/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Rhino code, released
 * May 6, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1997-1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License Version 2 or later (the "GPL"), in which
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package org.mozilla.javascript.regexp;

/**
 * A utility class for lazily instantiated substrings.
 */
public class SubString {

    public SubString()
    {
    }

    public SubString(String str)
    {
        this.str = str;
        index = 0;
        length = str.length();
    }

    public SubString(String source, int start, int len)
    {
        str = source;
        index = start;
        length = len;
    }

    @Override
    public String toString() {
        return str == null
               ? ""
               : str.substring(index, index + length);
    }

    public static final SubString emptySubString = new SubString();

    String str;
    int    index;
    int    length;
}