Copyright	(c) Edward Kmett 2011 (c) Conal Elliott 2008
License	BSD3
Maintainer	ekmett@gmail.com
Stability	experimental
Safe Haskell	Safe-Inferred
Language	Haskell2010

Control.Monad.Representable.Reader

Contents

Representable functor monad
Monad Transformer

Description

Representable functors on Hask are all monads, because they are isomorphic to a Reader monad.

Synopsis

type Reader f = ReaderT f Identity
runReader :: Representable f => Reader f b -> Rep f -> b
newtype ReaderT f m b = ReaderT {
- getReaderT :: f (m b)
}
readerT :: Representable f => ( Rep f -> m b) -> ReaderT f m b
runReaderT :: Representable f => ReaderT f m b -> Rep f -> m b
class Monad m => MonadReader r (m :: Type -> Type ) | m -> r where
- ask :: m r
- local :: (r -> r) -> m a -> m a
- reader :: (r -> a) -> m a
module Data.Functor.Rep

Representable functor monad

type Reader f = ReaderT f Identity Source #

runReader :: Representable f => Reader f b -> Rep f -> b Source #

Monad Transformer

newtype ReaderT f m b Source #

Constructors

ReaderT
Fields getReaderT :: f (m b)

Instances

Instances details

( Representable f, MonadWriter w m) => MonadWriter w ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods writer :: (a, w) -> ReaderT f m a Source # tell :: w -> ReaderT f m () Source # listen :: ReaderT f m a -> ReaderT f m (a, w) Source # pass :: ReaderT f m (a, w -> w) -> ReaderT f m a Source #
Representable f => MonadTrans ( ReaderT f) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods lift :: Monad m => m a -> ReaderT f m a Source #
( Representable f, Monad m) => Monad ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods (>>=) :: ReaderT f m a -> (a -> ReaderT f m b) -> ReaderT f m b Source # (>>) :: ReaderT f m a -> ReaderT f m b -> ReaderT f m b Source # return :: a -> ReaderT f m a Source #
( Functor f, Functor m) => Functor ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods fmap :: (a -> b) -> ReaderT f m a -> ReaderT f m b Source # (<$) :: a -> ReaderT f m b -> ReaderT f m a Source #
( Representable f, Applicative m) => Applicative ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods pure :: a -> ReaderT f m a Source # (<>) :: ReaderT f m (a -> b) -> ReaderT f m a -> ReaderT f m b Source # liftA2 :: (a -> b -> c) -> ReaderT f m a -> ReaderT f m b -> ReaderT f m c Source # (>) :: ReaderT f m a -> ReaderT f m b -> ReaderT f m b Source # (<*) :: ReaderT f m a -> ReaderT f m b -> ReaderT f m a Source #
( Foldable f, Foldable m) => Foldable ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods fold :: Monoid m0 => ReaderT f m m0 -> m0 Source # foldMap :: Monoid m0 => (a -> m0) -> ReaderT f m a -> m0 Source # foldMap' :: Monoid m0 => (a -> m0) -> ReaderT f m a -> m0 Source # foldr :: (a -> b -> b) -> b -> ReaderT f m a -> b Source # foldr' :: (a -> b -> b) -> b -> ReaderT f m a -> b Source # foldl :: (b -> a -> b) -> b -> ReaderT f m a -> b Source # foldl' :: (b -> a -> b) -> b -> ReaderT f m a -> b Source # foldr1 :: (a -> a -> a) -> ReaderT f m a -> a Source # foldl1 :: (a -> a -> a) -> ReaderT f m a -> a Source # toList :: ReaderT f m a -> [a] Source # null :: ReaderT f m a -> Bool Source # length :: ReaderT f m a -> Int Source # elem :: Eq a => a -> ReaderT f m a -> Bool Source # maximum :: Ord a => ReaderT f m a -> a Source # minimum :: Ord a => ReaderT f m a -> a Source # sum :: Num a => ReaderT f m a -> a Source # product :: Num a => ReaderT f m a -> a Source #
( Traversable f, Traversable m) => Traversable ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods traverse :: Applicative f0 => (a -> f0 b) -> ReaderT f m a -> f0 ( ReaderT f m b) Source # sequenceA :: Applicative f0 => ReaderT f m (f0 a) -> f0 ( ReaderT f m a) Source # mapM :: Monad m0 => (a -> m0 b) -> ReaderT f m a -> m0 ( ReaderT f m b) Source # sequence :: Monad m0 => ReaderT f m (m0 a) -> m0 ( ReaderT f m a) Source #
