reflex
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EventWriterT could be more general
I found myself wanting a different event combination strategy than using merge
when using EventWriterT
.
Therefore I generalised the type of tellEvent
to
class (Monad m, Semigroup w) => EventWriter t (f :: * -> *) w m | m -> t w where
tellEventF :: f (Event t w) -> m ()
and implementing a running function which returned a list of the wrapped events rather than
always combining them with merge
.
-- | Run a 'EventWriterT' action.
runEventWriterTWithComb :: forall t f m a r. (Reflex t, Monad m)
=> EventWriterT t f r m a
-> m (a, [f (Event t r)])
runEventWriterTWithComb (EventWriterT a) = do
(result, requests) <- runStateT a $ EventWriterState (-1) []
let combineResults :: DMap (TellId r) (Compose f (Event t)) -> [f (Event t r)]
combineResults =
DMap.foldlWithKey (\vs tid (Compose v) -> withTellIdRefl tid $ v : vs) [] -- This is where we finally reverse the DMap to get things in the correct order
let e = combineResults $ DMap.fromDistinctAscList $ _eventWriterState_told requests
return (result, e)
https://github.com/mpickering/reflex/commit/cf216f37f98abedbaa9f0946a45674a139db59a0