--- /dev/null	2015-08-17 12:39:40.000000000 +0530
+++ new/src/jdk.scripting.nashorn.shell/share/classes/jdk/nashorn/tools/jjs/PropertiesHelper.java	2015-08-17 12:39:40.403885000 +0530
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.nashorn.tools.jjs;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.WeakHashMap;
+import java.util.stream.Collectors;
+import jdk.nashorn.internal.runtime.JSType;
+import jdk.nashorn.internal.runtime.PropertyMap;
+import jdk.nashorn.internal.runtime.ScriptObject;
+import jdk.nashorn.internal.runtime.ScriptRuntime;
+import jdk.nashorn.internal.objects.NativeJava;
+
+/*
+ * A helper class to get properties of a given object for source code completion.
+ */
+final class PropertiesHelper {
+    private PropertiesHelper() {}
+
+    // cached properties list
+    private static final WeakHashMap<Object, List<String>> propsCache = new WeakHashMap<>();
+
+    // returns the list of properties of the given object
+    static List<String> getProperties(final Object obj) {
+        assert obj != null && obj != ScriptRuntime.UNDEFINED;
+
+        if (JSType.isPrimitive(obj)) {
+            return getProperties(JSType.toScriptObject(obj));
+        }
+
+        if (obj instanceof ScriptObject) {
+            final ScriptObject sobj = (ScriptObject)obj;
+            final PropertyMap pmap = sobj.getMap();
+            if (propsCache.containsKey(pmap)) {
+                return propsCache.get(pmap);
+            }
+            final String[] keys = sobj.getAllKeys();
+            List<String> props = Arrays.asList(keys);
+            props = props.stream()
+                         .filter(s -> Character.isJavaIdentifierStart(s.charAt(0)))
+                         .collect(Collectors.toList());
+            Collections.sort(props);
+            // cache properties against the PropertyMap
+            propsCache.put(pmap, props);
+            return props;
+        }
+
+        if (NativeJava.isType(ScriptRuntime.UNDEFINED, obj)) {
+            if (propsCache.containsKey(obj)) {
+                return propsCache.get(obj);
+            }
+            final List<String> props = NativeJava.getProperties(obj);
+            Collections.sort(props);
+            // cache properties against the StaticClass representing the class
+            propsCache.put(obj, props);
+            return props;
+        }
+
+        final Class<?> clazz = obj.getClass();
+        if (propsCache.containsKey(clazz)) {
+            return propsCache.get(clazz);
+        }
+
+        final List<String> props = NativeJava.getProperties(obj);
+        Collections.sort(props);
+        // cache properties against the Class object
+        propsCache.put(clazz, props);
+        return props;
+    }
+
+    // returns the list of properties of the given object that start with the given prefix
+    static List<String> getProperties(final Object obj, final String prefix) {
+        assert prefix != null && !prefix.isEmpty();
+        return getProperties(obj).stream()
+                   .filter(s -> s.startsWith(prefix))
+                   .collect(Collectors.toList());
+    }
+}