add 'env' parameter to gap_map.sml's mapper

src/gap_map.sml

@@ -69,16 +69,16 @@ struct
     , rightVals: Pair.value vector list
     }
 
-  fun mapList (hd :: tl, acc) =
-        let val hd = Vector.map Map.map hd
+  fun mapList (hd :: tl, acc, env) =
+        let val hd = Vector.map (fn el => Map.map (el, env)) hd
         in mapList (tl, hd :: acc)
         end
-    | mapList ([], acc) = List.rev acc
+    | mapList ([], acc, env) = List.rev acc
 
-  fun map ({leftKeys, leftVals, rightKeys, rightVals}: t) : t =
+  fun map ({leftKeys, leftVals, rightKeys, rightVals}: t, env) : t =
     let
-      val leftVals = mapList (leftVals, [])
-      val rightVals = mapList (rightVals, [])
+      val leftVals = mapList (leftVals, [], env)
+      val rightVals = mapList (rightVals, [], env)
     in
       { leftKeys = leftKeys
       , leftVals = leftVals
@@ -943,9 +943,7 @@ struct
             removeRight (toRemove, leftKeys, leftVals, rightKeys, rightVals)
         end
     | _ => removeLeft (toRemove, leftKeys, leftVals, rightKeys, rightVals)
-end
-
-(* example usage of functor to map over GapMap:
+end (* example usage of functor to map over GapMap:
     structure Pair =
     struct
       type key = int