cfafb12 · streamly · git.iko.soy

git.iko.soy/streamly

Add foldlM1' to Data.Fold

commitcfafb121af6075e2b017101342a21ddafb830817 authorHarendra Kumar <harendra@composewell.com> dateMon 6 Mar 2023, 12:08 (4 years ago) parent9e23d29

3 files changed+15

compare with master

unifiedsplit

core/src/Streamly/Data/Fold.hs+1 core/src/Streamly/Internal/Data/Fold.hs+1 core/src/Streamly/Internal/Data/Fold/Type.hs+13

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

@@ -137,6 +137,7 @@ module Streamly.Data.Fold

137137 , foldl'

138138 , foldlM'

139139 , foldl1'

140+ , foldlM1'

140141 , foldr'

141142

142143 -- * Folds

core/src/Streamly/Internal/Data/Fold.hs+1

@@ -31,6 +31,7 @@ module Streamly.Internal.Data.Fold

3131 , foldl'

3232 , foldlM'

3333 , foldl1'

34+ , foldlM1'

3435 , foldt'

3536 , foldtM'

3637 , foldr'

core/src/Streamly/Internal/Data/Fold/Type.hs+13

@@ -335,6 +335,7 @@ module Streamly.Internal.Data.Fold.Type

335335 , foldl'

336336 , foldlM'

337337 , foldl1'

338+ , foldlM1'

338339 , foldt'

339340 , foldtM'

340341 , foldr'

@@ -550,6 +551,18 @@ foldl1' step = fmap toMaybe $ foldl' step1 Nothing'

550551 step1 Nothing' a = Just' a

551552 step1 (Just' x) a = Just' $ step x a

552553

554+-- | Like 'foldl1\'' but with a monadic step function.

555+--

556+-- /Pre-release/

557+{-# INLINE foldlM1' #-}

558+foldlM1' :: Monad m => (a -> a -> m a) -> Fold m a (Maybe a)

559+foldlM1' step = fmap toMaybe $ foldlM' step1 (return Nothing')

560+

561+ where

562+

563+ step1 Nothing' a = return $ Just' a

564+ step1 (Just' x) a = Just' <$> step x a

565+

553566------------------------------------------------------------------------------

554567-- Right fold constructors

555568------------------------------------------------------------------------------