e6699ec · streamly · git.iko.soy

git.iko.soy/streamly

Fix a bug in uniq function. Fixes #191.

commite6699ece2f391f8cfc5e91f414bfe8ba89127829 authorPranay Sashank <pranaysashank@gmail.com> dateWed 22 May 2019, 02:01 (7 years ago) parent6ed211f

2 files changed+18−4

compare with master

unifiedsplit

src/Streamly/Streams/StreamD.hs+1−1 test/Prop.hs+17−3

src/Streamly/Streams/StreamD.hs+1−1

@@ -2117,7 +2117,7 @@ uniq (Stream step state) = Stream step' (Nothing, state)

21172117 r <- step gst st

21182118 case r of

21192119 Yield y s | x == y -> return $ Skip (Just x, s)

2120− | otherwise -> return $ Yield x (Just y, s)

2120+ | otherwise -> return $ Yield y (Just y, s)

21212121 Skip s -> return $ Skip (Just x, s)

21222122 Stop -> return Stop

21232123

test/Prop.hs+17−3

@@ -578,7 +578,8 @@ transformCombineOpsOrdered constr desc eq t = do

578578 transform (dropWhile (> 0)) t (S.dropWhile (> 0))

579579 prop (desc <> " scan") $ transform (scanl' (+) 0) t (S.scanl' (+) 0)

580580

581− -- XXX add uniq

581+ prop (desc <> " uniq") $ transform referenceUniq t S.uniq

582+

582583 prop (desc <> " deleteBy (<=) 0") $

583584 transform (deleteBy (<=) 0) t (S.deleteBy (<=) 0)

584585

@@ -617,10 +618,23 @@ wrapOutOfBounds f i x | null x = Nothing

617618 | otherwise = Just (f x i)

618619

619620wrapThe :: Eq a => [a] -> Maybe a

620−wrapThe (x:xs) | all (x ==) xs = Just x

621− | otherwise = Nothing

621+wrapThe (x:xs)

622+ | all (x ==) xs = Just x

623+ | otherwise = Nothing

622624wrapThe [] = Nothing

623625

626+-- This is the reference uniq implementation to compare uniq against,

627+-- we can use uniq from vector package, but for now this should

628+-- suffice.

629+referenceUniq :: Eq a => [a] -> [a]

630+referenceUniq = go

631+ where

632+ go [] = []

633+ go (x:[]) = [x]

634+ go (x:y:xs)

635+ | x == y = go (x : xs)

636+ | otherwise = x : go (y : xs)

637+

624638eliminationOps

625639 :: ([Int] -> t IO Int)

626640 -> String