527ab96 · streamly · git.iko.soy

git.iko.soy/streamly

Use StreamD versions for null/head

findIndex benchmark improves quite a bit with that. When using `head` from StreamK, findIndex degraded significantly when using bigger value of -fmax-worker-args.

commit527ab96060ea07e3df29cde6fea9f7a2beb423c2 authorHarendra Kumar <harendra.kumar@gmail.com> dateThu 22 Aug 2019, 20:27 (7 years ago) parent17b7d92

2 files changed+2−3

compare with master

unifiedsplit

src/Streamly/Prelude/Internal.hs+2−2 src/Streamly/Streams/StreamD.hs−1

src/Streamly/Prelude/Internal.hs+2−2

@@ -1024,7 +1024,7 @@ runWhile = drainWhile

10241024-- @since 0.1.1

10251025{-# INLINE null #-}

10261026null :: Monad m => SerialT m a -> m Bool

1027−null = K.null

1027+null = S.null . toStreamS

10281028

10291029-- | Extract the first element of the stream, if any.

10301030--

@@ -1033,7 +1033,7 @@ null = K.null

10331033-- @since 0.1.0

10341034{-# INLINE head #-}

10351035head :: Monad m => SerialT m a -> m (Maybe a)

1036−head = K.head

1036+head = S.head . toStreamS

10371037

10381038-- |

10391039-- > tail = fmap (fmap snd) . uncons

src/Streamly/Streams/StreamD.hs−1

@@ -648,7 +648,6 @@ drain (Stream step state) = go SPEC state

648648null :: Monad m => Stream m a -> m Bool

649649null m = foldrM (\_ _ -> return False) (return True) m

650650

651−-- XXX SPEC?

652651{-# INLINE_NORMAL head #-}

653652head :: Monad m => Stream m a -> m (Maybe a)

654653head m = foldrM (\x _ -> return (Just x)) (return Nothing) m