add array of nested objects with guaranteed order

index.d.ts

@@ -732,6 +732,7 @@ export abstract class NamespaceBase extends ReflectionObject {
 
     /** Nested objects of this namespace as an array for iteration. */
     public readonly nestedArray: ReflectionObject[];
+    public readonly orderedNestedMessages: ReflectionObject[];
 
     /**
      * Converts this namespace to a namespace descriptor.

src/namespace.js

@@ -108,6 +108,12 @@ function Namespace(name, options) {
      * @private
      */
     this._nestedArray = null;
+
+    /**
+     * Array of nested messages in the order they were parsed from the schema.
+     * @type {ReflectionObject[]}
+     */
+    this.orderedNestedMessages = null;
 }
 
 function clearCache(namespace) {
@@ -239,6 +245,7 @@ Namespace.prototype.add = function add(object) {
                 throw Error("duplicate name '" + object.name + "' in " + this);
         }
     }
+
     this.nested[object.name] = object;
     object.onAdd(this);
     return clearCache(this);

src/root.js

@@ -306,12 +306,18 @@ Root.prototype._handleAdd = function _handleAdd(object) {
 
     } else if (!(object instanceof OneOf)) /* everything else is a namespace */ {
 
-        if (object instanceof Type) // Try to handle any deferred extensions
+        if (object instanceof Type) { // Try to handle any deferred extensions
+            if (!object.parent.orderedNestedMessages) {
+              object.parent.orderedNestedMessages = [];
+            }
+            object.parent.orderedNestedMessages.push(object);
+
             for (var i = 0; i < this.deferred.length;)
                 if (tryHandleExtension(this, this.deferred[i]))
                     this.deferred.splice(i, 1);
                 else
                     ++i;
+        }
         for (var j = 0; j < /* initializes */ object.nestedArray.length; ++j) // recurse into the namespace
             this._handleAdd(object._nestedArray[j]);
         if (exposeRe.test(object.name))