wip

Author: matthewleon

src/Data/Map.purs

@@ -99,7 +99,13 @@ instance functorWithIndexMap :: FunctorWithIndex k (Map k) where
   mapWithIndex f (Three left k1 v1 mid k2 v2 right) = Three (mapWithIndex f left) k1 (f k1 v1) (mapWithIndex f mid) k2 (f k2 v2) (mapWithIndex f right)
 
 instance foldableMap :: Foldable (Map k) where
-  foldl   f z m = foldl   f z (values m)
+  foldl f z m = go acc (m : Nil)
+    go acc Nil = acc
+    go acc (hd : tl) = case hd of
+      Leaf -> go acc tl
+      Two left _ v right ->
+         go (f acc k) (left : right : tl)
+
   foldr   f z m = foldr   f z (values m)
   foldMap f   m = foldMap f   (values m)