001    package net.sf.cpsolver.ifs.util;
002    
003    import java.util.Collection;
004    import java.util.Enumeration;
005    
006    /** 
007     * An extension of {@link Collection} that support elements() method 
008     * and few others.
009     *
010     * @version
011     * IFS 1.1 (Iterative Forward Search)<br>
012     * Copyright (C) 2006 Tomáš Müller<br>
013     * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
014     * Lazenska 391, 76314 Zlin, Czech Republic<br>
015     * <br>
016     * This library is free software; you can redistribute it and/or
017     * modify it under the terms of the GNU Lesser General Public
018     * License as published by the Free Software Foundation; either
019     * version 2.1 of the License, or (at your option) any later version.
020     * <br><br>
021     * This library is distributed in the hope that it will be useful,
022     * but WITHOUT ANY WARRANTY; without even the implied warranty of
023     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
024     * Lesser General Public License for more details.
025     * <br><br>
026     * You should have received a copy of the GNU Lesser General Public
027     * License along with this library; if not, write to the Free Software
028     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
029     */
030    public interface EnumerableCollection extends Collection {
031        /** Enumerate content */
032        public Enumeration elements();
033        /** Add an element into the collection */
034        public void addElement(Object o);
035        /** Remove element from the collection */
036        public boolean removeElement(Object o);
037        /** First element in the collection */
038        public Object firstElement();
039    }