( Representable f, MonadIO m) => MonadIO ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods liftIO :: IO a -> ReaderT f m a Source #
( Representable f, Representable m, Monoid ( Rep f), Monoid ( Rep m)) => Comonad ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods extract :: ReaderT f m a -> a Source # duplicate :: ReaderT f m a -> ReaderT f m ( ReaderT f m a) Source # extend :: ( ReaderT f m a -> b) -> ReaderT f m a -> ReaderT f m b Source #
( Representable f, Distributive m) => Distributive ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods distribute :: Functor f0 => f0 ( ReaderT f m a) -> ReaderT f m (f0 a) Source # collect :: Functor f0 => (a -> ReaderT f m b) -> f0 a -> ReaderT f m (f0 b) Source # distributeM :: Monad m0 => m0 ( ReaderT f m a) -> ReaderT f m (m0 a) Source # collectM :: Monad m0 => (a -> ReaderT f m b) -> m0 a -> ReaderT f m (m0 b) Source #
( Traversable1 f, Traversable1 m) => Traversable1 ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods traverse1 :: Apply f0 => (a -> f0 b) -> ReaderT f m a -> f0 ( ReaderT f m b) Source # sequence1 :: Apply f0 => ReaderT f m (f0 b) -> f0 ( ReaderT f m b) Source #
( Representable f, Apply m) => Apply ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods (<.>) :: ReaderT f m (a -> b) -> ReaderT f m a -> ReaderT f m b Source # (.>) :: ReaderT f m a -> ReaderT f m b -> ReaderT f m b Source # (<.) :: ReaderT f m a -> ReaderT f m b -> ReaderT f m a Source # liftF2 :: (a -> b -> c) -> ReaderT f m a -> ReaderT f m b -> ReaderT f m c Source #
( Representable f, Bind m) => Bind ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods (>>-) :: ReaderT f m a -> (a -> ReaderT f m b) -> ReaderT f m b Source # join :: ReaderT f m ( ReaderT f m a) -> ReaderT f m a Source #
( Foldable1 f, Foldable1 m) => Foldable1 ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods fold1 :: Semigroup m0 => ReaderT f m m0 -> m0 Source # foldMap1 :: Semigroup m0 => (a -> m0) -> ReaderT f m a -> m0 Source # toNonEmpty :: ReaderT f m a -> NonEmpty a Source #
( Representable f, Representable m, Semigroup ( Rep f), Semigroup ( Rep m)) => Extend ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Methods duplicated :: ReaderT f m a -> ReaderT f m ( ReaderT f m a) Source # extended :: ( ReaderT f m a -> b) -> ReaderT f m a -> ReaderT f m b Source #
( Representable f, Representable m) => Representable ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader Associated Types type Rep ( ReaderT f m) Source # Methods tabulate :: ( Rep ( ReaderT f m) -> a) -> ReaderT f m a Source # index :: ReaderT f m a -> Rep ( ReaderT f m) -> a Source #
type Rep ( ReaderT f m) Source #
Instance details Defined in Control.Monad.Representable.Reader type Rep ( ReaderT f m) = ( Rep f, Rep m)

readerT :: Representable f => ( Rep f -> m b) -> ReaderT f m b Source #

runReaderT :: Representable f => ReaderT f m b -> Rep f -> m b Source #

class Monad m => MonadReader r (m :: Type -> Type ) | m -> r where Source #

See examples in Control.Monad.Reader . Note, the partially applied function type (->) r is a simple reader monad. See the instance declaration below.

Minimal complete definition

( ask | reader ), local

Methods

ask :: m r Source #

Retrieves the monad environment.

local Source #

Arguments

:: (r -> r)	The function to modify the environment.
-> m a	`Reader` to run in the modified environment.
-> m a

Executes a computation in a modified environment.

reader Source #

Arguments

:: (r -> a)	The selector function to apply to the environment.
-> m a

Retrieves a function of the current environment.

