Safe Haskell | Safe |
---|---|
Language | Haskell2010 |
- type RWS r w s = RWST r w s Identity
- rws :: Monoid w => (r -> s -> (a, s, w)) -> RWS r w s a
- runRWS :: Monoid w => RWS r w s a -> r -> s -> (a, s, w)
- evalRWS :: Monoid w => RWS r w s a -> r -> s -> (a, w)
- execRWS :: Monoid w => RWS r w s a -> r -> s -> (s, w)
- mapRWS :: (Monoid w, Monoid w') => ((a, s, w) -> (b, s, w')) -> RWS r w s a -> RWS r w' s b
- withRWS :: (r' -> s -> (r, s)) -> RWS r w s a -> RWS r' w s a
- data RWST r w s m a :: * -> * -> * -> (* -> *) -> * -> *
- runRWST :: Monoid w => RWST r w s m a -> r -> s -> m (a, s, w)
- evalRWST :: (Functor m, Monoid w) => RWST r w s m a -> r -> s -> m (a, w)
- execRWST :: (Functor m, Monoid w) => RWST r w s m a -> r -> s -> m (s, w)
- mapRWST :: (Functor 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
- withRWST :: (r' -> s -> (r, s)) -> RWST r w s m a -> RWST r' w s m a
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
.)
:: 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.
:: 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.
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
.
MonadTrans (RWST r w s) | |
Monad m => Monad (RWST r w s m) | |
Functor m => Functor (RWST r w s m) | |
MonadFix m => MonadFix (RWST r w s m) | |
MonadFail m => MonadFail (RWST r w s m) | |
(Functor m, Monad m) => Applicative (RWST r w s m) | |
MonadIO m => MonadIO (RWST r w s m) | |
(Functor m, MonadPlus m) => Alternative (RWST r w s m) | |
(Functor m, MonadPlus m) => MonadPlus (RWST r w s m) | |
runRWST :: Monoid w => RWST r w s m a -> r -> s -> m (a, s, w) #
Unwrap an RWST computation as a function.
:: (Functor 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.
:: (Functor 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 :: (Functor 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 #