001    /*
002     * Jpkg - Java library and tools for operating system package creation.
003     *
004     * Copyright (c) 2007-2008 Three Rings Design, Inc.
005     * All rights reserved.
006     *
007     * Redistribution and use in source and binary forms, with or without
008     * modification, are permitted provided that the following conditions
009     * are met:
010     * 1. Redistributions of source code must retain the above copyright
011     *    notice, this list of conditions and the following disclaimer.
012     * 2. Redistributions in binary form must reproduce the above copyright
013     *    notice, this list of conditions and the following disclaimer in the
014     *    documentation and/or other materials provided with the distribution.
015     * 3. Neither the name of the copyright owner nor the names of contributors
016     *    may be used to endorse or promote products derived from this software
017     *    without specific prior written permission.
018     *
019     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
020     * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
021     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
022     * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
023     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
024     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
025     * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
026     * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
027     * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
028     * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
029     * POSSIBILITY OF SUCH DAMAGE.
030     */
031    package com.threerings.antidote;
032    
033    /**
034     * An Ant data type or task whose data is mutable, e.g. may be null.
035     */
036    public interface Mutable
037    {
038        /**
039         * Returns true if the {@link Mutable} data contained in this object is set, e.g. not null.
040         * False otherwise.
041         */
042        public boolean isSet ();
043    
044        /**
045         * Returns true if the {@link Mutable} data contained in this object is not set, e.g. null.
046         * False otherwise.
047         */
048        public boolean isNotSet ();
049    
050    }