9eedc70 · streamly · git.iko.soy

git.iko.soy/streamly

impl StreamD versions of max/min and optimize StreamK versions

commit9eedc703851ef1ec8c20601a6edbabde4766b524 authorHarendra Kumar <harendra.kumar@gmail.com> dateTue 26 Jun 2018, 19:43 (8 years ago) parentc7d2f9e

3 files changed+93−30

compare with master

unifiedsplit

src/Streamly/Prelude.hs+6−28 src/Streamly/Streams/StreamD.hs+39−1 src/Streamly/Streams/StreamK.hs+48−1

src/Streamly/Prelude.hs+6−28

@@ -89,15 +89,15 @@ module Streamly.Prelude

8989 , foldxM

9090

9191 -- ** Specialized Folds

92− , all

93− , any

92+ , null

9493 , head

9594 , tail

9695 , last

97− , null

98− , length

9996 , elem

10097 , notElem

98+ , length

99+ , all

100+ , any

101101 , maximum

102102 , minimum

103103 , sum

@@ -591,41 +591,19 @@ notElem e m = go (toStream m)

591591length :: Monad m => SerialT m a -> m Int

592592length = foldl' (\n _ -> n + 1) 0

593593

594−-- XXX replace the recursive "go" with continuation

595594-- | Determine the minimum element in a stream.

596595--

597596-- @since 0.1.0

598597{-# INLINE minimum #-}

599598minimum :: (Monad m, Ord a) => SerialT m a -> m (Maybe a)

600−minimum m = go Nothing (toStream m)

601− where

602− go res m1 =

603− let stop = return res

604− single a = return $ min_ a res

605− yieldk a r = go (min_ a res) r

606− in (K.unStream m1) Nothing stop single yieldk

607−

608− min_ a res = case res of

609− Nothing -> Just a

610− Just e -> Just $ min a e

599+minimum m = S.minimum (toStreamS m)

611600

612−-- XXX replace the recursive "go" with continuation

613601-- | Determine the maximum element in a stream.

614602--

615603-- @since 0.1.0

616604{-# INLINE maximum #-}

617605maximum :: (Monad m, Ord a) => SerialT m a -> m (Maybe a)

618−maximum m = go Nothing (toStream m)

619− where

620− go res m1 =

621− let stop = return res

622− single a = return $ max_ a res

623− yieldk a r = go (max_ a res) r

624− in (K.unStream m1) Nothing stop single yieldk

625−

626− max_ a res = case res of

627− Nothing -> Just a

628− Just e -> Just $ max a e

606+maximum m = S.maximum (toStreamS m)

629607

630608------------------------------------------------------------------------------

631609-- Map and Fold

src/Streamly/Streams/StreamD.hs+39−1

@@ -75,6 +75,8 @@ module Streamly.Streams.StreamD

7575 -- ** Specialized Folds

7676 , runStream

7777 , last

78+ , maximum

79+ , minimum

7880

7981 -- ** Map and Fold

8082 , mapM_

@@ -112,7 +114,7 @@ import Data.Maybe (fromJust, isJust)

112114import GHC.Types ( SPEC(..) )

113115import Prelude

114116 hiding (map, mapM, mapM_, repeat, foldr, last, take, filter,

115− takeWhile, drop, dropWhile)

117+ takeWhile, drop, dropWhile, maximum, minimum)

116118

117119import Streamly.SVar (MonadAsync)

118120import qualified Streamly.Streams.StreamK as K

@@ -308,6 +310,42 @@ runStream (Stream step state) = go SPEC state

308310last :: Monad m => Stream m a -> m (Maybe a)

309311last = foldl' (\_ y -> Just y) Nothing

310312

313+{-# INLINE_NORMAL maximum #-}

314+maximum :: (Monad m, Ord a) => Stream m a -> m (Maybe a)

315+maximum (Stream step state) = go Nothing state

316+ where

317+ go Nothing st = do

318+ r <- step st

319+ case r of

320+ Yield x s -> go (Just x) s

321+ Stop -> return Nothing

322+ go (Just acc) st = do

323+ r <- step st

324+ case r of

325+ Yield x s ->

326+ if acc <= x

327+ then go (Just x) s

328+ else go (Just acc) s

329+ Stop -> return (Just acc)

330+

331+{-# INLINE_NORMAL minimum #-}

332+minimum :: (Monad m, Ord a) => Stream m a -> m (Maybe a)

333+minimum (Stream step state) = go Nothing state

334+ where

335+ go Nothing st = do

336+ r <- step st

337+ case r of

338+ Yield x s -> go (Just x) s

339+ Stop -> return Nothing

340+ go (Just acc) st = do

341+ r <- step st

342+ case r of

343+ Yield x s ->

344+ if acc <= x

345+ then go (Just acc) s

346+ else go (Just x) s

347+ Stop -> return (Just acc)

348+

311349------------------------------------------------------------------------------

312350-- Map and Fold

313351------------------------------------------------------------------------------

src/Streamly/Streams/StreamK.hs+48−1

@@ -78,6 +78,8 @@ module Streamly.Streams.StreamK

7878 , all

7979 , any

8080 , last

81+ , minimum

82+ , maximum

8183

8284 -- ** Map and Fold

8385 , mapM_

@@ -126,7 +128,8 @@ import Control.Monad.Trans.Class (MonadTrans(lift))

126128import Data.Semigroup (Semigroup(..))

127129import Prelude

128130 hiding (foldl, foldr, last, map, mapM, mapM_, repeat, sequence,

129− take, filter, all, any, takeWhile, drop, dropWhile)

131+ take, filter, all, any, takeWhile, drop, dropWhile, minimum,

132+ maximum)

130133import qualified Prelude

131134

132135import Streamly.SVar

@@ -543,6 +546,50 @@ any p m = go (toStream m)

543546last :: (IsStream t, Monad m) => t m a -> m (Maybe a)

544547last = foldx (\_ y -> Just y) Nothing id

545548

549+{-# INLINE minimum #-}

550+minimum :: (IsStream t, Monad m, Ord a) => t m a -> m (Maybe a)

551+minimum m = go Nothing (toStream m)

552+ where

553+ go Nothing m1 =

554+ let stop = return Nothing

555+ single a = return (Just a)

556+ yieldk a r = go (Just a) r

557+ in unStream m1 Nothing stop single yieldk

558+

559+ go (Just res) m1 =

560+ let stop = return (Just res)

561+ single a =

562+ if res <= a

563+ then return (Just res)

564+ else return (Just a)

565+ yieldk a r =

566+ if res <= a

567+ then go (Just res) r

568+ else go (Just a) r

569+ in unStream m1 Nothing stop single yieldk

570+

571+{-# INLINE maximum #-}

572+maximum :: (IsStream t, Monad m, Ord a) => t m a -> m (Maybe a)

573+maximum m = go Nothing (toStream m)

574+ where

575+ go Nothing m1 =

576+ let stop = return Nothing

577+ single a = return (Just a)

578+ yieldk a r = go (Just a) r

579+ in unStream m1 Nothing stop single yieldk

580+

581+ go (Just res) m1 =

582+ let stop = return (Just res)

583+ single a =

584+ if res <= a

585+ then return (Just a)

586+ else return (Just res)

587+ yieldk a r =

588+ if res <= a

589+ then go (Just a) r

590+ else go (Just res) r

591+ in unStream m1 Nothing stop single yieldk

592+

546593------------------------------------------------------------------------------

547594-- Map and Fold

548595------------------------------------------------------------------------------