001/** 002 * Copyright (C) 2007 - 2016, 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 */ 019package org.dllearner.algorithms.el; 020 021import java.util.Comparator; 022 023/** 024 * Compares two EL OWLClassExpression trees by calling {@link ELDescriptionNodeComparator} 025 * on their root nodes. 026 * 027 * @author Jens Lehmann 028 * 029 */ 030public class ELDescriptionTreeComparator implements Comparator<ELDescriptionTree> { 031 032 private ELDescriptionNodeComparator nodeComp; 033 034 public ELDescriptionTreeComparator() { 035 nodeComp = new ELDescriptionNodeComparator(); 036 } 037 038 /* (non-Javadoc) 039 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object) 040 */ 041 @Override 042 public int compare(ELDescriptionTree tree1, ELDescriptionTree tree2) { 043 // we use the size as first criterion to avoid many comparisons 044 int sizeDiff = tree1.size - tree2.size; 045 if(sizeDiff == 0) { 046 ELDescriptionNode node1 = tree1.getRootNode(); 047 ELDescriptionNode node2 = tree2.getRootNode(); 048 return nodeComp.compare(node1, node2); 049 } else { 050 return sizeDiff; 051 } 052 } 053 054}