1 files changed, 9 insertions, 1 deletions
diff --git a/dynarray.sml b/dynarray.sml
index 371362e..d52f148 100644
--- a/dynarray.sml
+++ b/dynarray.sml
@@ -20,7 +20,7 @@ structure Dynarray: DYNARRAY = struct
     case Int.compare (len, Array.length arr) of
       EQUAL =>
       let
-        val arr2 = Array.array (len * 2, NONE)
+        val arr2 = Array.array (len * 2 + 1, NONE)
       in
         Array.copy { src = arr, dst = arr2, di = 0 };
         dynarr := (len, arr2);
@@ -33,6 +33,14 @@ structure Dynarray: DYNARRAY = struct
     | GREATER => raise Unreachable
   end
 
+  fun pushAndGetId dynarr v =
+  let
+    val (len, _ ) = !dynarr
+    val () = push dynarr v
+  in
+    len
+  end
+
   fun get dynarr n =
   let
     val (len, arr) = !dynarr