d4bef2e · streamly · git.iko.soy

git.iko.soy/streamly

Add intersperse to Streamly.Prelude.

- Also adds benchmarking code for intersperse.

commitd4bef2e352fd5f0b47c7685595a2d193bbdadbd9 authorPranay Sashank <pranaysashank@gmail.com> dateMon 10 Jun 2019, 14:15 (7 years ago) parent254f27f

10 files changed+75−5

compare with master

unifiedsplit

Changelog.md+2 benchmark/BaseStreams.hs+6 benchmark/Linear.hs+2 benchmark/LinearOps.hs+3−1 benchmark/StreamDOps.hs+3−1 benchmark/StreamKOps.hs+4−1 src/Streamly/Prelude.hs+15−1 src/Streamly/Streams/StreamD.hs+34 src/Streamly/Streams/StreamK.hs+5 src/Streamly/String.hs+1−1

Changelog.md+2

@@ -66,6 +66,8 @@ example, concat streams concurrently using this.

6666 * `reverse'` a several times faster reverse using Storable instance

6767 * `intersperseByTime` intersperse a mondadic action in a stream

6868 periodically

69+ * `intersperse` intersperse an element in between consecutive elements in

70+ stream

6971

7072### Deprecations

7173

benchmark/BaseStreams.hs+6

@@ -101,6 +101,8 @@ main =

101101 , benchIO "mapMaybeM" (D.mapMaybeM 1) D.sourceUnfoldrM

102102 , benchIO "concatMap" (D.concatMap 1) (D.sourceUnfoldrMN D.value2)

103103 , benchIO "concatMapPure" (D.concatMap 1) (D.sourceUnfoldrN D.value2)

104+ , benchIO "intersperse" (D.intersperse 1) (D.sourceUnfoldrMN D.value2)

105+ , benchIO "interspersePure" (D.intersperse 1) (D.sourceUnfoldrN D.value2)

104106 -- , benchIO "foldrS" (D.foldrS 1) D.sourceUnfoldrM

105107 -- This has horrible performance, never finishes

106108 -- , benchIO "foldlS" (D.foldlS 1) D.sourceUnfoldrM

@@ -113,6 +115,7 @@ main =

113115 , benchIO "mapMaybe" (D.mapMaybe 4) D.sourceUnfoldrM

114116 , benchIO "mapMaybeM" (D.mapMaybeM 4) D.sourceUnfoldrM

115117 -- , benchIO "concatMap" (D.concatMap 4) (D.sourceUnfoldrMN D.value16)

118+ , benchIO "intersperse" (D.intersperse 4) (D.sourceUnfoldrMN D.value16)

116119 ]

117120 , bgroup "filtering"

118121 [ benchIO "filter-even" (D.filterEven 1) D.sourceUnfoldrM

@@ -242,6 +245,8 @@ main =

242245 -- , benchIOSrcK "concatMap" K.concatMap

243246 , benchIO "concatMap" (K.concatMap 1) (K.sourceUnfoldrMN K.value2)

244247 , benchIO "concatMapPure" (K.concatMap 1) (K.sourceUnfoldrN K.value2)

248+ , benchIO "intersperse" (K.intersperse 1) (K.sourceUnfoldrMN K.value2)

249+ , benchIO "interspersePure" (K.intersperse 1) (K.sourceUnfoldrN K.value2)

245250 , benchIO "foldlS" (K.foldlS 1) K.sourceUnfoldrM

246251 ]

247252 , bgroup "transformationX4"

@@ -251,6 +256,7 @@ main =

251256 , benchIO "mapM" (K.mapM 4) K.sourceUnfoldrM

252257 , benchIO "mapMSerial" (K.mapMSerial 4) K.sourceUnfoldrM

253258 -- , benchIO "concatMap" (K.concatMap 4) (K.sourceUnfoldrMN K.value16)

259+ , benchIO "intersperse" (K.intersperse 4) (K.sourceUnfoldrMN K.value16)

254260 ]

255261 , bgroup "filtering"

256262 [ benchIO "filter-even" (K.filterEven 1) K.sourceUnfoldrM

benchmark/Linear.hs+2

@@ -300,6 +300,7 @@ main =

300300 --, benchIOSink "dropWhileM-true" (Ops.dropWhileMTrue 1)

301301 , benchIOSink "dropWhile-false" (Ops.dropWhileFalse 1)

302302 , benchIOSink "deleteBy" (Ops.deleteBy 1)

303+ , benchIOSink "intersperse" (Ops.intersperse 1)

