Control.Effect.State.Lazy

State effect

module Control.Effect.State.Internal

Lazy state carrier

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

Run a lazy State effect, yielding the result value and the final state. More programs terminate with lazy state than strict state, but injudicious use of lazy state may lead to thunk buildup.

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

take 5 . snd . run $ runState () (traverse pure [1..]) === [1,2,3,4,5]

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

Run a lazy 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

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

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

newtype StateC s m a

Constructors

StateC

Fields

• runStateC :: s -> m (s, a)

Instances

MonadTrans (StateC s)

Defined in Control.Effect.State.Lazy

Methods

lift :: Monad m => m a -> StateC s m a

Monad m => Monad (StateC s m)

Defined in Control.Effect.State.Lazy

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

Functor m => Functor (StateC s m)

Defined in Control.Effect.State.Lazy

Methods

fmap :: (a -> b) -> StateC s m a -> StateC s m b

(<$) :: a -> StateC s m b -> StateC s m a

MonadFix m => MonadFix (StateC s m)

Defined in Control.Effect.State.Lazy

Methods

mfix :: (a -> StateC s m a) -> StateC s m a

MonadFail m => MonadFail (StateC s m)

Defined in Control.Effect.State.Lazy

Methods

fail :: String -> StateC s m a

(Functor m, Monad m) => Applicative (StateC s m)

Defined in Control.Effect.State.Lazy

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)

Defined in Control.Effect.State.Lazy

Methods

liftIO :: IO a -> StateC s m a

(Alternative m, Monad m) => Alternative (StateC s m)

Defined in Control.Effect.State.Lazy

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)

Defined in Control.Effect.State.Lazy

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)

Defined in Control.Effect.State.Lazy

Methods

eff :: (State s :+: sig) (StateC s m) a -> StateC s m a

Re-exports

class (HFunctor sig, Monad m) => Carrier sig m | m -> sig

The class of carriers (results) for algebras (effect handlers) over signatures (effects), whose actions are given by the eff method.

Minimal complete definition

eff

Instances

Carrier Pure PureC

Defined in Control.Effect.Carrier

Methods

eff :: Pure PureC a -> PureC a

(HFunctor eff, Carrier sig m, Member eff sig) => Carrier sig (InterposeC eff m)

Defined in Control.Effect.Interpose

Methods

eff :: sig (InterposeC eff m) a -> InterposeC eff m a

Monad m => Carrier (Lift m) (LiftC m)

Defined in Control.Effect.Lift

Methods

eff :: Lift m (LiftC m) a -> LiftC m a

(Carrier sig m, MonadIO m) => Carrier (Resource :+: sig) (ResourceC m)

Defined in Control.Effect.Resource

Methods

eff :: (Resource :+: sig) (ResourceC m) a -> ResourceC m a

(Carrier sig m, Effect sig) => Carrier (NonDet :+: sig) (NonDetC m)

Defined in Control.Effect.NonDet

Methods

eff :: (NonDet :+: sig) (NonDetC m) a -> NonDetC m a

(Carrier sig m, Effect sig) => Carrier (NonDet :+: sig) (OnceC m)

Defined in Control.Effect.Cull

Methods

eff :: (NonDet :+: sig) (OnceC m) a -> OnceC m a

(Carrier sig m, Effect sig) => Carrier (Fresh :+: sig) (FreshC m)

Defined in Control.Effect.Fresh

Methods

eff :: (Fresh :+: sig) (FreshC m) a -> FreshC m a

(Carrier sig m, Effect sig) => Carrier (Fail :+: sig) (FailC m)

Defined in Control.Effect.Fail

Methods

eff :: (Fail :+: sig) (FailC m) a -> FailC m a

(Carrier sig m, Effect sig) => Carrier (Cut :+: (NonDet :+: sig)) (CutC m)

Defined in Control.Effect.Cut

Methods

eff :: (Cut :+: (NonDet :+: sig)) (CutC m) a -> CutC m a

(Carrier sig m, Effect sig) => Carrier (Cull :+: (NonDet :+: sig)) (CullC m)

Defined in Control.Effect.Cull

Methods

eff :: (Cull :+: (NonDet :+: sig)) (CullC m) a -> CullC m a

(Carrier sig m, Effect sig) => Carrier (Trace :+: sig) (TraceByReturningC m)

Defined in Control.Effect.Trace

Methods

eff :: (Trace :+: sig) (TraceByReturningC m) a -> TraceByReturningC m a

Carrier sig m => Carrier (Trace :+: sig) (TraceByIgnoringC m)

Defined in Control.Effect.Trace

Methods

eff :: (Trace :+: sig) (TraceByIgnoringC m) a -> TraceByIgnoringC m a

(MonadIO m, Carrier sig m) => Carrier (Trace :+: sig) (TraceByPrintingC m)

Defined in Control.Effect.Trace

Methods

eff :: (Trace :+: sig) (TraceByPrintingC m) a -> TraceByPrintingC m a

(HFunctor eff, Carrier sig m) => Carrier (eff :+: sig) (InterpretC eff m)

Defined in Control.Effect.Interpret

Methods

eff :: (eff :+: sig) (InterpretC eff m) a -> InterpretC eff m a

(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m)

Defined in Control.Effect.State.Strict

Methods

eff :: (State s :+: sig) (StateC s m) a -> StateC s m a

(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m)

Defined in Control.Effect.State.Lazy

Methods

eff :: (State s :+: sig) (StateC s m) a -> StateC s m a

Carrier sig m => Carrier (Reader r :+: sig) (ReaderC r m)

Defined in Control.Effect.Reader

Methods

eff :: (Reader r :+: sig) (ReaderC r m) a -> ReaderC r m a

(Carrier sig m, Effect sig, RandomGen g) => Carrier (Random :+: sig) (RandomC g m)

Defined in Control.Effect.Random

Methods

eff :: (Random :+: sig) (RandomC g m) a -> RandomC g m a

(Carrier sig m, Effect sig) => Carrier (Error e :+: sig) (ErrorC e m)

Defined in Control.Effect.Error

Methods

eff :: (Error e :+: sig) (ErrorC e m) a -> ErrorC e m a

Carrier sig m => Carrier (Resumable err :+: sig) (ResumableWithC err m)

Defined in Control.Effect.Resumable

Methods

eff :: (Resumable err :+: sig) (ResumableWithC err m) a -> ResumableWithC err m a

(Carrier sig m, Effect sig) => Carrier (Resumable err :+: sig) (ResumableC err m)

Defined in Control.Effect.Resumable

Methods

eff :: (Resumable err :+: sig) (ResumableC err m) a -> ResumableC err m a

(Monoid w, Carrier sig m, Effect sig) => Carrier (Writer w :+: sig) (WriterC w m)

Defined in Control.Effect.Writer

Methods

eff :: (Writer w :+: sig) (WriterC w m) a -> WriterC w m a

(HFunctor eff, Carrier sig m, Effect sig) => Carrier (eff :+: sig) (InterpretStateC eff s m)

Defined in Control.Effect.Interpret

Methods

eff :: (eff :+: sig) (InterpretStateC eff s m) a -> InterpretStateC eff s m a

run :: PureC a -> a

Run an action exhausted of effects to produce its final result value.