0e900a7 · reflex · git.iko.soy

Add PerformEvent and TriggerEvent instances for MaybeT

commit0e900a7712d6d14776b57a98401b6a56e1b1bcec authorTom Smalley <tfsmalley@gmail.com> dateWed 26 Feb 2020, 17:45 (7 years ago) parentde9d2b0

2 files changed+12

unifiedsplit

src/Reflex/PerformEvent/Class.hs+6

@@ -22,6 +22,7 @@ import Reflex.Class

2222import Reflex.TriggerEvent.Class

2323

2424import Control.Monad.Reader

25+import Control.Monad.Trans.Maybe (MaybeT (..))

2526

2627-- | 'PerformEvent' represents actions that can trigger other actions based on

2728-- 'Event's.

@@ -61,3 +62,8 @@ instance PerformEvent t m => PerformEvent t (ReaderT r m) where

6162 performEvent e = do

6263 r <- ask

6364 lift $ performEvent $ flip runReaderT r <$> e

65+

66+instance PerformEvent t m => PerformEvent t (MaybeT m) where

67+ type Performable (MaybeT m) = MaybeT (Performable m)

68+ performEvent_ = lift . performEvent_ . fmapCheap (void . runMaybeT)

69+ performEvent = lift . fmap (fmapMaybe id) . performEvent . fmapCheap runMaybeT

src/Reflex/TriggerEvent/Class.hs+6

@@ -12,6 +12,7 @@ import Reflex.Class

1212import Control.Monad.Reader

1313import Control.Monad.State

1414import qualified Control.Monad.State.Strict as Strict

15+import Control.Monad.Trans.Maybe (MaybeT)

1516

1617--TODO: Shouldn't have IO hard-coded

1718-- | 'TriggerEvent' represents actions that can create 'Event's that can be

@@ -47,3 +48,8 @@ instance TriggerEvent t m => TriggerEvent t (Strict.StateT s m) where

4748 newTriggerEvent = lift newTriggerEvent

4849 newTriggerEventWithOnComplete = lift newTriggerEventWithOnComplete

4950 newEventWithLazyTriggerWithOnComplete = lift . newEventWithLazyTriggerWithOnComplete

51+

52+instance TriggerEvent t m => TriggerEvent t (MaybeT m) where

53+ newTriggerEvent = lift newTriggerEvent

54+ newTriggerEventWithOnComplete = lift newTriggerEventWithOnComplete

55+ newEventWithLazyTriggerWithOnComplete = lift . newEventWithLazyTriggerWithOnComplete