Support containers-0.8 in traverseMapWithKey.

Author: jonathanknowles

src/Data/IntMap/NonEmpty/Internal.hs

@@ -716,11 +716,19 @@ insertMaxMap = M.insert
 -- | /O(n)/. A fixed version of 'Data.IntMap.traverseWithKey' that
 -- traverses items in ascending order of keys.
 traverseMapWithKey :: Applicative t => (Key -> a -> t b) -> IntMap a -> t (IntMap b)
+#if MIN_VERSION_containers(0,8,0)
+traverseMapWithKey f = go
+  where
+    go Nil = pure Nil
+    go (Tip k v) = Tip k <$> f k v
+    go (Bin p l r) = liftA2 (flip (Bin p)) (go r) (go l)
+#else
 traverseMapWithKey f = go
   where
     go Nil = pure Nil
     go (Tip k v) = Tip k <$> f k v
     go (Bin p m l r) = liftA2 (flip (Bin p m)) (go r) (go l)
+#endif
 {-# INLINE traverseMapWithKey #-}
 
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