303304 , benchIOSink "insertBy" (Ops.insertBy 1)

304305 ]

305306 , bgroup "filteringX4"

@@ -315,6 +316,7 @@ main =

315316 --, benchIOSink "dropWhileM-true" (Ops.dropWhileMTrue 4)

316317 , benchIOSink "dropWhile-false" (Ops.dropWhileFalse 4)

317318 , benchIOSink "deleteBy" (Ops.deleteBy 4)

319+ , benchIOSink "intersperse" (Ops.intersperse 4)

318320 , benchIOSink "insertBy" (Ops.insertBy 4)

319321 ]

320322 , bgroup "multi-stream"

benchmark/LinearOps.hs+3−1

@@ -357,7 +357,8 @@ scan, scanl1', map, fmap, mapMaybe, filterEven, filterAllOut,

357357 => Int -> Stream m Int -> m ()

358358

359359{-# INLINE mapMaybeM #-}

360−mapMaybeM :: S.MonadAsync m => Int -> Stream m Int -> m ()

360+{-# INLINE intersperse #-}

361+mapMaybeM, intersperse :: S.MonadAsync m => Int -> Stream m Int -> m ()

361362

362363{-# INLINE mapM #-}

363364{-# INLINE transformMapM #-}

@@ -415,6 +416,7 @@ dropWhileMTrue n = composeN n $ S.dropWhileM (return . (<= maxValue))

415416dropWhileFalse n = composeN n $ S.dropWhile (> maxValue)

416417findIndices n = composeN n $ S.findIndices (== maxValue)

417418elemIndices n = composeN n $ S.elemIndices maxValue

419+intersperse n = composeN n $ S.intersperse maxValue

418420insertBy n = composeN n $ S.insertBy compare maxValue

419421deleteBy n = composeN n $ S.deleteBy (>=) maxValue

420422reverse n = composeN n $ S.reverse

benchmark/StreamDOps.hs+3−1

@@ -177,10 +177,11 @@ composeN n f =

177177{-# INLINE foldrS #-}

178178{-# INLINE foldlS #-}

179179{-# INLINE concatMap #-}

180+{-# INLINE intersperse #-}

180181scan, map, fmap, mapM, mapMaybe, mapMaybeM, filterEven, filterAllOut,

181182 filterAllIn, takeOne, takeAll, takeWhileTrue, takeWhileMTrue, dropOne,

182183 dropAll, dropWhileTrue, dropWhileMTrue, dropWhileFalse, foldrS, foldlS,

183− concatMap

184+ concatMap, intersperse

184185 :: Monad m

185186 => Int -> Stream m Int -> m ()

186187

@@ -207,6 +208,7 @@ dropWhileFalse n = composeN n $ S.dropWhile (> maxValue)

207208foldrS n = composeN n $ S.foldrS S.cons S.nil

208209foldlS n = composeN n $ S.foldlS (flip S.cons) S.nil

209210concatMap n = composeN n $ (\s -> S.concatMap (\_ -> s) s)

211+intersperse n = composeN n $ S.intersperse maxValue

210212

211213-------------------------------------------------------------------------------

212214-- Iteration

benchmark/StreamKOps.hs+4−1

@@ -205,7 +205,9 @@ scan, map, fmap, filterEven, filterAllOut,

205205

206206{-# INLINE mapM #-}

207207{-# INLINE mapMSerial #-}

208−mapM, mapMSerial :: S.MonadAsync m => Int -> Stream m Int -> m ()

208+{-# INLINE intersperse #-}

209+mapM, mapMSerial, intersperse

210+ :: S.MonadAsync m => Int -> Stream m Int -> m ()

209211

210212scan n = composeN n $ S.scanl' (+) 0

211213map n = composeN n $ P.fmap (+1)

@@ -224,6 +226,7 @@ dropWhileTrue n = composeN n $ S.dropWhile (<= maxValue)

224226dropWhileFalse n = composeN n $ S.dropWhile (<= 1)

225227foldlS n = composeN n $ S.foldlS (flip S.cons) S.nil

226228concatMap n = composeN n $ (\s -> S.concatMap (\_ -> s) s)

229+intersperse n = composeN n $ S.intersperse maxValue

227230

228231-------------------------------------------------------------------------------

229232-- Iteration

src/Streamly/Prelude.hs+15−1

@@ -369,6 +369,7 @@ module Streamly.Prelude

369369

370370 , insertBy

371371 , intersperseM

372+ , intersperse

372373 -- , intersperseBySpan

373374 , intersperseByTime

374375

@@ -1933,7 +1934,20 @@ reverse' s = fromStreamD $ D.reverse' $ toStreamD s

19331934-- @since 0.5.0

19341935{-# INLINE intersperseM #-}

19351936intersperseM :: (IsStream t, MonadAsync m) => m a -> t m a -> t m a

1936−intersperseM = K.intersperseM

1937+intersperseM m = fromStreamS . S.intersperseM m . toStreamS

1938+

1939+-- | Generate a stream by inserting a given element between consecutive

1940+-- elements of the given stream.

