src/Reflex/PostBuild/Class.hs · reflex

on ae@dev-script help sign in

41 lines 1.5 kB history raw

1-- | This module defines 'PostBuild', which indicates that an action will be

2-- notified when it, and any action it's a part of, has finished executing.

3{-# LANGUAGE CPP #-}

4{-# LANGUAGE DataKinds #-}

5{-# LANGUAGE FlexibleInstances #-}

6{-# LANGUAGE FunctionalDependencies #-}

7{-# LANGUAGE ScopedTypeVariables #-}

8{-# LANGUAGE TypeFamilies #-}

9{-# LANGUAGE TypeOperators #-}

10{-# LANGUAGE UndecidableInstances #-}

11#ifdef USE_REFLEX_OPTIMIZER

12{-# OPTIONS_GHC -fplugin=Reflex.Optimizer #-}

13#endif

14module Reflex.PostBuild.Class

15 ( PostBuild (..)

16 ) where

18import Reflex.Class

20import Control.Monad.Reader

21import Control.Monad.State

22import qualified Control.Monad.State.Strict as Strict

24-- | 'PostBuild' represents an action that is notified via an 'Event' when it

25-- has finished executing. Note that the specific definition of "finished" is

26-- determined by the instance of 'PostBuild', but the intent is to allow

27-- 'Behavior's and 'Dynamic's to be safely sampled, regardless of where they

28-- were created, when the post-build 'Event' fires. The post-build 'Event' will

29-- fire exactly once for an given action.

30class (Reflex t, Monad m) => PostBuild t m | m -> t where

31 -- | Retrieve the post-build 'Event' for this action.

32 getPostBuild :: m (Event t ())

34instance PostBuild t m => PostBuild t (ReaderT r m) where

35 getPostBuild = lift getPostBuild

37instance PostBuild t m => PostBuild t (StateT s m) where

38 getPostBuild = lift getPostBuild

40instance PostBuild t m => PostBuild t (Strict.StateT s m) where

41 getPostBuild = lift getPostBuild