Safe Haskell	None
Language	Haskell2010

Control.Effect.State.Strict

Synopsis

data State s (m :: * -> *) k
- = Get (s -> k)
- | Put s k
get :: (Member (State s) sig, Carrier sig m) => m s
gets :: (Member (State s) sig, Carrier sig m) => (s -> a) -> m a
put :: (Member (State s) sig, Carrier sig m) => s -> m ()
modify :: (Member (State s) sig, Carrier sig m) => (s -> s) -> m ()
modifyLazy :: (Member (State s) sig, Carrier sig m) => (s -> s) -> m ()
newtype StateC s m a = StateC {
- runStateC :: s -> m (s, a)
}
runState :: s -> StateC s m a -> m (s, a)
evalState :: forall s m a. Functor m => s -> StateC s m a -> m a
execState :: forall s m a. Functor m => s -> StateC s m a -> m s

Documentation

data State s (m :: * -> *) k Source #

Constructors

Get (s -> k)
Put s k

Instances

Effect (State s) Source #
Instance details Defined in Control.Effect.State.Internal Methods handle :: Functor f => f () -> (forall x. f (m x) -> n (f x)) -> State s m (m a) -> State s n (n (f a)) Source #
HFunctor (State s) Source #
Instance details Defined in Control.Effect.State.Internal Methods fmap' :: (a -> b) -> State s m a -> State s m b Source # hmap :: (forall x. m x -> n x) -> State s m a -> State s n a Source #
Functor (State s m) Source #
Instance details Defined in Control.Effect.State.Internal Methods fmap :: (a -> b) -> State s m a -> State s m b # (<$) :: a -> State s m b -> State s m a #
(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods eff :: (State s :+: sig) (StateC s m) (StateC s m a) -> StateC s m a Source # ret :: a -> StateC s m a Source #
(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Effect.State.Lazy Methods eff :: (State s :+: sig) (StateC s m) (StateC s m a) -> StateC s m a Source # ret :: a -> StateC s m a Source #

get :: (Member (State s) sig, Carrier sig m) => m s Source #

Get the current state value.

snd (run (runState a get)) == a

gets :: (Member (State s) sig, Carrier sig m) => (s -> a) -> m a Source #

Project a function out of the current state value.

snd (run (runState a (gets (applyFun f)))) == applyFun f a

put :: (Member (State s) sig, Carrier sig m) => s -> m () Source #

Replace the state value with a new value.

fst (run (runState a (put b))) == b

snd (run (runState a (get <* put b))) == a

snd (run (runState a (put b *> get))) == b

modify :: (Member (State s) sig, Carrier sig m) => (s -> s) -> m () Source #

Replace the state value with the result of applying a function to the current state value. This is strict in the new state.

fst (run (runState a (modify (+1)))) == (1 + a :: Integer)

modifyLazy :: (Member (State s) sig, Carrier sig m) => (s -> s) -> m () Source #

Replace the state value with the result of applying a function to the current state value. This is lazy in the new state; injudicious use of this function may lead to space leaks.

newtype StateC s m a Source #

Constructors

StateC
Fields runStateC :: s -> m (s, a)

Instances

MonadTrans (StateC s) Source #
Instance details Defined in Control.Effect.State.Strict Methods lift :: Monad m => m a -> StateC s m a #
Monad m => Monad (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods (>>=) :: StateC s m a -> (a -> StateC s m b) -> StateC s m b # (>>) :: StateC s m a -> StateC s m b -> StateC s m b # return :: a -> StateC s m a # fail :: String -> StateC s m a #
Functor m => Functor (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods fmap :: (a -> b) -> StateC s m a -> StateC s m b # (<$) :: a -> StateC s m b -> StateC s m a #
MonadFail m => MonadFail (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods fail :: String -> StateC s m a #
Monad m => Applicative (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods pure :: a -> StateC s m a # (<>) :: StateC s m (a -> b) -> StateC s m a -> StateC s m b # liftA2 :: (a -> b -> c) -> StateC s m a -> StateC s m b -> StateC s m c # (>) :: StateC s m a -> StateC s m b -> StateC s m b # (<*) :: StateC s m a -> StateC s m b -> StateC s m a #
MonadIO m => MonadIO (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods liftIO :: IO a -> StateC s m a #
(Alternative m, Monad m) => Alternative (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods empty :: StateC s m a # (<\|>) :: StateC s m a -> StateC s m a -> StateC s m a # some :: StateC s m a -> StateC s m [a] # many :: StateC s m a -> StateC s m [a] #
(Alternative m, Monad m) => MonadPlus (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods mzero :: StateC s m a # mplus :: StateC s m a -> StateC s m a -> StateC s m a #
(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods eff :: (State s :+: sig) (StateC s m) (StateC s m a) -> StateC s m a Source # ret :: a -> StateC s m a Source #

runState :: s -> StateC s m a -> m (s, a) Source #

Run a State effect starting from the passed value.

run (runState a (pure b)) == (a, b)

evalState :: forall s m a. Functor m => s -> StateC s m a -> m a Source #

Run a State effect, yielding the result value and discarding the final state.

run (evalState a (pure b)) == b

execState :: forall s m a. Functor m => s -> StateC s m a -> m s Source #

Run a State effect, yielding the final state and discarding the return value.

run (execState a (pure b)) == a