Effectful.Labeled.State

Convenience functions for the Labeled State effect.

Since: 2.4.0.0

Effect

data State s :: Effect where

Provide access to a mutable value of type s.

Constructors

Get :: State s m s

Put :: s -> State s m ()

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

StateM :: (s -> m (a, s)) -> State s m a

Instances

type DispatchOf (State s)

Defined in Effectful.State.Dynamic

type DispatchOf (State s) = 'Dynamic

Handlers

Local

runStateLocal

Arguments

:: forall label s es a. HasCallStack

=> s

The initial state.

-> Eff (Labeled label (State s) : es) a

-> Eff es (a, s)

Run the State effect with the given initial state and return the final value along with the final state (via Effectful.State.Static.Local).

evalStateLocal

Arguments

:: forall label s es a. HasCallStack

=> s

The initial state.

-> Eff (Labeled label (State s) : es) a

-> Eff es a

Run the State effect with the given initial state and return the final value, discarding the final state (via Effectful.State.Static.Local).

execStateLocal

Arguments

:: forall label s es a. HasCallStack

=> s

The initial state.

-> Eff (Labeled label (State s) : es) a

-> Eff es s

Run the State effect with the given initial state and return the final state, discarding the final value (via Effectful.State.Static.Local).

Shared

runStateShared

Arguments

:: forall label s es a. HasCallStack

=> s

The initial state.

-> Eff (Labeled label (State s) : es) a

-> Eff es (a, s)

Run the State effect with the given initial state and return the final value along with the final state (via Effectful.State.Static.Shared).

evalStateShared

Arguments

:: forall label s es a. HasCallStack

=> s

The initial state.

-> Eff (Labeled label (State s) : es) a

-> Eff es a

Run the State effect with the given initial state and return the final value, discarding the final state (via Effectful.State.Static.Shared).

execStateShared

Arguments

:: forall label s es a. HasCallStack

=> s

The initial state.

-> Eff (Labeled label (State s) : es) a

-> Eff es s

Run the State effect with the given initial state and return the final state, discarding the final value (via Effectful.State.Static.Shared).

Operations

get :: forall label s es. (HasCallStack, Labeled label (State s) :> es) => Eff es s

Fetch the current value of the state.

gets

Arguments

:: forall label s es a. (HasCallStack, Labeled label (State s) :> es)

=> (s -> a)

.

-> Eff es a

Get a function of the current state.

gets f ≡ f <$> get

put

Arguments

:: forall label s es. (HasCallStack, Labeled label (State s) :> es)

=> s

.

-> Eff es ()

Set the current state to the given value.

state

Arguments

:: forall label s es a. (HasCallStack, Labeled label (State s) :> es)

=> (s -> (a, s))

.

-> Eff es a

Apply the function to the current state and return a value.

modify

Arguments

:: forall label s es. (HasCallStack, Labeled label (State s) :> es)

=> (s -> s)

.

-> Eff es ()

Apply the function to the current state.

modify f ≡ state (\s -> ((), f s))

stateM

Arguments

:: forall label s es a. (HasCallStack, Labeled label (State s) :> es)

=> (s -> Eff es (a, s))

.

-> Eff es a

Apply the monadic function to the current state and return a value.

modifyM

Arguments

:: forall label s es. (HasCallStack, Labeled label (State s) :> es)

=> (s -> Eff es s)

.

-> Eff es ()

Apply the monadic function to the current state.

modifyM f ≡ stateM (\s -> ((), ) <$> f s)