dunai-0.9.2: Generalised reactive framework supporting classic, arrowized and monadic FRP.
Copyright(c) Ivan Perez and Manuel Baerenz 2016
LicenseBSD3
Maintainerivan.perez@keera.co.uk
Safe HaskellSafe-Inferred
LanguageHaskell2010

Control.Monad.Trans.MSF.Reader

Description

MSFs with a Reader monadic layer.

This module contains functions to work with MSFs that include a Reader monadic layer. This includes functions to create new MSFs that include an additional layer, and functions to flatten that layer out of the MSF's transformer stack.

Synopsis

Documentation

mapReader :: (a -> b) -> Reader r a -> Reader r b #

Transform the value returned by a Reader.

mapReaderT :: (m a -> n b) -> ReaderT r m a -> ReaderT r n b #

Transform the computation inside a ReaderT.

runReader #

Arguments

:: Reader r a

A Reader to run.

-> r

An initial environment.

-> a 

Runs a Reader and extracts the final value from it. (The inverse of reader.)

withReader #

Arguments

:: (r' -> r)

The function to modify the environment.

-> Reader r a

Computation to run in the modified environment.

-> Reader r' a 

Execute a computation in a modified environment (a specialization of withReaderT).

withReaderT #

Arguments

:: forall r' r (m :: Type -> Type) a. (r' -> r)

The function to modify the environment.

-> ReaderT r m a

Computation to run in the modified environment.

-> ReaderT r' m a 

Execute a computation in a modified environment (a more general version of local).

type Reader r = ReaderT r Identity #

The parameterizable reader monad.

Computations are functions of a shared environment.

The return function ignores the environment, while >>= passes the inherited environment to both subcomputations.

newtype ReaderT r (m :: Type -> Type) a #

The reader monad transformer, which adds a read-only environment to the given monad.

The return function ignores the environment, while >>= passes the inherited environment to both subcomputations.

Constructors

ReaderT 

Fields

Instances

Instances details
MonadSplit g m => MonadSplit g (ReaderT r m) 
Instance details

Defined in Control.Monad.Random.Class

Methods

getSplit :: ReaderT r m g #

MonadBase b m => MonadBase b (ReaderT r m) 
Instance details

Defined in Control.Monad.Base

Methods

liftBase :: b α -> ReaderT r m α #

MonadTrans (ReaderT r) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

lift :: Monad m => m a -> ReaderT r m a #

MonadInterleave m => MonadInterleave (ReaderT r m) 
Instance details

Defined in Control.Monad.Random.Class

Methods

interleave :: ReaderT r m a -> ReaderT r m a #

MonadRandom m => MonadRandom (ReaderT r m) 
Instance details

Defined in Control.Monad.Random.Class

Methods

getRandomR :: Random a => (a, a) -> ReaderT r m a #

getRandom :: Random a => ReaderT r m a #

getRandomRs :: Random a => (a, a) -> ReaderT r m [a] #

getRandoms :: Random a => ReaderT r m [a] #

MonadFail m => MonadFail (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

fail :: String -> ReaderT r m a #

MonadFix m => MonadFix (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

mfix :: (a -> ReaderT r m a) -> ReaderT r m a #

MonadIO m => MonadIO (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

liftIO :: IO a -> ReaderT r m a #

MonadZip m => MonadZip (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

mzip :: ReaderT r m a -> ReaderT r m b -> ReaderT r m (a, b) #

mzipWith :: (a -> b -> c) -> ReaderT r m a -> ReaderT r m b -> ReaderT r m c #

munzip :: ReaderT r m (a, b) -> (ReaderT r m a, ReaderT r m b) #

Contravariant m => Contravariant (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

contramap :: (a' -> a) -> ReaderT r m a -> ReaderT r m a' #

(>$) :: b -> ReaderT r m b -> ReaderT r m a #

Alternative m => Alternative (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

empty :: ReaderT r m a #

(<|>) :: ReaderT r m a -> ReaderT r m a -> ReaderT r m a #

some :: ReaderT r m a -> ReaderT r m [a] #

many :: ReaderT r m a -> ReaderT r m [a] #

Applicative m => Applicative (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

pure :: a -> ReaderT r m a #

(<*>) :: ReaderT r m (a -> b) -> ReaderT r m a -> ReaderT r m b #

liftA2 :: (a -> b -> c) -> ReaderT r m a -> ReaderT r m b -> ReaderT r m c #

(*>) :: ReaderT r m a -> ReaderT r m b -> ReaderT r m b #

(<*) :: ReaderT r m a -> ReaderT r m b -> ReaderT r m a #

Functor m => Functor (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

fmap :: (a -> b) -> ReaderT r m a -> ReaderT r m b #

(<$) :: a -> ReaderT r m b -> ReaderT r m a #

Monad m => Monad (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

(>>=) :: ReaderT r m a -> (a -> ReaderT r m b) -> ReaderT r m b #

(>>) :: ReaderT r m a -> ReaderT r m b -> ReaderT r m b #

return :: a -> ReaderT r m a #

MonadPlus m => MonadPlus (ReaderT r m) 
Instance details

Defined in Control.Monad.Trans.Reader

Methods

mzero :: ReaderT r m a #

mplus :: ReaderT r m a -> ReaderT r m a -> ReaderT r m a #

reader :: forall (m :: Type -> Type) r a. Monad m => (r -> a) -> ReaderT r m a #

Constructor for computations in the reader monad (equivalent to asks).

local #

Arguments

:: forall r (m :: Type -> Type) a. (r -> r)

The function to modify the environment.

-> ReaderT r m a

Computation to run in the modified environment.

-> ReaderT r m a 

Execute a computation in a modified environment (a specialization of withReaderT).

asks #

Arguments

:: forall (m :: Type -> Type) r a. Monad m 
=> (r -> a)

The selector function to apply to the environment.

-> ReaderT r m a 

Retrieve a function of the current environment.

ask :: forall (m :: Type -> Type) r. Monad m => ReaderT r m r #

Fetch the value of the environment.

Reader MSF running and wrapping.

readerS :: Monad m => MSF m (r, a) b -> MSF (ReaderT r m) a b Source #

Build an MSF in the Reader monad from one that takes the reader environment as an extra input. This is the opposite of runReaderS.

runReaderS :: Monad m => MSF (ReaderT r m) a b -> MSF m (r, a) b Source #

Build an MSF that takes an environment as an extra input from one on the Reader monad. This is the opposite of readerS.

runReaderS_ :: Monad m => MSF (ReaderT s m) a b -> s -> MSF m a b Source #

Build an MSF function that takes a fixed environment as additional input, from an MSF in the Reader monad.