8aef850 · text · git.iko.soy

git.iko.soy/text

Merge pull request #135 from paulcapron/master

Implement takeWhileEnd

commit8aef850cfd87a3df3785e527befe1ff61b23e249 authorBryan O'Sullivan <bos@serpentine.com> dateTue 22 Dec 2015, 11:08 (11 years ago) parent52f0946 7534f3c

3 files changed+43

compare with master

unifiedsplit

Data/Text.hs+22 Data/Text/Lazy.hs+15 tests/Tests/Properties.hs+6

Data/Text.hs+22

@@ -129,6 +129,7 @@ module Data.Text

129129 , drop

130130 , dropEnd

131131 , takeWhile

132+ , takeWhileEnd

132133 , dropWhile

133134 , dropWhileEnd

134135 , dropAround

@@ -1144,6 +1145,27 @@ takeWhile p t@(Text arr off len) = loop 0

11441145 unstream (S.takeWhile p (stream t)) = takeWhile p t

11451146 #-}

11461147

1148+-- | /O(n)/ 'takeWhileEnd', applied to a predicate @p@ and a 'Text',

1149+-- returns the longest suffix (possibly empty) of elements that

1150+-- satisfy @p@. Subject to fusion.

1151+-- Examples:

1152+--

1153+-- > takeWhileEnd (=='o') "foo" == "oo"

1154+takeWhileEnd :: (Char -> Bool) -> Text -> Text

1155+takeWhileEnd p t@(Text arr off len) = loop (len-1) len

1156+ where loop !i !l | l <= 0 = t

1157+ | p c = loop (i+d) (l+d)

1158+ | otherwise = text arr (off+l) (len-l)

1159+ where (c,d) = reverseIter t i

1160+{-# INLINE [1] takeWhileEnd #-}

1161+

1162+{-# RULES

1163+"TEXT takeWhileEnd -> fused" [~1] forall p t.

1164+ takeWhileEnd p t = S.reverse (S.takeWhile p (S.reverseStream t))

1165+"TEXT takeWhileEnd -> unfused" [1] forall p t.

1166+ S.reverse (S.takeWhile p (S.reverseStream t)) = takeWhileEnd p t

1167+ #-}

1168+

11471169-- | /O(n)/ 'dropWhile' @p@ @t@ returns the suffix remaining after

11481170-- 'takeWhile' @p@ @t@. Subject to fusion.

11491171dropWhile :: (Char -> Bool) -> Text -> Text

Data/Text/Lazy.hs+15

@@ -140,6 +140,7 @@ module Data.Text.Lazy

140140 , drop

141141 , dropEnd

142142 , takeWhile

143+ , takeWhileEnd

143144 , dropWhile

144145 , dropWhileEnd

145146 , dropAround

@@ -1139,6 +1140,20 @@ takeWhile p t0 = takeWhile' t0

11391140"LAZY TEXT takeWhile -> unfused" [1] forall p t.

11401141 unstream (S.takeWhile p (stream t)) = takeWhile p t

11411142 #-}

1143+-- | /O(n)/ 'takeWhileEnd', applied to a predicate @p@ and a 'Text',

1144+-- returns the longest suffix (possibly empty) of elements that

1145+-- satisfy @p@.

1146+-- Examples:

1147+--

1148+-- > takeWhileEnd (=='o') "foo" == "oo"

1149+takeWhileEnd :: (Char -> Bool) -> Text -> Text

1150+takeWhileEnd p = takeChunk empty . L.reverse . toChunks

1151+ where takeChunk acc [] = acc

1152+ takeChunk acc (t:ts) = if T.length t' < T.length t

1153+ then (Chunk t' acc)

1154+ else takeChunk (Chunk t' acc) ts

1155+ where t' = T.takeWhileEnd p t

1156+{-# INLINE takeWhileEnd #-}

11421157

11431158-- | /O(n)/ 'dropWhile' @p@ @t@ returns the suffix remaining after

11441159-- 'takeWhile' @p@ @t@. Subject to fusion.

tests/Tests/Properties.hs+6

@@ -516,6 +516,10 @@ sf_takeWhile q p = (L.takeWhile p . L.filter q) `eqP`

516516 (unpackS . S.takeWhile p . S.filter q)

517517t_takeWhile p = L.takeWhile p `eqP` (unpackS . T.takeWhile p)

518518tl_takeWhile p = L.takeWhile p `eqP` (unpackS . TL.takeWhile p)

519+t_takeWhileEnd p = (L.reverse . L.takeWhile p . L.reverse) `eqP`

520+ (unpackS . T.takeWhileEnd p)

521+tl_takeWhileEnd p = (L.reverse . L.takeWhile p . L.reverse) `eqP`

522+ (unpackS . TL.takeWhileEnd p)

519523s_dropWhile p = L.dropWhile p `eqP` (unpackS . S.dropWhile p)

520524s_dropWhile_s p = L.dropWhile p `eqP` (unpackS . S.unstream . S.dropWhile p)

521525sf_dropWhile q p = (L.dropWhile p . L.filter q) `eqP`

@@ -1142,6 +1146,8 @@ tests =

11421146 testProperty "sf_takeWhile" sf_takeWhile,

11431147 testProperty "t_takeWhile" t_takeWhile,

11441148 testProperty "tl_takeWhile" tl_takeWhile,

1149+ testProperty "t_takeWhileEnd" t_takeWhileEnd,

1150+ testProperty "tl_takeWhileEnd" tl_takeWhileEnd,

11451151 testProperty "sf_dropWhile" sf_dropWhile,

11461152 testProperty "s_dropWhile" s_dropWhile,

11471153 testProperty "s_dropWhile_s" s_dropWhile_s,