001    /*
002     * hammurapi-rules @mesopotamia.version@
003     * Hammurapi rules engine. 
004     * Copyright (C) 2005  Hammurapi Group
005     *
006     * This program is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 2 of the License, or (at your option) any later version.
010     *
011     * This program is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with this library; if not, write to the Free Software
018     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
019     *
020     * URL: http://http://www.hammurapi.biz
021     * e-Mail: support@hammurapi.biz
022     */
023    package biz.hammurapi.rules;
024    
025    /**
026     * Instances of this class represent actions performed by the engine
027     * in response to adding an object to working memory.
028     * Instances of this interface are used during removal process to undo
029     * conclusions.
030     * @author Pavel Vlasov
031     * @revision $Revision$
032     */
033    public interface Action {
034            
035            /**
036             * This method is invoked by ActionTracer when an object
037             * is removed from the working memory.
038             */
039            void undo();
040    }