7541131 · text · git.iko.soy

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Implement and test scanl1

7541131Bryan O'Sullivan18 years ago

Data/Text.hs+10−1

compare with master

unifiedsplit

@@ -75,7 +75,7 @@ module Data.Text

76 -- ** Scans

77 , scanl

78− -- , scanl1

78+ , scanl1

79 -- , scanr

80 -- , scanr1

@@ -495,6 +495,15 @@ scanl :: (Char -> Char -> Char) -> Char -> Text -> Text

495scanl f z t = unstream (S.scanl f z (stream t))

496{-# INLINE scanl #-}

497

498+-- | /O(n)/ 'scanl1' is a variant of 'scanl' that has no starting

499+-- value argument. This function is subject to array fusion.

500+--

501+-- > scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]

502+scanl1 :: (Char -> Char -> Char) -> Text -> Text

503+scanl1 f t | null t = empty

504+ | otherwise = scanl f (head t) (tail t)

505+{-# INLINE scanl1 #-}

506+

498-- -----------------------------------------------------------------------------

507-- -----------------------------------------------------------------------------

499-- ** Generating and unfolding 'Text's

508-- ** Generating and unfolding 'Text's

500

509

tests/Properties.hs+2

@@ -72,6 +72,7 @@ prop_maximum = L.maximum `eqEP` T.maximum

72prop_minimum = L.minimum `eqEP` T.minimum

74prop_scanl f z = L.scanl f z `eqP` (unpack . T.scanl f z)

75+prop_scanl1 f = L.scanl1 f `eqP` (unpack . T.scanl1 f)

76prop_replicate n = L.replicate n `eq` (unpack . T.replicate n)

77prop_replicate n = L.replicate n `eq` (unpack . T.replicate n)

77prop_unfoldr n = L.unfoldr f `eq` (unpack . T.unfoldr f)

78prop_unfoldr n = L.unfoldr f `eq` (unpack . T.unfoldr f)

@@ -159,6 +160,7 @@ tests = [

159 ("prop_minimum", mytest prop_minimum),

160 ("prop_minimum", mytest prop_minimum),

160

161

161 ("prop_scanl", mytest prop_scanl),

162 ("prop_scanl", mytest prop_scanl),

163+ ("prop_scanl1", mytest prop_scanl1),

162

164

163 ("prop_replicate", mytest prop_replicate),

165 ("prop_replicate", mytest prop_replicate),

164 ("prop_unfoldr", mytest prop_unfoldr),

166 ("prop_unfoldr", mytest prop_unfoldr),