Modulepolysemy-1.9.2.0Haskell2010

Polysemy.Async

Effect

1 declaration

datadata Async (m :: Type -> Type) a where

An effect for spawning asynchronous computations.

The Maybe returned by async is due to the fact that we can't be sure an Error effect didn't fail locally.

Async :: m a -> Async m ano verb
Run the given action asynchronously and return a thread handle.
Await :: Async a -> Async m aawait
Wait for the thread referenced by the given handle to terminate.
Cancel :: Async a -> Async m ano verb
Cancel the thread referenced by the given handle.

3 declarations

valueasync :: Member Async r => Sem r a -> Sem r (Async (Maybe a))

Run the given action asynchronously and return a thread handle.

valueawait :: Member Async r => Async a -> Sem r a

Wait for the thread referenced by the given handle to terminate.

valuecancel :: Member Async r => Async a -> Sem r ()

Cancel the thread referenced by the given handle.

1 declaration

valuesequenceConcurrently

Perform a sequence of effectful actions concurrently.

1 declaration

valueasyncToIOFinal :: Member (Final IO) r => Sem (Async ': r) a -> Sem r a

Run an Async effect in terms of async through final IO.

Beware: Effects that aren't interpreted in terms of IO will have local state semantics in regards to Async effects interpreted this way. See Final.