Moduleeffectful-core-2.7.1.2GHC2021

Effectful.Labeled.Provider

Convenience functions for the Labeled Provider effect.

Effect

2 declarations

datadata Provider (e :: Effect) input (f :: Type -> Type) (a :: Type -> Type) b where

Provide a way to run a handler of e with a given input.

Note: f can be used to alter the return type of the effect handler. If that's unnecessary, use Provider_.

ProvideWith :: input -> Eff (e ': es) a -> Provider e input f a (f a)
Run the effect handler with a given input.

Instances1DispatchOf

type DispatchOf (Provider e input f) = 'DynamicDefined in effectful-core-2.7.1.2 · Effectful.Provider

typetype Provider_ (e :: Effect) input = Provider e input Identity

A restricted variant of Provider with unchanged return type of the effect handler.

valuerunProvider

:: HasCallStack
=> (forall r. HasCallStack => input -> Eff (e ': es) r -> Eff es (f r))
The effect handler.
-> Eff (Labeled label (Provider e input f) ': es) a
-> Eff es a

Run the labeled Provider effect with a given effect handler.

valuerunProvider_

:: HasCallStack
=> (forall r. HasCallStack => input -> Eff (e ': es) r -> Eff es r)
The effect handler.
-> Eff (Labeled label (Provider_ e input) ': es) a
-> Eff es a

Run the labeled Provider effect with a given effect handler that doesn't change its return type.

valueprovide

Run the effect handler.

valueprovide_

Run the effect handler with unchanged return type.

valueprovideWith

Run the effect handler with a given input.

valueprovideWith_

Run the effect handler that doesn't change its return type with a given 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