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