Rename: ltakeWhile -> takeSepBy & drainWhile -> drainSepBy

src/Streamly/Internal/Data/Fold.hs

@@ -70,7 +70,7 @@ module Streamly.Internal.Data.Fold
 
     -- ** Partial Folds
     , drainN
-    , drainWhile
+    , drainSepBy
     -- , lastN
     -- , (!!)
     -- , genericIndex
@@ -131,7 +131,7 @@ module Streamly.Internal.Data.Fold
     -- ** Trimming
     , ltake
     -- , lrunFor -- time
-    , ltakeWhile
+    , takeSepBy
     {-
     , ltakeWhileM
     , ldrop
@@ -818,9 +818,9 @@ drainN n = ltake n drain
 
 -- | A fold that drains elements of its input as long as the predicate succeeds,
 -- running the effects and discarding the results.
-{-# INLINABLE drainWhile #-}
-drainWhile :: Monad m => (a -> Bool) -> Fold m a ()
-drainWhile p = ltakeWhile p drain
+{-# INLINABLE drainSepBy #-}
+drainSepBy :: Monad m => (a -> Bool) -> Fold m a ()
+drainSepBy p = takeSepBy p drain
 
 ------------------------------------------------------------------------------
 -- To Elements

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

@@ -132,7 +132,7 @@ module Streamly.Internal.Data.Fold.Types
     , lfilterM
     , lcatMaybes
     , ltake
-    , ltakeWhile
+    , takeSepBy
 
     , teeWith
     , teeWithFst
@@ -587,10 +587,9 @@ ltake n (Fold fstep finitial fextract) = Fold step initial extract
 -- | Takes elements from the input as long as the predicate succeeds.
 --
 -- @since 0.7.0
-{-# INLINE ltakeWhile #-}
-ltakeWhile :: Monad m => (a -> Bool) -> Fold m a b -> Fold m a b
-ltakeWhile predicate (Fold fstep finitial fextract) =
-    Fold step finitial fextract
+{-# INLINE takeSepBy #-}
+takeSepBy :: Monad m => (a -> Bool) -> Fold m a b -> Fold m a b
+takeSepBy predicate (Fold fstep finitial fextract) = Fold step finitial fextract
 
     where
 

src/Streamly/Internal/Data/Parser/ParserD.hs

@@ -384,7 +384,23 @@ takeGE cnt (Fold fstep finitial fextract) = Parser step initial extract
 --
 {-# INLINE takeWhile #-}
 takeWhile :: Monad m => (a -> Bool) -> Fold m a b -> Parser m a b
-takeWhile predicate fld = fromFold (FL.ltakeWhile predicate fld)
+takeWhile predicate (Fold fstep finitial fextract) =
+    Parser step initial fextract
+
+    where
+
+    initial = finitial
+
+    step s a =
+        if predicate a
+        then do
+            fres <- fstep s a
+            return
+                $ case fres of
+                      FL.Partial s1 -> Partial 0 s1
+                      FL.Done b -> Done 0 b
+        else Done 1 <$> fextract s
+
 
 -- | See 'Streamly.Internal.Data.Parser.takeWhile1'.
 --