Control.Monad.Trans.RevState

Monad Transformer

newtype StateT s m a

Constructors

StateT

Fields

runStateT :: s -> m (a, s)

Instances

MonadFix m => MonadRevState s (StateT s m)

MonadFix m => Monad (StateT s m)

Monad m => Functor (StateT s m)

MonadFix m => MonadFix (StateT s m)

MonadFix m => Applicative (StateT s m)

evalStateT :: Monad m => StateT s m a -> s -> m a

execStateT :: Monad m => StateT s m a -> s -> m s

mapStateT :: (m (a, s) -> n (b, s)) -> StateT s m a -> StateT s n b

withStateT :: (s -> s) -> StateT s m a -> StateT s m a

Monad

type State s = StateT s Identity

runState :: State s a -> s -> (a, s)

evalState :: State s a -> s -> a

execState :: State s a -> s -> s

mapState :: ((a, s) -> (b, s)) -> State s a -> State s b

withState :: (s -> s) -> State s a -> State s a

Primitives and basic combinators

get :: Monad m => StateT s m s

put :: Monad m => s -> StateT s m ()

state :: Monad m => (s -> (a, s)) -> StateT s m a

gets :: Monad m => (s -> a) -> StateT s m a

modify :: Monad m => (s -> s) -> StateT s m ()