6e5bf43 · text · git.iko.soy

git.iko.soy/text

Implement findIndices.

--HG-- extra : convert_revision : 1859be7307cbd3079168f80e15162a1e6b6ffd6e

commit6e5bf43fbbb4ecd599e5af9095b8fe0fe8e54bb1 authorBryan O'Sullivan <bos@serpentine.com> dateThu 12 Feb 2009, 09:07 (18 years ago) parentb216a25

3 files changed+29−9

compare with master

unifiedsplit

Data/Text.hs+13−5 Data/Text/Fusion.hs+14−4 tests/Properties.hs+2

Data/Text.hs+13−5

@@ -130,7 +130,7 @@ module Data.Text

130130 -- * Indexing

131131 , index

132132 , findIndex

133− -- , findIndices

133+ , findIndices

134134 , elemIndex

135135 -- , elemIndices

136136 -- , count

@@ -823,16 +823,24 @@ index :: Text -> Int -> Char

823823index t n = S.index (stream t) n

824824{-# INLINE index #-}

825825

826−-- | The 'findIndex' function takes a predicate and a 'Text' and

827−-- returns the index of the first element in the 'Text'

828−-- satisfying the predicate.

826+-- | /O(n)/ The 'findIndex' function takes a predicate and a 'Text'

827+-- and returns the index of the first element in the 'Text' satisfying

828+-- the predicate. This function is subject to fusion.

829829findIndex :: (Char -> Bool) -> Text -> Maybe Int

830830findIndex p t = S.findIndex p (stream t)

831831{-# INLINE findIndex #-}

832832

833+-- | The 'findIndices' function extends 'findIndex', by returning the

834+-- indices of all elements satisfying the predicate, in ascending

835+-- order. This function is subject to fusion.

836+findIndices :: (Char -> Bool) -> Text -> [Int]

837+findIndices p t = S.findIndices p (stream t)

838+{-# INLINE findIndices #-}

839+

833840-- | /O(n)/ The 'elemIndex' function returns the index of the first

834841-- element in the given 'Text' which is equal to the query element, or

835−-- 'Nothing' if there is no such element.

842+-- 'Nothing' if there is no such element. This function is subject to

843+-- fusion.

836844elemIndex :: Char -> Text -> Maybe Int

837845elemIndex c t = S.elemIndex c (stream t)

838846

Data/Text/Fusion.hs+14−4

@@ -90,6 +90,7 @@ module Data.Text.Fusion

9090 , find

9191 , index

9292 , findIndex

93+ , findIndices

9394 , findIndexOrEnd

9495 , elemIndex

9596

@@ -784,14 +785,23 @@ index (Stream next s0 _len) n0

784785-- returns the index of the first element in the stream

785786-- satisfying the predicate.

786787findIndex :: (Char -> Bool) -> Stream Char -> Maybe Int

787−findIndex p (Stream next s0 _len) = loop_findIndex 0 s0

788+findIndex p s = case findIndices p s of

789+ (i:_) -> Just i

790+ _ -> Nothing

791+{-# INLINE [0] findIndex #-}

792+

793+-- | The 'findIndices' function takes a predicate and a stream and

794+-- returns all indices of the elements in the stream

795+-- satisfying the predicate.

796+findIndices :: (Char -> Bool) -> Stream Char -> [Int]

797+findIndices p (Stream next s0 _len) = loop_findIndex 0 s0

788798 where

789799 loop_findIndex !i !s = case next s of

790− Done -> Nothing

800+ Done -> []

791801 Skip s' -> loop_findIndex i s' -- hmm. not caught by QC

792− Yield x s' | p x -> Just i

802+ Yield x s' | p x -> i : loop_findIndex (i+1) s'

793803 | otherwise -> loop_findIndex (i+1) s'

794−{-# INLINE [0] findIndex #-}

804+{-# INLINE [0] findIndices #-}

795805

796806-- | The 'findIndexOrEnd' function takes a predicate and a stream and

797807-- returns the index of the first element in the stream

tests/Properties.hs+2

@@ -162,6 +162,7 @@ prop_partition p = L.partition p `eqP` (unpack2 . T.partition p)

162162prop_index x s = x < L.length s && x >= 0 ==>

163163 (L.!!) s x == T.index (pack s) x

164164prop_findIndex p = L.findIndex p `eqP` T.findIndex p

165+prop_findIndices p = L.findIndices p`eqP` T.findIndices p

165166prop_elemIndex c = L.elemIndex c `eqP` T.elemIndex c

166167prop_zipWith c s = L.zipWith c s `eqP` (unpack . T.zipWith c (pack s))

167168

@@ -264,6 +265,7 @@ tests = [

264265

265266 ("prop_index", mytest prop_index),

266267 ("prop_findIndex", mytest prop_findIndex),

268+ ("prop_findIndices", mytest prop_findIndices),

267269 ("prop_elemIndex", mytest prop_elemIndex),

268270 ("prop_zipWith", mytest prop_zipWith)

269271 ]