src/Reflex/PostBuild/Class.hs · patch

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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 MultiParamTypeClasses #-}

8{-# LANGUAGE ScopedTypeVariables #-}

9{-# LANGUAGE TypeFamilies #-}

10{-# LANGUAGE TypeOperators #-}

11{-# LANGUAGE UndecidableInstances #-}

12#ifdef USE_REFLEX_OPTIMIZER

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

14#endif

15module Reflex.PostBuild.Class

16 ( PostBuild (..)

17 ) where

19import Reflex.Class

21import Control.Monad.Reader

22import Control.Monad.State

23import qualified Control.Monad.State.Strict as Strict

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

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

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

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

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

30-- fire exactly once for an given action.

31class (Reflex t, Monad m) => PostBuild t m | m -> t where

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

33 getPostBuild :: m (Event t ())

35instance PostBuild t m => PostBuild t (ReaderT r m) where

36 getPostBuild = lift getPostBuild

38instance PostBuild t m => PostBuild t (StateT s m) where

39 getPostBuild = lift getPostBuild

41instance PostBuild t m => PostBuild t (Strict.StateT s m) where

42 getPostBuild = lift getPostBuild