3082345 · streamly · git.iko.soy

git.iko.soy/streamly

Fix take, takeEQ, takeGE, sliceSepByMax.

- `take`, `takeEQ`, `takeGE` now work when the count is <0. - `sliceSepByMax` behaviour is now more in line with what the documentaton says in `Streamly.Internal.Data.Parser`.

commit30823452a446e1956a65597290d14d07341757e1 authorpranaysashank <pranaysashank@composewell.com> dateSun 28 Jun 2020, 21:33 (6 years ago) parent1100c23

2 files changed+41−23

compare with master

unifiedsplit

src/Streamly/Internal/Data/Parser.hs+10 src/Streamly/Internal/Data/Parser/ParserD.hs+31−23

src/Streamly/Internal/Data/Parser.hs+10

@@ -381,6 +381,9 @@ satisfy = D.toParserK . D.satisfy

381381-- >>> S.parse (PR.take 1 FL.toList) $ S.fromList [1]

382382-- [1]

383383--

384+-- >>> S.parse (PR.take (-1) FL.toList) $ S.fromList [1]

385+-- []

386+--

384387-- @

385388-- S.chunksOf n f = S.splitParse (FL.take n f)

386389-- @

@@ -515,6 +518,13 @@ sliceBeginWith = undefined

515518-- hybrid of 'splitOn' and 'take'. The element on which the condition succeeds

516519-- is dropped.

517520--

521+-- >>> even n = n `mod` 2 == 0

522+-- >>> S.parse (PR.many FL.toList (PR.sliceSepByMax (==1) 5 FL.toList)) $ S.fromList [1..10]

523+-- > [[],[2,3,4,5,6],[7,8,9,10]]

524+--

525+-- >>> S.parse (PR.many FL.toList (PR.sliceSepByMax even 10 FL.toList)) $ S.fromList [0..10]

526+-- > [[],[1],[3],[5],[7],[9],[]]

527+--

518528-- /Internal/

519529--

520530{-# INLINABLE sliceSepByMax #-}

src/Streamly/Internal/Data/Parser/ParserD.hs+31−23

@@ -316,13 +316,15 @@ take n (Fold fstep finitial fextract) = Parser step initial extract

316316

317317 initial = Tuple' 0 <$> finitial

318318

319− step (Tuple' i r) a = do

320− res <- fstep r a

321− let i1 = i + 1

322− s1 = Tuple' i1 res

323− if i1 < n

324− then return $ Partial 0 s1

325− else Done 0 <$> fextract res

319+ step (Tuple' i r) a

320+ | i < n = do

321+ res <- fstep r a

322+ let i1 = i + 1

323+ s1 = Tuple' i1 res

324+ if i1 < n

325+ then return $ Partial 0 s1

326+ else Done 0 <$> fextract res

327+ | otherwise = Done 1 <$> fextract r

326328

327329 extract (Tuple' _ r) = fextract r

328330

@@ -338,11 +340,15 @@ takeEQ n (Fold fstep finitial fextract) = Parser step initial extract

338340

339341 initial = Tuple' 0 <$> finitial

340342

341− step (Tuple' i r) a = do

342− res <- fstep r a

343− let i1 = i + 1

344− s1 = Tuple' i1 res

345− if i1 < n then return (Continue 0 s1) else Done 0 <$> fextract res

343+ step (Tuple' i r) a

344+ | i < n = do

345+ res <- fstep r a

346+ let i1 = i + 1

347+ s1 = Tuple' i1 res

348+ if i1 < n

349+ then return (Continue 0 s1)

350+ else Done 0 <$> fextract res

351+ | otherwise = Done 1 <$> fextract r

346352

347353 extract (Tuple' i r) =

348354 if n == i

@@ -361,10 +367,11 @@ takeEQ n (Fold fstep finitial fextract) = Parser step initial extract

361367--

362368{-# INLINE takeGE #-}

363369takeGE :: MonadThrow m => Int -> Fold m a b -> Parser m a b

364−takeGE n (Fold fstep finitial fextract) = Parser step initial extract

365−

370+takeGE cnt (Fold fstep finitial fextract) = Parser step initial extract

366371 where

367372

373+ n = max cnt 0

374+

368375 initial = Tuple' 0 <$> finitial

369376

370377 step (Tuple' i r) a = do

@@ -489,17 +496,18 @@ sliceSepByMax predicate cnt (Fold fstep finitial fextract) =

489496 where

490497

491498 initial = Tuple' 0 <$> finitial

499+

492500 step (Tuple' i r) a

493− | not (predicate a) = do

494− res <- fstep r a

495− let i1 = i + 1

496− s1 = Tuple' i1 res

497− if i1 < cnt

498− then return $ Partial 0 s1

499− else do

500− b <- fextract res

501− return $ Done 0 b

501+ | not (predicate a) =

502+ if i < cnt

503+ then do

504+ res <- fstep r a

505+ let i1 = i + 1

506+ s1 = Tuple' i1 res

507+ return $ Partial 0 s1

508+ else Done 1 <$> fextract r

502509 | otherwise = Done 0 <$> fextract r

510+

503511 extract (Tuple' _ r) = fextract r

504512

505513-- | See 'Streamly.Internal.Data.Parser.wordBy'.