src/jdk/nashorn/internal/runtime/arrays/JSObjectIterator.java

/*
 * 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
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package jdk.nashorn.internal.runtime.arrays;

import java.util.NoSuchElementException;
import jdk.nashorn.api.scripting.JSObject;
import jdk.nashorn.internal.runtime.JSType;

/**
 * Iterator over a ScriptObjectMirror
 */
class JSObjectIterator extends ArrayLikeIterator<Object> {

    protected final JSObject obj;
    private final long length;

    JSObjectIterator(final JSObject obj, final boolean includeUndefined) {
        super(includeUndefined);
        this.obj    = obj;
        this.length = JSType.toUint32(obj.hasMember("length")? obj.getMember("length") : 0);
        this.index  = 0;
    }

    protected boolean indexInArray() {
        return index < length;
    }

    @Override
    public long getLength() {
        return length;
    }

    @Override
    public boolean hasNext() {
        if (length == 0L) {
            return false; //return empty string if toUint32(length) == 0
        }

        while (indexInArray()) {
            if (obj.hasSlot((int)index) || includeUndefined) {
                break;
            }
            bumpIndex();
        }

        return indexInArray();
    }

    @Override
    public Object next() {
        if (indexInArray()) {
            return obj.getSlot((int)bumpIndex());
        }

        throw new NoSuchElementException();
    }
}