--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/arrays/ArrayLikeIterator.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,178 @@
+/*
+ * Copyright (c) 2010, 2013, 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.internal.runtime.arrays;
+
+import java.util.Iterator;
+import java.util.List;
+import jdk.nashorn.api.scripting.JSObject;
+import jdk.nashorn.internal.runtime.JSType;
+import jdk.nashorn.internal.runtime.ScriptObject;
+
+/**
+ * Superclass for array iterators
+ * TODO: rewrite these
+ *
+ * @param <T> element type
+ */
+abstract public class ArrayLikeIterator<T> implements Iterator<T> {
+
+    /** current element index in iteration */
+    protected long index;
+
+    /** should undefined elements be included in the iteration? */
+    protected final boolean includeUndefined;
+
+    /**
+     * Constructor
+     *
+     * @param includeUndefined should undefined elements be included in the iteration?
+     */
+    ArrayLikeIterator(final boolean includeUndefined) {
+        this.includeUndefined = includeUndefined;
+        this.index = 0;
+    }
+
+    /**
+     * Is this a reverse order iteration?
+     * @return true if reverse
+     */
+    public boolean isReverse() {
+        return false;
+    }
+
+    /**
+     * Go the the next valid element index of the iterator
+     * @return next index
+     */
+    protected long bumpIndex() {
+        return index++;
+    }
+
+    /**
+     * Return the next valid element index of the iterator
+     * @return next index
+     */
+    public long nextIndex() {
+        return index;
+    }
+
+    @Override
+    public void remove() {
+        throw new UnsupportedOperationException("remove");
+    }
+
+    /**
+     * Get the length of the iteration
+     * @return length
+     */
+    public abstract long getLength();
+
+    /**
+     * ArrayLikeIterator factory
+     *
+     * @param object object over which to do element iteration
+     * @return iterator
+     */
+    public static ArrayLikeIterator<Object> arrayLikeIterator(final Object object) {
+        return arrayLikeIterator(object, false);
+    }
+
+    /**
+     * ArrayLikeIterator factory (reverse order)
+     * @param object object over which to do reverse element iteration
+     * @return iterator
+     */
+    public static ArrayLikeIterator<Object> reverseArrayLikeIterator(final Object object) {
+        return reverseArrayLikeIterator(object, false);
+    }
+
+    /**
+     * ArrayLikeIterator factory
+     * @param object object over which to do reverse element iteration
+     * @param includeUndefined should undefined elements be included in the iteration
+     * @return iterator
+     */
+    public static ArrayLikeIterator<Object> arrayLikeIterator(final Object object, final boolean includeUndefined) {
+        Object obj = object;
+
+        if (ScriptObject.isArray(obj)) {
+            return new ScriptArrayIterator((ScriptObject) obj, includeUndefined);
+        }
+
+        obj = JSType.toScriptObject(obj);
+        if (obj instanceof ScriptObject) {
+            return new ScriptObjectIterator((ScriptObject)obj, includeUndefined);
+        }
+
+        if (obj instanceof JSObject) {
+            return new JSObjectIterator((JSObject)obj, includeUndefined);
+        }
+
+        if (obj instanceof List) {
+            return new JavaListIterator((List<?>)obj, includeUndefined);
+        }
+
+        if (obj != null && obj.getClass().isArray()) {
+            return new JavaArrayIterator(obj, includeUndefined);
+        }
+
+        return new EmptyArrayLikeIterator();
+    }
+
+    /**
+     * ArrayLikeIterator factory (reverse order)
+     * @param object object over which to do reverse element iteration
+     * @param includeUndefined should undefined elements be included in the iteration
+     * @return iterator
+     */
+    public static ArrayLikeIterator<Object> reverseArrayLikeIterator(final Object object, final boolean includeUndefined) {
+        Object obj = object;
+
+        if (ScriptObject.isArray(obj)) {
+            return new ReverseScriptArrayIterator((ScriptObject) obj, includeUndefined);
+        }
+
+        obj = JSType.toScriptObject(obj);
+        if (obj instanceof ScriptObject) {
+            return new ReverseScriptObjectIterator((ScriptObject)obj, includeUndefined);
+        }
+
+        if (obj instanceof JSObject) {
+            return new ReverseJSObjectIterator((JSObject)obj, includeUndefined);
+        }
+
+        if (obj instanceof List) {
+            return new ReverseJavaListIterator((List<?>)obj, includeUndefined);
+        }
+
+        if (obj != null && obj.getClass().isArray()) {
+            return new ReverseJavaArrayIterator(obj, includeUndefined);
+        }
+
+        return new EmptyArrayLikeIterator();
+    }
+
+}