1941+--

1942+-- @

1943+-- > S.toList $ S.intersperse ',' $ S.fromList "hello"

1944+-- "h,e,l,l,o"

1945+-- @

1946+--

1947+-- @since 0.7.0

1948+{-# INLINE intersperse #-}

1949+intersperse :: (IsStream t, MonadAsync m) => a -> t m a -> t m a

1950+intersperse a = fromStreamS . S.intersperse a . toStreamS

19371951

19381952{-

19391953-- | Intersperse a monadic action into the input stream after every @n@

src/Streamly/Streams/StreamD.hs+34

@@ -203,6 +203,8 @@ module Streamly.Streams.StreamD

203203 , sequence

204204

205205 -- * Inserting

206+ , intersperseM

207+ , intersperse

206208 , insertBy

207209

208210 -- * Deleting

@@ -2174,6 +2176,38 @@ sequence (Stream step state) = Stream step' state

21742176-- Inserting

21752177------------------------------------------------------------------------------

21762178

2179+data LoopState x s = FirstYield s

2180+ | InterspersingYield s

2181+ | YieldAndCarry x s

2182+

2183+{-# INLINE_NORMAL intersperseM #-}

2184+intersperseM :: Monad m => m a -> Stream m a -> Stream m a

2185+intersperseM m (Stream step state) = Stream step' (FirstYield state)

2186+ where

2187+ {-# INLINE_LATE step' #-}

2188+ step' gst (FirstYield st) = do

2189+ r <- step gst st

2190+ return $

2191+ case r of

2192+ Yield x s -> Skip (YieldAndCarry x s)

2193+ Skip s -> Skip (FirstYield s)

2194+ Stop -> Stop

2195+

2196+ step' gst (InterspersingYield st) = do

2197+ r <- step gst st

2198+ case r of

2199+ Yield x s -> do

2200+ a <- m

2201+ return $ Yield a (YieldAndCarry x s)

2202+ Skip s -> return $ Skip $ InterspersingYield s

2203+ Stop -> return Stop

2204+

2205+ step' _ (YieldAndCarry x st) = return $ Yield x (InterspersingYield st)

2206+

2207+{-# INLINE intersperse #-}

2208+intersperse :: Monad m => a -> Stream m a -> Stream m a

2209+intersperse a = intersperseM (return a)

2210+

21772211{-# INLINE_NORMAL insertBy #-}

21782212insertBy :: Monad m => (a -> a -> Ordering) -> a -> Stream m a -> Stream m a

21792213insertBy cmp a (Stream step state) = Stream step' (state, False, Nothing)

src/Streamly/Streams/StreamK.hs+5

@@ -143,6 +143,7 @@ module Streamly.Streams.StreamK

143143

144144 -- ** Inserting

145145 , intersperseM

146+ , intersperse

146147 , insertBy

147148

148149 -- ** Deleting

@@ -826,6 +827,10 @@ intersperseM a m = prependingStart m

826827 yieldk i x = foldStreamShared st yld sng stp $ a |: return i |: go x

827828 in foldStream st yieldk single stp m2

828829

830+{-# INLINE intersperse #-}

831+intersperse :: (IsStream t, MonadAsync m) => a -> t m a -> t m a

832+intersperse a = intersperseM (return a)

833+

829834{-# INLINE insertBy #-}

830835insertBy :: IsStream t => (a -> a -> Ordering) -> a -> t m a -> t m a

831836insertBy cmp x m = go m

src/Streamly/String.hs+1−1

@@ -191,4 +191,4 @@ unlines = D.fromStreamD . A.unlines . D.toStreamD

191191

192192{-# INLINE unwords #-}

193193unwords :: (MonadAsync m, IsStream t) => t m (Array Char) -> t m Char

194−unwords = A.flattenArrays . (S.intersperseM (return $ A.fromList " "))

194+unwords = A.flattenArrays . (S.intersperse (A.fromList " "))