    001package org.cpsolver.ifs.model;
    002
    003import org.cpsolver.ifs.assignment.Assignment;
    004
    005/**
    006 * Interface of a constraint that weakens with the time.
    007 *
    008 * @author  Tomáš Müller
    009 * @version CourseTT 1.3 (University Course Timetabling)<br>
    010 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    011 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    012 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    013 * <br>
    014 *          This library is free software; you can redistribute it and/or modify
    015 *          it under the terms of the GNU Lesser General Public License as
    016 *          published by the Free Software Foundation; either version 3 of the
    017 *          License, or (at your option) any later version. <br>
    018 * <br>
    019 *          This library is distributed in the hope that it will be useful, but
    020 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    021 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    022 *          Lesser General Public License for more details. <br>
    023 * <br>
    024 *          You should have received a copy of the GNU Lesser General Public
    025 *          License along with this library; if not see
    026 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    027 *
    028 * @param <V> Variable
    029 * @param <T> Value
    030 */
    031public interface WeakeningConstraint<V extends Variable<V, T>, T extends Value<V, T>> {
    032    /**
    033     * Weaken the constraint. This method is called if the constraint
    034     * participates in an unassigned of a variable.
    035     * @param assignment current assignment
    036     */
    037    public void weaken(Assignment<V, T> assignment);
    038
    039
    040    /**
    041     * Weaken the constraint enough so that it can assign the given
    042     * value.
    043     * @param assignment current assignment
    044     * @param value a conflicting value to be assigned
    045     */
    046    public void weaken(Assignment<V, T> assignment, T value);
    047}