Rename concatMapDivK to concatMapHeadK

src/Streamly/Internal/Data/Stream/Concurrent.hs

@@ -262,22 +262,23 @@ parTwo modifier stream1 stream2 =
 -- Evaluator
 -------------------------------------------------------------------------------
 
--- | @concatMapDivK useTail useHead stream@, divides the stream in head and
--- tail, maps a stream generator on the head and maps an action on the tail of
--- a stream. Returns the stream generated by the head.
+-- | @concatMapHeadK consumeTail mapHead stream@, maps a stream generation
+-- function on the head element and performs a side effect on the tail.
 --
--- Used for concurrent evaluation of streams using a Channel.
-{-# INLINE concatMapDivK #-}
-concatMapDivK :: Monad m =>
+-- Used for concurrent evaluation of streams using a Channel. A worker
+-- evaluating the stream would queue the tail and go on to evaluate the head.
+-- The tail is picked up by another worker which does the same.
+{-# INLINE concatMapHeadK #-}
+concatMapHeadK :: Monad m =>
        (K.StreamK m a -> m ()) -- ^ Queue the tail
     -> (a -> K.StreamK m b) -- ^ Generate a stream from the head
     -> K.StreamK m a
     -> K.StreamK m b
-concatMapDivK useTail useHead stream =
+concatMapHeadK consumeTail mapHead stream =
     K.mkStream $ \st yld sng stp -> do
         let foldShared = K.foldStreamShared st yld sng stp
-            single a = foldShared $ useHead a
-            yieldk a r = useTail r >> single a
+            single a = foldShared $ mapHead a
+            yieldk a r = consumeTail r >> single a
          in K.foldStreamShared (adaptState st) yieldk single stp stream
 
 -------------------------------------------------------------------------------
@@ -338,7 +339,7 @@ mkEnqueue chan runner = do
 parConcatMapChanK :: MonadAsync m =>
     Channel m b -> (a -> K.StreamK m b) -> K.StreamK m a -> K.StreamK m b
 parConcatMapChanK chan f stream =
-   let run q = concatMapDivK q f
+   let run q = concatMapHeadK q f
     in K.concatMapEffect (`run` stream) (mkEnqueue chan run)
     -- K.parConcatMap (_appendWithChanK chan) f stream
 
@@ -347,7 +348,7 @@ parConcatMapChanKAny :: MonadAsync m =>
     Channel m b -> (a -> K.StreamK m b) -> K.StreamK m a -> K.StreamK m b
 parConcatMapChanKAny chan f stream =
    let done = K.nilM (shutdown chan)
-       run q = concatMapDivK q (\x -> K.append (f x) done)
+       run q = concatMapHeadK q (\x -> K.append (f x) done)
     in K.concatMapEffect (`run` stream) (mkEnqueue chan run)
 
 {-# INLINE parConcatMapChanKFirst #-}
@@ -355,7 +356,7 @@ parConcatMapChanKFirst :: MonadAsync m =>
     Channel m b -> (a -> K.StreamK m b) -> K.StreamK m a -> K.StreamK m b
 parConcatMapChanKFirst chan f stream =
    let done = K.nilM (shutdown chan)
-       run q = concatMapDivK q f
+       run q = concatMapHeadK q f
     in K.concatEffect $ do
         res <- K.uncons stream
         case res of