001package net.sf.cpsolver.coursett.constraint;
002
003import java.util.Set;
004
005import net.sf.cpsolver.coursett.criteria.StudentConflict;
006import net.sf.cpsolver.coursett.model.Lecture;
007import net.sf.cpsolver.coursett.model.Placement;
008import net.sf.cpsolver.ifs.model.Constraint;
009
010/**
011 * Ignore student conflicts constraint. <br>
012 * This constraint keeps track of classes between which student conflicts of any kind are to be ignored.
013 * This constraint is used by {@link Lecture#isToIgnoreStudentConflictsWith(Lecture)} and translates to
014 * {@link StudentConflict#ignore(Lecture, Lecture)} that is true when the two classes are connected by
015 * this constraint.
016 *   
017 * <br>
018 * 
019 * @version CourseTT 1.2 (University Course Timetabling)<br>
020 *          Copyright (C) 2013 Tomáš Müller<br>
021 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
022 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
023 * <br>
024 *          This library is free software; you can redistribute it and/or modify
025 *          it under the terms of the GNU Lesser General Public License as
026 *          published by the Free Software Foundation; either version 3 of the
027 *          License, or (at your option) any later version. <br>
028 * <br>
029 *          This library is distributed in the hope that it will be useful, but
030 *          WITHOUT ANY WARRANTY; without even the implied warranty of
031 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
032 *          Lesser General Public License for more details. <br>
033 * <br>
034 *          You should have received a copy of the GNU Lesser General Public
035 *          License along with this library; if not see
036 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
037 */
038public class IgnoreStudentConflictsConstraint extends Constraint<Lecture, Placement> {
039    
040    public static final String REFERENCE = "NO_CONFLICT";
041    
042    @Override
043    public void addVariable(Lecture variable) {
044        super.addVariable(variable);
045        variable.clearIgnoreStudentConflictsWithCache();
046    }
047
048    @Override
049    public void computeConflicts(Placement value, Set<Placement> conflicts) {
050    }
051    
052    @Override
053    public boolean isHard() {
054        return false;
055    }
056
057}