001package org.cpsolver.coursett.constraint;
002
003import java.util.Set;
004
005import org.cpsolver.coursett.criteria.StudentConflict;
006import org.cpsolver.coursett.model.Lecture;
007import org.cpsolver.coursett.model.Placement;
008import org.cpsolver.ifs.assignment.Assignment;
009import org.cpsolver.ifs.model.Constraint;
010
011
012/**
013 * Ignore student conflicts constraint. <br>
014 * This constraint keeps track of classes between which student conflicts of any kind are to be ignored.
015 * This constraint is used by {@link Lecture#isToIgnoreStudentConflictsWith(Lecture)} and translates to
016 * {@link StudentConflict#ignore(Lecture, Lecture)} that is true when the two classes are connected by
017 * this constraint.
018 *   
019 * <br>
020 * 
021 * @author  Tomáš Müller
022 * @version CourseTT 1.3 (University Course Timetabling)<br>
023 *          Copyright (C) 2013 - 2014 Tomáš Müller<br>
024 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
025 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
026 * <br>
027 *          This library is free software; you can redistribute it and/or modify
028 *          it under the terms of the GNU Lesser General Public License as
029 *          published by the Free Software Foundation; either version 3 of the
030 *          License, or (at your option) any later version. <br>
031 * <br>
032 *          This library is distributed in the hope that it will be useful, but
033 *          WITHOUT ANY WARRANTY; without even the implied warranty of
034 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
035 *          Lesser General Public License for more details. <br>
036 * <br>
037 *          You should have received a copy of the GNU Lesser General Public
038 *          License along with this library; if not see
039 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
040 */
041public class IgnoreStudentConflictsConstraint extends Constraint<Lecture, Placement> {
042    
043    public static final String REFERENCE = "NO_CONFLICT";
044    
045    @Override
046    public void addVariable(Lecture variable) {
047        super.addVariable(variable);
048        variable.clearIgnoreStudentConflictsWithCache();
049    }
050
051    @Override
052    public void computeConflicts(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts) {
053    }
054    
055    @Override
056    public boolean isHard() {
057        return false;
058    }
059
060}