Remove Functor from stream

Author: dagit

src/Control/Monad/Logic/Sequence/Internal.hs

@@ -145,9 +145,11 @@ data StreamM m a = forall s. StreamM (s -> m (Step s a)) s
 stream :: Monad m => SeqT m a -> StreamM m a
 stream m = StreamM next m where
   {-# INLINE next #-}
-  next s = step <$> toView s
-  step Empty = Done
-  step (h :< t) = Yield h t
+  next s = do
+    x <- toView s
+    case x of
+      Empty -> return Done
+      h :< t -> return (Yield h t)
 {-# INLINE[1] stream #-}
 
 unstream :: Monad m => StreamM m a -> SeqT m a