Control.Proxy.Trans.State

This module provides the proxy transformer equivalent of StateT.

Sequencing of computations is strict.

StateP

newtype StateP s p a' a b' b m r

The strict State proxy transformer

Constructors

StateP

Fields

• unStateP :: s -> p a' a b' b m (r, s)

Instances

ProxyTrans (StateP s)

Methods

liftP :: (Monad (p b c d e m), Channel p) => p b c d e m r -> StateP s p b c d e m r

mapP :: (Monad (p b c d e m), Channel p) => (a -> p b c d e m r) -> a -> StateP s p b c d e m r

Channel p => Channel (StateP s p)

Methods

idT :: Monad m => a' -> StateP s p a' a a' a m r

(>->) :: Monad m => (b' -> StateP s p a' a b' b m r) -> (c' -> StateP s p b' b c' c m r) -> c' -> StateP s p a' a c' c m r

(<-<) :: Monad m => (c' -> StateP s p b' b c' c m r) -> (b' -> StateP s p a' a b' b m r) -> c' -> StateP s p a' a c' c m r

MonadTrans (p a' a b' b) => MonadTrans (StateP s p a' a b' b)

Methods

lift :: Monad m => m a -> StateP s p a' a b' b m a

MFunctor (p a' a b' b) => MFunctor (StateP s p a' a b' b)

Methods

mapT :: (Monad m, Monad n) => (forall c. m c -> n c) -> StateP s p a' a b' b m b -> StateP s p a' a b' b n b

Monad (p a' a b' b m) => Monad (StateP s p a' a b' b m)

Methods

(>>=) :: StateP s p a' a b' b m a -> (a -> StateP s p a' a b' b m b) -> StateP s p a' a b' b m b

(>>) :: StateP s p a' a b' b m a -> StateP s p a' a b' b m b -> StateP s p a' a b' b m b

return :: a -> StateP s p a' a b' b m a

fail :: String -> StateP s p a' a b' b m a

Monad (p a' a b' b m) => Functor (StateP s p a' a b' b m)

Methods

fmap :: (a -> b) -> StateP s p a' a b' b m a -> StateP s p a' a b' b m b

(<$) :: a -> StateP s p a' a b' b m b -> StateP s p a' a b' b m a

Monad (p a' a b' b m) => Applicative (StateP s p a' a b' b m)

Methods

pure :: a -> StateP s p a' a b' b m a

(<*>) :: StateP s p a' a b' b m (a -> b) -> StateP s p a' a b' b m a -> StateP s p a' a b' b m b

(*>) :: StateP s p a' a b' b m a -> StateP s p a' a b' b m b -> StateP s p a' a b' b m b

(<*) :: StateP s p a' a b' b m a -> StateP s p a' a b' b m b -> StateP s p a' a b' b m a

MonadIO (p a' a b' b m) => MonadIO (StateP s p a' a b' b m)

Methods

liftIO :: IO a -> StateP s p a' a b' b m a

MonadPlus (p a' a b' b m) => Alternative (StateP s p a' a b' b m)

Methods

empty :: StateP s p a' a b' b m a

(<|>) :: StateP s p a' a b' b m a -> StateP s p a' a b' b m a -> StateP s p a' a b' b m a

some :: StateP s p a' a b' b m a -> StateP s p a' a b' b m [a]

many :: StateP s p a' a b' b m a -> StateP s p a' a b' b m [a]

MonadPlus (p a' a b' b m) => MonadPlus (StateP s p a' a b' b m)

Methods

mzero :: StateP s p a' a b' b m a

mplus :: StateP s p a' a b' b m a -> StateP s p a' a b' b m a -> StateP s p a' a b' b m a

runStateP :: s -> StateP s p a' a b' b m r -> p a' a b' b m (r, s)

Run a StateP computation, producing the final result and state

runStateK :: s -> (q -> StateP s p a' a b' b m r) -> q -> p a' a b' b m (r, s)

Run a StateP 'K'leisli arrow, procuding the final result and state

evalStateP :: Monad (p a' a b' b m) => s -> StateP s p a' a b' b m r -> p a' a b' b m r

Evaluate a StateP computation, but discard the final state

evalStateK :: Monad (p a' a b' b m) => s -> (q -> StateP s p a' a b' b m r) -> q -> p a' a b' b m r

Evaluate a StateP 'K'leisli arrow, but discard the final state

execStateP :: Monad (p a' a b' b m) => s -> StateP s p a' a b' b m r -> p a' a b' b m s

Evaluate a StateP computation, but discard the final result

execStateK :: Monad (p a' a b' b m) => s -> (q -> StateP s p a' a b' b m r) -> q -> p a' a b' b m s

Evaluate a StateP 'K'leisli arrow, but discard the final result

State operations

get :: Monad (p a' a b' b m) => StateP s p a' a b' b m s

Get the current state

put :: Monad (p a' a b' b m) => s -> StateP s p a' a b' b m ()

Set the current state

modify :: Monad (p a' a b' b m) => (s -> s) -> StateP s p a' a b' b m ()

Modify the current state using a function

gets :: Monad (p a' a b' b m) => (s -> r) -> StateP s p a' a b' b m r

Get the state filtered through a function