State.hs

{-# LANGUAGE RankNTypes #-}

newtype State s a = State { runState :: forall r. s -> (a -> s -> r) -> r }

stateReturn :: a -> State s a
stateReturn = undefined

stateMap :: (a -> b) -> State s a -> State s b
stateMap = undefined

stateBind :: (a -> State s b) -> State s a -> State s b
stateBind = undefined

stateGet :: State s s
stateGet = undefined

statePut :: s -> State s ()
statePut = undefined

stateModify  :: (s -> s) -> State s ()
stateModify = undefined

execState :: s -> State s a -> s
execState = undefined

evalState :: s -> State s a -> a
evalState = undefined