writer-cps-monads-tf-0.1.0.1: MonadWriter orphan instances for writer-cps-transformers

Copyright(c) Daniel Mendler 2016
(c) Andy Gill 2001
(c) Oregon Graduate Institute of Science and Technology 2001
LicenseBSD-style (see the file LICENSE)
Maintainermail@daniel-mendler.de
Stabilityexperimental
Portabilitynon-portable (type families)
Safe HaskellSafe
LanguageHaskell2010

Control.Monad.RWS.CPS

Contents

Description

Stricter RWS monad using continuation-passing-style for the writer output.

Inspired by the paper Functional Programming with Overloading and Higher-Order Polymorphism, Mark P Jones (http://web.cecs.pdx.edu/~mpj/) Advanced School of Functional Programming, 1995.

Synopsis

The RWS monad

type RWS r w s = RWST r w s Identity #

A monad containing an environment of type r, output of type w and an updatable state of type s.

rws :: Monoid w => (r -> s -> (a, s, w)) -> RWS r w s a #

Construct an RWS computation from a function. (The inverse of runRWS.)

runRWS :: Monoid w => RWS r w s a -> r -> s -> (a, s, w) #

Unwrap an RWS computation as a function. (The inverse of rws.)

evalRWS #

Arguments

:: Monoid w 
=> RWS r w s a

RWS computation to execute

-> r

initial environment

-> s

initial value

-> (a, w)

final value and output

Evaluate a computation with the given initial state and environment, returning the final value and output, discarding the final state.

execRWS #

Arguments

:: Monoid w 
=> RWS r w s a

RWS computation to execute

-> r

initial environment

-> s

initial value

-> (s, w)

final state and output

Evaluate a computation with the given initial state and environment, returning the final state and output, discarding the final value.

mapRWS :: (Monoid w, Monoid w') => ((a, s, w) -> (b, s, w')) -> RWS r w s a -> RWS r w' s b #

Map the return value, final state and output of a computation using the given function.

withRWS :: (r' -> s -> (r, s)) -> RWS r w s a -> RWS r' w s a #

withRWS f m executes action m with an initial environment and state modified by applying f.

The RWST monad transformer

data RWST r w s m a :: * -> * -> * -> (* -> *) -> * -> * #

A monad transformer adding reading an environment of type r, collecting an output of type w and updating a state of type s to an inner monad m.

Instances

MonadTrans (RWST r w s) 

Methods

lift :: Monad m => m a -> RWST r w s m a #

Monad m => Monad (RWST r w s m) 

Methods

(>>=) :: RWST r w s m a -> (a -> RWST r w s m b) -> RWST r w s m b #

(>>) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m b #

return :: a -> RWST r w s m a #

fail :: String -> RWST r w s m a #

Functor m => Functor (RWST r w s m) 

Methods

fmap :: (a -> b) -> RWST r w s m a -> RWST r w s m b #

(<$) :: a -> RWST r w s m b -> RWST r w s m a #

MonadFix m => MonadFix (RWST r w s m) 

Methods

mfix :: (a -> RWST r w s m a) -> RWST r w s m a #

MonadFail m => MonadFail (RWST r w s m) 

Methods

fail :: String -> RWST r w s m a #

(Functor m, Monad m) => Applicative (RWST r w s m) 

Methods

pure :: a -> RWST r w s m a #

(<*>) :: RWST r w s m (a -> b) -> RWST r w s m a -> RWST r w s m b #

(*>) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m b #

(<*) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m a #

MonadIO m => MonadIO (RWST r w s m) 

Methods

liftIO :: IO a -> RWST r w s m a #

(Functor m, MonadPlus m) => Alternative (RWST r w s m) 

Methods

empty :: RWST r w s m a #

(<|>) :: RWST r w s m a -> RWST r w s m a -> RWST r w s m a #

some :: RWST r w s m a -> RWST r w s m [a] #

many :: RWST r w s m a -> RWST r w s m [a] #

(Functor m, MonadPlus m) => MonadPlus (RWST r w s m) 

Methods

mzero :: RWST r w s m a #

mplus :: RWST r w s m a -> RWST r w s m a -> RWST r w s m a #

type EnvType (RWST r w s m) # 
type EnvType (RWST r w s m) = r
type StateType (RWST r w s m) # 
type StateType (RWST r w s m) = s
type WriterType (RWST r w s m) # 
type WriterType (RWST r w s m) = w

rwsT :: (Functor m, Monoid w) => (r -> s -> m (a, s, w)) -> RWST r w s m a #

runRWST :: Monoid w => RWST r w s m a -> r -> s -> m (a, s, w) #

Unwrap an RWST computation as a function.

evalRWST #

Arguments

:: (Monad m, Monoid w) 
=> RWST r w s m a

computation to execute

-> r

initial environment

-> s

initial value

-> m (a, w)

computation yielding final value and output

Evaluate a computation with the given initial state and environment, returning the final value and output, discarding the final state.

execRWST #

Arguments

:: (Monad m, Monoid w) 
=> RWST r w s m a

computation to execute

-> r

initial environment

-> s

initial value

-> m (s, w)

computation yielding final state and output

Evaluate a computation with the given initial state and environment, returning the final state and output, discarding the final value.

mapRWST :: (Monad n, Monoid w, Monoid w') => (m (a, s, w) -> n (b, s, w')) -> RWST r w s m a -> RWST r w' s n b #

Map the inner computation using the given function.

  • runRWST (mapRWST f m) r s = f (runRWST m r s) mapRWST :: (m (a, s, w) -> n (b, s, w')) -> RWST r w s m a -> RWST r w' s n b

withRWST :: (r' -> s -> (r, s)) -> RWST r w s m a -> RWST r' w s m a #

withRWST f m executes action m with an initial environment and state modified by applying f.

Strict Reader-writer-state monads

Orphan instances

Monad m => MonadReader (RWST r w s m) Source # 

Associated Types

type EnvType (RWST r w s m :: * -> *) :: * #

Methods

ask :: RWST r w s m (EnvType (RWST r w s m)) #

local :: (EnvType (RWST r w s m) -> EnvType (RWST r w s m)) -> RWST r w s m a -> RWST r w s m a #

Monad m => MonadState (RWST r w s m) Source # 

Associated Types

type StateType (RWST r w s m :: * -> *) :: * #

Methods

get :: RWST r w s m (StateType (RWST r w s m)) #

put :: StateType (RWST r w s m) -> RWST r w s m () #

(Monoid w, Monad m) => MonadWriter (RWST r w s m) Source # 

Associated Types

type WriterType (RWST r w s m :: * -> *) :: * #

Methods

tell :: WriterType (RWST r w s m) -> RWST r w s m () #

listen :: RWST r w s m a -> RWST r w s m (a, WriterType (RWST r w s m)) #

pass :: RWST r w s m (a, WriterType (RWST r w s m) -> WriterType (RWST r w s m)) -> RWST r w s m a #