wip: explore removing delays(8)

src/Pipes.Node.Stream.purs

@@ -13,6 +13,7 @@ import Data.Tuple.Nested ((/\))
 import Effect.Aff.Class (class MonadAff, liftAff)
 import Effect.Class (liftEffect)
 import Effect.Exception (Error)
+import Node.Stream.Object (needsDrain)
 import Node.Stream.Object as O
 import Pipes (await, yield)
 import Pipes (for) as P
@@ -108,7 +109,12 @@ fromTransform t =
       err <- liftEffect $ liftST $ STRef.read error
       for_ err throwError
 
+      needsDrain <- liftEffect $ O.needsDrain t
+      if needsDrain then do
+        liftAff $ O.awaitReadableOrClosed t
         yieldWhileReadable
+        pure $ Loop {error, cancel}
+      else do
         ma <- await
         case ma of
           Nothing -> cleanup cancel
@@ -120,10 +126,7 @@ fromTransform t =
                 maybeYield1
                 pure $ Loop { error, cancel }
               O.WriteWouldBlock -> do
-              queueLen <- liftEffect $ O.readableLength t
-              when (queueLen == 0) $ liftAff $ O.awaitReadableOrClosed t
                 yieldWhileReadable
-              liftAff $ O.awaitWritableOrClosed t
                 pure $ Loop { error, cancel }
   in
     do