    001package net.sf.cpsolver.ifs.model;
    002
    003/**
    004 * Interface of a constraint that weakens with the time.
    005 *
    006 * @version CourseTT 1.2 (University Course Timetabling)<br>
    007 *          Copyright (C) 2006 - 2010 Tomáš Müller<br>
    008 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    009 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    010 * <br>
    011 *          This library is free software; you can redistribute it and/or modify
    012 *          it under the terms of the GNU Lesser General Public License as
    013 *          published by the Free Software Foundation; either version 3 of the
    014 *          License, or (at your option) any later version. <br>
    015 * <br>
    016 *          This library is distributed in the hope that it will be useful, but
    017 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    018 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    019 *          Lesser General Public License for more details. <br>
    020 * <br>
    021 *          You should have received a copy of the GNU Lesser General Public
    022 *          License along with this library; if not see
    023 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    024 */
    025
    026public interface WeakeningConstraint<V extends Variable<V, T>, T extends Value<V, T>> {
    027    /**
    028     * Weaken the constraint. This method is called if the constraint
    029     * participates in an unassigned of a variable.
    030     */
    031    public void weaken();
    032
    033
    034    /**
    035     * Weaken the constraint enough so that it can assign the given
    036     * value.
    037     */
    038    public void weaken(T value);
    039}