1 files changed, 18 insertions, 2 deletions
diff --git a/dynarray.sml b/dynarray.sml
index b052989..371362e 100644
--- a/dynarray.sml
+++ b/dynarray.sml
@@ -17,7 +17,8 @@ structure Dynarray: DYNARRAY = struct
   let
     val (len, arr) = !dynarr
   in
-    if len = Array.length arr then
+    case Int.compare (len, Array.length arr) of
+      EQUAL =>
       let
         val arr2 = Array.array (len * 2, NONE)
       in
@@ -25,9 +26,11 @@ structure Dynarray: DYNARRAY = struct
         dynarr := (len, arr2);
         push dynarr v
       end
-    else
+    | LESS => (
       Array.update (arr, len, SOME v);
       dynarr := (len + 1, arr)
+    )
+    | GREATER => raise Unreachable
   end
 
   fun get dynarr n =
@@ -70,4 +73,17 @@ structure Dynarray: DYNARRAY = struct
   in
     Vector.fromList l
   end
+
+  fun appi f dynarr =
+  let
+    val (len, arr) = !dynarr
+
+    fun loop idx =
+      if idx = len then
+        ()
+      else
+        f (idx, valOf $ Array.sub (arr, idx))
+  in
+    loop 0
+  end
 end