Algebra.Monad.State

The State Monad

class Monad m => MonadState s m | m -> s where

Methods

get :: m s

put :: s -> m ()

modify :: (s -> s) -> m ()

Instances

MonadState s m => MonadState s (ListT m)

Monad m => MonadState s (StateT s m)

MonadState s m => MonadState s (ReaderT r m)

(Monoid w, MonadState r m) => MonadState r (WriterT w m)

(MonadState s m, Monoid w, SubSemi acc w) => MonadState s (WriterAccT w acc m)

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

MonadState (IO ()) IO

data StateT s m a

Instances

MonadWriterAcc w acc m => MonadWriterAcc w acc (StateT s m)

(Monad m, MonadFuture n m) => MonadFuture n (StateT s m)

MonadError e m => MonadError e (StateT s m)

MonadWriter w m => MonadWriter w (StateT s m)

MonadReader r m => MonadReader r (StateT s m)

Monad m => MonadState s (StateT s m)

MonadTrans (StateT s)

MonadInternal (StateT s)

Unit m => Unit (StateT s m)

MonadCont m => MonadCont (StateT s m)

MonadList m => MonadList (StateT s m)

MonadFix m => MonadFix (StateT s m)

Monad m => Monad (StateT s m)

Monad m => Applicative (StateT s m)

Functor m => Functor (StateT s m)

Ring (m (a, s, Void)) => Ring (StateT s m a)

Semiring (m (a, s, Void)) => Semiring (StateT s m a)

Monoid (m (a, s, Void)) => Monoid (StateT s m a)

Semigroup (m (a, s, Void)) => Semigroup (StateT s m a)

type State s a = StateT s Id a

stateT :: (Functor m, Functor n) => Iso (StateT s m a) (StateT t n b) (s -> m (s, a)) (t -> n (t, b))

eval :: (s -> (a, b)) -> s -> b

exec :: Functor f => f (a, b) -> f a

state :: Iso (State s a) (State t b) (s -> (s, a)) (t -> (t, b))

(=~) :: MonadState s m => Traversal' s a -> (a -> a) -> m ()

(=-) :: MonadState s m => Traversal' s s' -> s' -> m ()

(^>=) :: MonadState s m => LensLike m a a s s -> (a -> m ()) -> m ()

gets :: MonadState s m => (s -> a) -> m a

getl :: MonadState s m => Getter' s a -> m a

saving :: MonadState s m => Lens' s s' -> m a -> m a

type Next a = a

type Prev a = a

mapAccum :: Traversable t => (a -> s -> (s, b)) -> t a -> s -> (s, t b)

mapAccum_ :: Traversable t => (a -> s -> (s, b)) -> t a -> s -> t b

mapAccumR :: Traversable t => (a -> s -> (s, b)) -> t a -> s -> (s, t b)

mapAccumR_ :: Traversable t => (a -> s -> (s, b)) -> t a -> s -> t b

push :: Traversable t => t a -> a -> t a

pop :: Traversable t => t a -> a -> t a

withPrev :: Traversable t => a -> t a -> t (Prev a, a)

withNext :: Traversable t => t a -> a -> t (a, Next a)

The State Arrow

newtype StateA m s a

Constructors

StateA (StateT s m a)

Instances

Monad m => Split (StateA m)

Monad m => Choice (StateA m)

Monad m => Category (StateA m)

Monad m => Arrow (StateA m)

stateA :: Iso (StateA m s a) (StateA m' s' a') (StateT s m a) (StateT s' m' a')