@@ -1589,18 +1589,16 @@ scanl1' step m = fromStreamD $ D.scanl1' step $ toStreamD m
15891589--
15901590-- @since 0.7.0
15911591{-# INLINE scan #-}
1592−scan :: Monad m => Fold m a b -> SerialT m a -> SerialT m b
1592+scan :: (IsStream t, Monad m) => Fold m a b -> t m a -> t m b
15931593scan (Fold step begin done) = P.scanlMx' step begin done
15941594
15951595-- | Postscan a stream using the given monadic fold.
15961596--
15971597-- @since 0.7.0
15981598{-# INLINE postscan #-}
1599−postscan :: Monad m => Fold m a b -> SerialT m a -> SerialT m b
1599+postscan :: (IsStream t, Monad m) => Fold m a b -> t m a -> t m b
16001600postscan (Fold step begin done) = P.postscanlMx' step begin done
16011601
1602−-- XXX runPrescan
1603−
16041602------------------------------------------------------------------------------
16051603-- Transformation by Filtering
16061604------------------------------------------------------------------------------