e9a0e7c · streamly · git.iko.soy

git.iko.soy/streamly

Move rmapM to Fold/Types.hs

commite9a0e7c118a1e01bb493f2fb90ec2f7db7d56626 authorHarendra Kumar <harendra@composewell.com> dateWed 10 Mar 2021, 01:40 (6 years ago) parente95d056

5 files changed+25−13

compare with master

unifiedsplit

Changelog.md+3−3 benchmark/Streamly/Benchmark/Data/Fold.hs+1−1 src/Streamly/Data/Fold.hs−1 src/Streamly/Internal/Data/Fold.hs+1−8 src/Streamly/Internal/Data/Fold/Types.hs+20

Changelog.md+3−3

@@ -64,9 +64,9 @@

6464 * `encodeLatin1Lax` to `encodeLatin1`

6565 * `decodeUtf8Lenient` to `decodeUtf8`

6666* Drop support for GHC 7.10.3.

67−* The following functions in `Streamly.Data.Fold` have been renamed:

68− * `mapM` to `rmapM`

69− * `sequence` to `rsequence`

67+* The following functions in `Streamly.Data.Fold` have been deprecated:

68+ * `mapM` is replaced by `rmapM`

69+ * `sequence` is dprecated, please use `rmapM id` instead.

7070

7171### Internal APIs

7272

benchmark/Streamly/Benchmark/Data/Fold.hs+1−1

@@ -260,7 +260,7 @@ o_1_space_serial_transformation value =

260260 , benchIOSink

261261 value

262262 "rsequence"

263− (S.fold (FL.rsequence (return <$> FL.drain)))

263+ (S.fold (FL.rmapM id (return <$> FL.drain)))

264264 , benchIOSink value "rmapM" (S.fold (FL.rmapM return FL.drain))

265265 , benchIOSink

266266 value

src/Streamly/Data/Fold.hs−1

@@ -128,7 +128,6 @@ module Streamly.Data.Fold

128128 --

129129 -- Note: Output transformations are also known as covariant

130130 -- transformations.

131− , rsequence

132131 , sequence

133132 , rmapM

134133 , mapM

src/Streamly/Internal/Data/Fold.hs+1−8

@@ -307,14 +307,7 @@ rsequence (Fold step initial extract) = Fold step' initial1 extract'

307307{-# DEPRECATED sequence "Use rsequence instead" #-}

308308{-# INLINE sequence #-}

309309sequence :: Monad m => Fold m a (m b) -> Fold m a b

310−sequence = rsequence

311−

312−-- | Map a monadic function on the output of a fold.

313−--

314−-- @since 0.8.0

315−{-# INLINE rmapM #-}

316−rmapM :: Monad m => (b -> m c) -> Fold m a b -> Fold m a c

317−rmapM f = sequence . fmap f

310+sequence = rmapM id

318311

319312-- | Map a monadic function on the output of a fold.

320313--

src/Streamly/Internal/Data/Fold/Types.hs+20

@@ -198,6 +198,7 @@ module Streamly.Internal.Data.Fold.Types

198198 , yieldM

199199

200200 -- * Transformations

201+ , rmapM

201202 , map

202203 , lmap

203204 , lmapM

@@ -300,6 +301,13 @@ instance Functor (Step s) where

300301 {-# INLINE fmap #-}

301302 fmap = second

302303

304+{-# INLINE mapMStep #-}

305+mapMStep :: Applicative m => (a -> m b) -> Step s a -> m (Step s b)

306+mapMStep f res =

307+ case res of

308+ Partial s -> pure $ Partial s

309+ Done b -> Done <$> f b

310+

303311-- The Step functor around b allows expressing early termination like a right

304312-- fold. Traditional list right folds use function composition and laziness to

305313-- terminate early whereas we use data constructors. It allows stream fusion in

@@ -326,6 +334,18 @@ data Fold m a b =

326334 -- | @Fold @ @ step @ @ initial @ @ extract@

327335 forall s. Fold (s -> a -> m (Step s b)) (m (Step s b)) (s -> m b)

328336

337+-- | Map a monadic function on the output of a fold.

338+--

339+-- @since 0.8.0

340+{-# INLINE rmapM #-}

341+rmapM :: Monad m => (b -> m c) -> Fold m a b -> Fold m a c

342+rmapM f (Fold step initial extract) = Fold step1 initial1 (extract >=> f)

343+

344+ where

345+

346+ initial1 = initial >>= mapMStep f

347+ step1 s a = step s a >>= mapMStep f

348+

329349------------------------------------------------------------------------------

330350-- Left fold constructors

331351------------------------------------------------------------------------------