001    /**
002     * Copyright (C) 2007-2011, Jens Lehmann
003     *
004     * This file is part of DL-Learner.
005     *
006     * DL-Learner is free software; you can redistribute it and/or modify
007     * it under the terms of the GNU General Public License as published by
008     * the Free Software Foundation; either version 3 of the License, or
009     * (at your option) any later version.
010     *
011     * DL-Learner 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
014     * GNU General Public License for more details.
015     *
016     * You should have received a copy of the GNU General Public License
017     * along with this program.  If not, see <http://www.gnu.org/licenses/>.
018     */
019    
020    package org.dllearner.core.owl;
021    
022    import java.net.URI;
023    import java.util.Map;
024    
025    /**
026     * Implementation of owl:thing/TOP.
027     * 
028     * TODO: According to the OWL 1.1 spec, owl:thing is special instance of
029     * class, so it might be better to put a method there for retrieving 
030     * a/the instance of owl:thing. However, some algorithms require parent
031     * links e.g. in EXISTS r.TOP we may need to know where TOP belongs
032     * (especially for genetic operators). This is instance dependant, i.e. 
033     * two different instances of TOP can have different parent links.
034     * 
035     * @author Jens Lehmann
036     *
037     */
038    public class Thing extends Description {
039    
040            /**
041             * 
042             */
043            private static final long serialVersionUID = -880276915058868775L;
044            public static final Thing instance = new Thing();
045            
046            private static final URI uri = URI.create("http://www.w3.org/2002/07/owl#Thing");
047            
048        public String toString(String baseURI, Map<String,String> prefixes) {
049            return "TOP";
050        }
051        
052        public String toKBSyntaxString(String baseURI, Map<String,String> prefixes) {
053            return "TOP";
054        }
055    
056            @Override
057            public String toManchesterSyntaxString(String baseURI, Map<String, String> prefixes) {
058                    // in Protege 3.3 owl:Thing
059                    // in Protege 4.0 only Thing
060                    //return "owl:Thing";
061                    return "Thing";
062                    
063            }         
064            
065            public URI getURI(){
066                    return uri;
067            }
068        
069            public int getLength() {
070                    return 1;
071            }
072    
073            @Override
074            public int getArity() {
075                    return 0;
076            }  
077            
078            /* (non-Javadoc)
079             * @see org.dllearner.core.owl.Description#accept(org.dllearner.core.owl.DescriptionVisitor)
080             */
081            @Override
082            public void accept(DescriptionVisitor visitor) {
083                    visitor.visit(this);
084            }       
085            
086            public void accept(KBElementVisitor visitor) {
087                    visitor.visit(this);
088            }
089    
090    
091    }