Moduleeffectful-core-2.7.1.2GHC2021

Effectful.Labeled.Input

Convenience functions for the Labeled Input effect.

Effect

1 declaration

datadata Input i (a :: Type -> Type) b where

Provide access to values of type i.

Instances1DispatchOf

type DispatchOf (Input i) = 'DynamicDefined in effectful-core-2.7.1.2 · Effectful.Input.Dynamic

valuerunInput

Run the Input effect with the given value.

valuerunInputAction

Run the Input effect with the given action that supplies values.

valueinput :: (HasCallStack, Labeled label (Input i) :> es) => Eff es i

Fetch the value.

valueinputs

Fetch the result of applying a function to the value.

inputs f ≡ f <$> input

1 declaration

newtypenewtype Labeled (label :: k) (e :: Effect) (a :: Type -> Type) b where

Assign a label to an effect.

Note: labeled effects are best used together with the effectful-plugin package, as it significantly improves their usability.

The constructor is for sending labeled operations of a dynamically dispatched effect to the handler:

Example1 expression

>>> import Effectful.Dispatch.Dynamic

Example1 expression

>>> :{  data X :: Effect where    X :: X m Int  type instance DispatchOf X = Dynamic:}

Example1 expression

>>> :{  runPureEff . runLabeled @"x" (interpret_ $ \X -> pure 333) $ do    send $ Labeled @"x" X:}333

Instances2DispatchOf, StaticRep

type DispatchOf (Labeled label e) = DispatchOf eDefined in effectful-core-2.7.1.2 · Effectful.Labeled
data StaticRep (Labeled label e)Defined in effectful-core-2.7.1.2 · Effectful.Labeled