Added Util.isPlainObject().

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4952 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/util/StringUtil.as

@@ -229,7 +229,7 @@ public class StringUtil
             }
             return "Array(" + s + ")";
 
-        } else if (obj.constructor == Object) {
+        } else if (Util.isPlainObject(obj)) {
             // TODO: maybe do this for any dynamic object? (would have to use describeType)
             s = "";
             for (var prop :String in obj) {

src/as/com/threerings/util/Util.as

@@ -23,6 +23,8 @@ package com.threerings.util {
 
 import flash.utils.ByteArray;
 
+import flash.utils.describeType; // function import
+
 public class Util
 {
     /**
@@ -58,6 +60,14 @@ public class Util
         }
     }
 
+    /**
+     * Returns true if the specified object is just a regular old associative hash.
+     */
+    public static function isPlainObject (obj :Object) :Boolean
+    {
+        return (obj != null) && ("Object" == describeType(obj).@name.toString());
+    }
+
     /**
      * Is the specified object 'simple': one of the basic built-in flash types.
      */