Safe Haskell	None
Language	Haskell2010

Effectful.State.Dynamic

Contents

Effect
- Handlers
  - Local
  - Shared
- Operations

Description

The dynamically dispatched variant of the State effect.

Note: unless you plan to change interpretations at runtime or you need the MonadState instance for compatibility with existing code, it's recommended to use one of the statically dispatched variants, i.e. Effectful.State.Static.Local or Effectful.State.Static.Shared.

Synopsis

data State s (a :: Type -> Type) b where
- Get :: forall s (a :: Type -> Type). State s a s
- Put :: forall s (a :: Type -> Type). s -> State s a ()
- State :: forall s b (a :: Type -> Type). (s -> (b, s)) -> State s a b
- StateM :: forall s (a :: Type -> Type) b. (s -> a (b, s)) -> State s a b
runStateLocal :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es (a, s)
evalStateLocal :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es a
execStateLocal :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es s
runStateShared :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es (a, s)
evalStateShared :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es a
execStateShared :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es s
get :: forall s (es :: [Effect]). (HasCallStack, State s :> es) => Eff es s
gets :: forall s (es :: [Effect]) a. (HasCallStack, State s :> es) => (s -> a) -> Eff es a
put :: forall s (es :: [Effect]). (HasCallStack, State s :> es) => s -> Eff es ()
state :: forall s (es :: [Effect]) a. (HasCallStack, State s :> es) => (s -> (a, s)) -> Eff es a
modify :: forall s (es :: [Effect]). (HasCallStack, State s :> es) => (s -> s) -> Eff es ()
stateM :: forall s (es :: [Effect]) a. (HasCallStack, State s :> es) => (s -> Eff es (a, s)) -> Eff es a
modifyM :: forall s (es :: [Effect]). (HasCallStack, State s :> es) => (s -> Eff es s) -> Eff es ()

Effect

data State s (a :: Type -> Type) b where Source #

Provide access to a mutable value of type s.

Constructors

Get :: forall s (a :: Type -> Type). State s a s
Put :: forall s (a :: Type -> Type). s -> State s a ()
State :: forall s b (a :: Type -> Type). (s -> (b, s)) -> State s a b
StateM :: forall s (a :: Type -> Type) b. (s -> a (b, s)) -> State s a b

Instances

Instances details

type DispatchOf (State s) Source #
Instance details Defined in Effectful.Internal.MTL type DispatchOf (State s) = 'Dynamic

Handlers

Local

runStateLocal :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es (a, s) Source #

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 :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es a Source #

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

execStateLocal :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es s Source #

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 :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es (a, s) Source #

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 :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es a Source #

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

execStateShared :: forall s (es :: [(Type -> Type) -> Type -> Type]) a. HasCallStack => s -> Eff (State s ': es) a -> Eff es s Source #

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 s (es :: [Effect]). (HasCallStack, State s :> es) => Eff es s Source #

Fetch the current value of the state.

gets :: forall s (es :: [Effect]) a. (HasCallStack, State s :> es) => (s -> a) -> Eff es a Source #

Get a function of the current state.

gets f ≡ f <$> get

put :: forall s (es :: [Effect]). (HasCallStack, State s :> es) => s -> Eff es () Source #

Set the current state to the given value.

state :: forall s (es :: [Effect]) a. (HasCallStack, State s :> es) => (s -> (a, s)) -> Eff es a Source #

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

modify :: forall s (es :: [Effect]). (HasCallStack, State s :> es) => (s -> s) -> Eff es () Source #

Apply the function to the current state.

modify f ≡ state (\s -> ((), f s))

stateM :: forall s (es :: [Effect]) a. (HasCallStack, State s :> es) => (s -> Eff es (a, s)) -> Eff es a Source #

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

modifyM :: forall s (es :: [Effect]). (HasCallStack, State s :> es) => (s -> Eff es s) -> Eff es () Source #

Apply the monadic function to the current state.

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