readList :: ReadS [IdentityT f a]

readPrec :: ReadPrec (IdentityT f a)

readListPrec :: ReadPrec [IdentityT f a]

(Show1 f, Show a) => Show (IdentityT f a) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

showsPrec :: Int -> IdentityT f a -> ShowS

show :: IdentityT f a -> String

showList :: [IdentityT f a] -> ShowS

(Eq1 f, Eq a) => Eq (IdentityT f a) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

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

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

(Ord1 f, Ord a) => Ord (IdentityT f a) Source
Instance details

Defined in Control.Monad.Trans.Identity

Methods

compare :: IdentityT f a -> IdentityT f a -> Ordering

(<) :: IdentityT f a -> IdentityT f a -> Bool

(<=) :: IdentityT f a -> IdentityT f a -> Bool

(>) :: IdentityT f a -> IdentityT f a -> Bool

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

max :: IdentityT f a -> IdentityT f a -> IdentityT f a

min :: IdentityT f a -> IdentityT f a -> IdentityT f a

type Rep1 (IdentityT f :: k -> Type) Source
Instance details

Defined in Control.Monad.Trans.Identity

type Rep1 (IdentityT f :: k -> Type) = D1 ('MetaData "IdentityT" "Control.Monad.Trans.Identity" "transformers-0.6.1.2-72bd" 'True) (C1 ('MetaCons "IdentityT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runIdentityT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 f)))
type Rep (IdentityT f a) Source
Instance details

Defined in Control.Monad.Trans.Identity

type Rep (IdentityT f a) = D1 ('MetaData "IdentityT" "Control.Monad.Trans.Identity" "transformers-0.6.1.2-72bd" 'True) (C1 ('MetaCons "IdentityT" 'PrefixI 'True) (S1 ('MetaSel ('Just "runIdentityT") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (f a))))

mapIdentityT :: forall {k1} {k2} m (a :: k1) n (b :: k2). (m a -> n b) -> IdentityT m a -> IdentityT n b Source

Lift a unary operation to the new monad.

Lifting other operations

liftCatch :: forall {k} e m (a :: k). Catch e m a -> Catch e (IdentityT m) a Source

Lift a catchE operation to the new monad.

liftCallCC :: CallCC m a b -> CallCC (IdentityT m) a b Source

Lift a callCC operation to the new monad.

© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/9.12.1/docs/libraries/transformers-0.6.1.2-72bd/Control-Monad-Trans-Identity.html