Change the signature of Parser.deintercalate, move fold at end (#1904)

benchmark/Streamly/Benchmark/Data/Parser.hs

@@ -199,7 +199,7 @@ deintercalate _ = Stream.parse (partition even)
 
     partition p =
         PR.deintercalate
-            Fold.drain (PR.takeWhile (not . p) Fold.sum) (PR.takeWhile p Fold.sum)
+            (PR.takeWhile (not . p) Fold.sum) (PR.takeWhile p Fold.sum) Fold.drain
 
 {-# INLINE manyWordByEven #-}
 manyWordByEven :: MonadThrow m => Stream m Int -> m ()

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

@@ -1446,14 +1446,14 @@ manyThen _parser _recover _f = undefined
 --
 {-# INLINE deintercalate #-}
 deintercalate :: Monad m =>
-       Fold m (Either x y) z
-    -> Parser m a x
+       Parser m a x
     -> Parser m a y
+    -> Fold m (Either x y) z
     -> Parser m a z
-deintercalate sink contentL contentR =
+deintercalate contentL contentR sink =
     D.toParserK
         $ D.deintercalate
-            sink (D.fromParserK contentL) (D.fromParserK contentR)
+            (D.fromParserK contentL) (D.fromParserK contentR) sink
 
 -- | Parse items separated by a separator parsed by the supplied parser. At
 -- least one item must be present for the parser to succeed.
@@ -1474,7 +1474,7 @@ sepBy1 sink p sep = do
 -- run, when it is done content parser is run again and so on. If none of the
 -- parsers consumes an input then parser returns a failure.
 --
--- >>> sepBy sink = Parser.deintercalate (Fold.lefts sink)
+-- >>> sepBy sink p1 p2 = Parser.deintercalate p1 p2 (Fold.lefts sink)
 -- >>> sepBy sink content sep = Parser.sepBy1 sink content sep <|> return mempty
 --
 {-# INLINE sepBy #-}

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

@@ -1835,14 +1835,14 @@ data DeintercalateState fs sp ss =
 --
 {-# INLINE deintercalate #-}
 deintercalate :: Monad m =>
-       Fold m (Either x y) z
-    -> Parser m a x
+       Parser m a x
     -> Parser m a y
+    -> Fold m (Either x y) z
     -> Parser m a z
 deintercalate
-    (Fold fstep finitial fextract)
     (Parser stepL initialL extractL)
-    (Parser stepR initialR extractR) = Parser step initial extract
+    (Parser stepR initialR extractR)
+    (Fold fstep finitial fextract) = Parser step initial extract
 
     where
 

test/Streamly/Test/Data/Parser.hs

@@ -605,7 +605,7 @@ deintercalate =
             partition =
                 FL.tee (fmap concat $ FL.lefts FL.toList)
                        (fmap concat $ FL.rights FL.toList)
-            p = P.deintercalate partition p1 p2
+            p = P.deintercalate p1 p2 partition
 
 -- shortestPass :: Property
 -- shortestPass =