@@ -139,6 +139,7 @@ import GHC.Types (SPEC(..))
139139import Prelude
140140 hiding (concat, map, mapM, takeWhile, take, filter, const, zipWith)
141141
142+import Fusion.Plugin.Types (Fuse(..))
142143import Streamly.Internal.Data.Stream.StreamD.Type (Stream(..), Step(..))
143144#if __GLASGOW_HASKELL__ < 800
144145import Streamly.Internal.Data.Stream.StreamD.Type (pattern Stream)
@@ -621,6 +622,7 @@ teeZipWith f unf1 unf2 = lmap (\x -> (x,x)) $ zipWith f unf1 unf2
621622-- Nested
622623-------------------------------------------------------------------------------
623624
625+{-# ANN type ConcatState Fuse #-}
624626data ConcatState s1 s2 = ConcatOuter s1 | ConcatInner s1 s2
625627
626628-- | Apply the second unfold to each output element of the first unfold and