1 /*

     2  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package jdk.nashorn.internal.runtime.arrays;

    27 

    28 import jdk.nashorn.api.scripting.ScriptObjectMirror;

    29 import jdk.nashorn.internal.runtime.JSType;

    30 

    31 /**

    32  * Reverse iterator over a ScriptObjectMirror

    33  */

    34 final class ReverseScriptObjectMirrorIterator extends ScriptObjectMirrorIterator {

    35 

    36     ReverseScriptObjectMirrorIterator(final ScriptObjectMirror obj, final boolean includeUndefined) {

    37         super(obj, includeUndefined);

    38         this.index = JSType.toUint32(obj.containsKey("length")? obj.getMember("length") : 0) - 1;

    39     }

    40 

    41     @Override

    42     public boolean isReverse() {

    43         return true;

    44     }

    45 

    46     @Override

    47     protected boolean indexInArray() {

    48         return index >= 0;

    49     }

    50 

    51     @Override

    52     protected long bumpIndex() {

    53         return index--;

    54     }

    55 }

    56