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Experimentation with Lift' on ContT
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runReaderInMonadReader :: (Member (Lift' m) r, MonadReader i m) | |
=> Sem (Reader i ': r) a | |
-> Sem r a | |
runReaderInMonadReader (Sem sem) = sem $ \u -> case decomp u of | |
Right (Yo e s wv ex _) -> case e of | |
Ask -> ex . (<$ s) <$> sendM' Control.Monad.Reader.ask | |
Local f m -> fmap ex $ withWeaving $ \s' wv' _ -> | |
Control.Monad.Reader.local | |
f | |
(wv' ( runReaderInMonadReader (wv (m <$ s)) <$ s')) | |
Left g -> liftSem $ hoist runReaderInMonadReader g | |
-- Way too janky. Plays badly with MonadState's that can fail. | |
runWriterInMonadState :: (Monoid s, Member (Lift' m) r, MonadState s m) | |
=> Sem (Writer s ': r) a | |
-> Sem r a | |
runWriterInMonadState = interpretH $ \case | |
Tell o -> do | |
a <- sendM' $ Control.Monad.State.modify (<> o) | |
pureT a | |
Listen m -> do | |
s <- sendM' $ Control.Monad.State.state (\s -> (s, mempty)) | |
m' <- runT m | |
res <- raise $ runWriterInMonadState m' | |
s' <- sendM' $ Control.Monad.State.state (\s' -> (s', s <> s')) | |
return ((,) s' <$> res) | |
Censor f m -> do | |
s <- sendM' $ Control.Monad.State.state (\s -> (s, mempty)) | |
m' <- runT m | |
res <- raise $ runWriterInMonadState m' | |
sendM' $ Control.Monad.State.modify (\s' -> s <> f s') | |
return res | |
callCC' :: Member (Lift' (ContT s m)) r | |
=> ((forall b. a -> Sem r b) -> Sem r a) | |
-> Sem r a | |
callCC' cc = withWeaving $ \s wv _ -> | |
ContT $ \c -> | |
runContT | |
(wv $ | |
cc (\a -> sendM' . ContT $ \_ -> c (a <$ s)) | |
<$ s) | |
c | |
shift' :: (Monad m, Member (Lift' (ContT (Maybe s) m)) r) | |
=> ((a -> Sem r (Maybe s)) -> Sem r (Maybe s)) | |
-> Sem r a | |
shift' cc = withWeaving $ \s wv ins -> | |
ContT $ \c -> | |
runContT | |
(wv $ | |
cc (\a -> sendM' . ContT $ \c' -> c (a <$ s) >>= c') | |
<$ s) | |
(pure . join . ins) | |
test1 :: IO (Int, String) | |
test1 = | |
(`runStateT` mempty) | |
. (`runReaderT` 1) | |
. (`runContT` pure) | |
. runM' | |
. runWriterInMonadState | |
. runReaderInMonadReader $ do | |
tell "abra | |
callCC' $ \c -> | |
local (+1) $ censor (\_ -> "") (c ()) | |
i <- ask | |
tell "hadabra" | |
return i | |
-- test1 == (2, "hadabra") | |
-- This is runWriterInMonadState's fault, not callCC'. | |
test2 :: IO (Maybe Int, String) | |
test2 = | |
(`runStateT` mempty) | |
. (`runReaderT` 1) | |
. (`runContT` pure) | |
. runM' | |
. runWriterInMonadState | |
. runReaderInMonadReader $ do | |
tell "abra" | |
shift' $ \c -> | |
local (+1) $ censor (\_ -> "") (c ()) | |
i <- ask | |
tell "hadabra" | |
return (Just i) | |
-- test2 == (Just 2, "abra") |
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