1ab2878 · streamly · git.iko.soy

git.iko.soy/streamly

Expose groupsOf from Data.Stream (#2372)

commit1ab2878ecad6a12279f4f56e851763e06426c835 authorRanjeet Ranjan <ranjeetr@composewell.com> dateTue 4 Jul 2023, 23:07 (3 years ago) parentf1be90c

5 files changed+53

compare with master

unifiedsplit

core/src/Streamly/Data/Stream.hs+1 core/src/Streamly/Internal/Data/Stream/StreamD/Type.hs+11 hie.yaml+2 test/Streamly/Test/Data/Stream.hs+33 test/streamly-tests.cabal+6

core/src/Streamly/Data/Stream.hs+1

@@ -431,6 +431,7 @@ module Streamly.Data.Stream

431431 -- >>> wordsBy p f = Stream.parseMany (Parser.wordBy p f)

432432 -- >>> groupsOf n f = Stream.foldMany (Fold.take n f)

433433 , foldMany -- XXX Rename to foldRepeat

434+ , groupsOf

434435 , parseMany

435436 , Array.chunksOf

436437

core/src/Streamly/Internal/Data/Stream/StreamD/Type.hs+11

@@ -1903,6 +1903,17 @@ foldMany (Fold fstep initial extract) (Stream step state) =

19031903 step' _ (FoldManyYield b next) = return $ Yield b next

19041904 step' _ FoldManyDone = return Stop

19051905

1906+-- | Group the input stream into groups of @n@ elements each and then fold each

1907+-- group using the provided fold function.

1908+--

1909+-- @groupsOf n f = foldMany (FL.take n f)@

1910+--

1911+-- >>> Stream.toList $ Stream.groupsOf 2 Fold.sum (Stream.enumerateFromTo 1 10)

1912+-- [3,7,11,15,19]

1913+--

1914+-- This can be considered as an n-fold version of 'take' where we apply

1915+-- 'take' repeatedly on the leftover stream until the stream exhausts.

1916+--

19061917{-# INLINE groupsOf #-}

19071918groupsOf :: Monad m => Int -> Fold m a b -> Stream m a -> Stream m b

19081919groupsOf n f = foldMany (FL.take n f)

hie.yaml+2

@@ -94,6 +94,8 @@ cradle:

9494 cabal:

9595 - path: "./test/Streamly/Test/Data/Array.hs"

9696 component: "test:Data.Array"

97+ - path: "./test/Streamly/Test/Data/Stream.hs"

98+ component: "test:Data.Stream"

9799 - path: "./test/Streamly/Test/Data/Array/Generic.hs"

98100 component: "test:Data.Array.Generic"

99101 - path: "./test/Streamly/Test/Data/Array/Mut.hs"

test/Streamly/Test/Data/Stream.hsnew file+33

@@ -0,0 +1,33 @@

1+-- |

2+-- Module : Streamly.Test.Data.Stream

4+-- License : BSD-3-Clause

5+-- Maintainer : streamly@composewell.com

6+-- Stability : experimental

7+-- Portability : GHC

9+module Streamly.Test.Data.Stream (main) where

10+

11+import qualified Streamly.Data.Fold as Fold

12+import qualified Streamly.Data.Stream as Stream

13+

14+import Test.Hspec.QuickCheck

15+import Test.Hspec as H

16+

17+moduleName :: String

18+moduleName = "Data.Stream"

19+

20+testgroupsOf :: Expectation

21+testgroupsOf =

22+ Stream.toList

23+ (Stream.groupsOf 2 Fold.sum (Stream.enumerateFromTo 1 10))

24+ `shouldReturn` [3::Int, 7, 11, 15, 19]

25+

26+main :: IO ()

27+main =

28+ hspec $

29+ H.parallel $

30+ modifyMaxSuccess (const 1) $ do

31+ describe moduleName $ do

32+ describe "Repeated Fold" $ do

33+ prop "testgroupsOf" testgroupsOf

test/streamly-tests.cabal+6

@@ -241,6 +241,12 @@ test-suite Data.Array

241241 main-is: Streamly/Test/Data/Array.hs

242242 ghc-options: -main-is Streamly.Test.Data.Array.main

243243

244+test-suite Data.Stream

245+ import: test-options

246+ type: exitcode-stdio-1.0

247+ main-is: Streamly/Test/Data/Stream.hs

248+ ghc-options: -main-is Streamly.Test.Data.Stream.main

249+

244250test-suite Data.Array.Mut

245251 import: test-options

246252 type: exitcode-stdio-1.0