001    /*
002     * hammurapi-rules-tutorial @mesopotamia.version@
003     * Hammurapi rules tutorial. 
004     * Copyright (C) 2006  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.tutorial.rules;
024    
025    import biz.hammurapi.rules.Rule;
026    import biz.hammurapi.rules.tutorial.conclusions.Husband;
027    import biz.hammurapi.rules.tutorial.conclusions.Spouse;
028    import biz.hammurapi.rules.tutorial.conclusions.Wife;
029    
030    public class SpouseRules extends Rule { 
031                    
032            public SpouseRules() {
033                    setMethodFactTypes(Spouse.class , new Class[] {Husband.class, Wife.class});
034            }
035            
036            /**
037             * Male spouse is husband, female spouse is wife.
038             * If A is a spouse of B then B is a spouse of A. 
039             * @param spouse
040             * @return Brother or Sister.
041             */
042            public Spouse infer(Spouse spouse) {
043                    post(new Spouse(spouse.getObject(), spouse.getSubject()));
044                    
045                    if (spouse.getSubject().isMale()) {
046                            if (!(spouse instanceof Husband)) {
047                                    return new  Husband(spouse.getSubject(), spouse.getObject());
048                            }                       
049                    } else {
050                            if (!(spouse instanceof Wife)) {
051                                    return new Wife(spouse.getSubject(), spouse.getObject());
052                            }                       
053                    }
054                    return null;
055            }
056    }