f336d57 · streamly · git.iko.soy

git.iko.soy/streamly

on master help sign in

Add intersperseSuffixBySpan

f336d57Harendra Kumar7 years ago

src/Streamly/Internal/Prelude.hs+17

compare with master

unifiedsplit

@@ -208,6 +208,7 @@ module Streamly.Internal.Prelude

208 , intersperseM

209 , intersperse

210 , intersperseSuffix

211+ , intersperseSuffixBySpan

211 -- , intersperseBySpan

212 -- , intersperseBySpan

212 , interjectSuffix

213 , interjectSuffix

213

214

@@ -1895,6 +1896,22 @@ intersperse a = fromStreamS . S.intersperse a . toStreamS

1895intersperseSuffix :: (IsStream t, MonadAsync m) => m a -> t m a -> t m a

1896intersperseSuffix :: (IsStream t, MonadAsync m) => m a -> t m a -> t m a

1896intersperseSuffix m = fromStreamD . D.intersperseSuffix m . toStreamD

1897intersperseSuffix m = fromStreamD . D.intersperseSuffix m . toStreamD

1897

1898

1899+-- | Like 'intersperseSuffix' but intersperses a monadic action into the input

1900+-- stream after every @n@ elements and after the last element.

1901+--

1902+-- @

1903+-- > S.toList $ S.intersperseSuffixBySpan 2 (return ',') $ S.fromList "hello"

1904+-- "he,ll,o,"

1905+-- @

1906+--

1907+-- /Internal/

1908+--

1909+{-# INLINE intersperseSuffixBySpan #-}

1910+intersperseSuffixBySpan :: (IsStream t, MonadAsync m)

1911+ => Int -> m a -> t m a -> t m a

1912+intersperseSuffixBySpan n eff =

1913+ fromStreamD . D.intersperseSuffixBySpan n eff . toStreamD

1914+

1898{-

1915{-

1899-- | Intersperse a monadic action into the input stream after every @n@

1916-- | Intersperse a monadic action into the input stream after every @n@

1900-- elements.

1917-- elements.

src/Streamly/Streams/StreamD.hs+34

@@ -244,6 +244,7 @@ module Streamly.Streams.StreamD

244 , intersperseM

245 , intersperse

246 , intersperseSuffix

247+ , intersperseSuffixBySpan

247 , insertBy

248 , insertBy

248

249

249 -- * Deleting

250 -- * Deleting

@@ -3266,6 +3267,39 @@ intersperseSuffix action (Stream step state) = Stream step' (SuffixElem state)

3266

3267

3267 step' _ (SuffixYield x next) = return $ Yield x next

3268 step' _ (SuffixYield x next) = return $ Yield x next

3268

3269

3270+data SuffixSpanState s a

3271+ = SuffixSpanElem s Int

3272+ | SuffixSpanSuffix s

3273+ | SuffixSpanYield a (SuffixSpanState s a)

3274+ | SuffixSpanLast

3275+ | SuffixSpanStop

3276+

3277+-- | intersperse after every n items

3278+{-# INLINE_NORMAL intersperseSuffixBySpan #-}

3279+intersperseSuffixBySpan :: forall m a. Monad m

3280+ => Int -> m a -> Stream m a -> Stream m a

3281+intersperseSuffixBySpan n action (Stream step state) =

3282+ Stream step' (SuffixSpanElem state n)

3283+ where

3284+ {-# INLINE_LATE step' #-}

3285+ step' gst (SuffixSpanElem st i) | i > 0 = do

3286+ r <- step gst st

3287+ return $ case r of

3288+ Yield x s -> Skip (SuffixSpanYield x (SuffixSpanElem s (i - 1)))

3289+ Skip s -> Skip (SuffixSpanElem s i)

3290+ Stop -> if i == n then Stop else Skip SuffixSpanLast

3291+ step' _ (SuffixSpanElem st _) = return $ Skip (SuffixSpanSuffix st)

3292+

3293+ step' _ (SuffixSpanSuffix st) = do

3294+ action >>= \r -> return $ Skip (SuffixSpanYield r (SuffixSpanElem st n))

3295+

3296+ step' _ (SuffixSpanLast) = do

3297+ action >>= \r -> return $ Skip (SuffixSpanYield r SuffixSpanStop)

3298+

3299+ step' _ (SuffixSpanYield x next) = return $ Yield x next

3300+

3301+ step' _ (SuffixSpanStop) = return Stop

3302+

3269{-# INLINE intersperse #-}

3303{-# INLINE intersperse #-}

3270intersperse :: Monad m => a -> Stream m a -> Stream m a

3304intersperse :: Monad m => a -> Stream m a -> Stream m a

3271intersperse a = intersperseM (return a)

3305intersperse a = intersperseM (return a)