Instances

Instances details

( Representable f, Rep f ~ a) => MonadReader a ( Co f) Source #
Instance details Defined in Data.Functor.Rep Methods ask :: Co f a Source # local :: (a -> a) -> Co f a0 -> Co f a0 Source # reader :: (a -> a0) -> Co f a0 Source #
( Functor m, MonadReader e m) => MonadReader e ( Free m)
Instance details Defined in Control.Monad.Free Methods ask :: Free m e Source # local :: (e -> e) -> Free m a -> Free m a Source # reader :: (e -> a) -> Free m a Source #
MonadReader r m => MonadReader r ( MaybeT m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: MaybeT m r Source # local :: (r -> r) -> MaybeT m a -> MaybeT m a Source # reader :: (r -> a) -> MaybeT m a Source #
MonadReader r m => MonadReader r ( ListT m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: ListT m r Source # local :: (r -> r) -> ListT m a -> ListT m a Source # reader :: (r -> a) -> ListT m a Source #
( Representable g, MonadReader e m) => MonadReader e ( StateT g m) Source #
Instance details Defined in Control.Monad.Representable.State Methods ask :: StateT g m e Source # local :: (e -> e) -> StateT g m a -> StateT g m a Source # reader :: (e -> a) -> StateT g m a Source #
( Functor f, Functor m, MonadReader r m) => MonadReader r ( FreeT f m)
Instance details Defined in Control.Monad.Trans.Free Methods ask :: FreeT f m r Source # local :: (r -> r) -> FreeT f m a -> FreeT f m a Source # reader :: (r -> a) -> FreeT f m a Source #
( Monoid w, MonadReader r m) => MonadReader r ( WriterT w m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: WriterT w m r Source # local :: (r -> r) -> WriterT w m a -> WriterT w m a Source # reader :: (r -> a) -> WriterT w m a Source #
( Monoid w, MonadReader r m) => MonadReader r ( WriterT w m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: WriterT w m r Source # local :: (r -> r) -> WriterT w m a -> WriterT w m a Source # reader :: (r -> a) -> WriterT w m a Source #
MonadReader r m => MonadReader r ( StateT s m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: StateT s m r Source # local :: (r -> r) -> StateT s m a -> StateT s m a Source # reader :: (r -> a) -> StateT s m a Source #
MonadReader r m => MonadReader r ( StateT s m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: StateT s m r Source # local :: (r -> r) -> StateT s m a -> StateT s m a Source # reader :: (r -> a) -> StateT s m a Source #
Monad m => MonadReader r ( ReaderT r m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: ReaderT r m r Source # local :: (r -> r) -> ReaderT r m a -> ReaderT r m a Source # reader :: (r -> a) -> ReaderT r m a Source #
MonadReader r m => MonadReader r ( IdentityT m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: IdentityT m r Source # local :: (r -> r) -> IdentityT m a -> IdentityT m a Source # reader :: (r -> a) -> IdentityT m a Source #
MonadReader r m => MonadReader r ( ExceptT e m)	Since: mtl-2.2
Instance details Defined in Control.Monad.Reader.Class Methods ask :: ExceptT e m r Source # local :: (r -> r) -> ExceptT e m a -> ExceptT e m a Source # reader :: (r -> a) -> ExceptT e m a Source #
( Error e, MonadReader r m) => MonadReader r ( ErrorT e m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: ErrorT e m r Source # local :: (r -> r) -> ErrorT e m a -> ErrorT e m a Source # reader :: (r -> a) -> ErrorT e m a Source #
MonadReader r ((->) r :: Type -> Type )
Instance details Defined in Control.Monad.Reader.Class Methods ask :: r -> r Source # local :: (r -> r) -> (r -> a) -> r -> a Source # reader :: (r -> a) -> r -> a Source #
MonadReader r' m => MonadReader r' ( ContT r m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: ContT r m r' Source # local :: (r' -> r') -> ContT r m a -> ContT r m a Source # reader :: (r' -> a) -> ContT r m a Source #
( Monad m, Monoid w) => MonadReader r ( RWST r w s m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: RWST r w s m r Source # local :: (r -> r) -> RWST r w s m a -> RWST r w s m a Source # reader :: (r -> a) -> RWST r w s m a Source #
( Monad m, Monoid w) => MonadReader r ( RWST r w s m)
Instance details Defined in Control.Monad.Reader.Class Methods ask :: RWST r w s m r Source # local :: (r -> r) -> RWST r w s m a -> RWST r w s m a Source # reader :: (r -> a) -> RWST r w s m a Source #

module Data.Functor.Rep