    001package org.cpsolver.ifs.model;
    002
    003import java.util.Map;
    004
    005import org.cpsolver.ifs.assignment.Assignment;
    006
    007
    008/**
    009 * IFS neighbour.
    010 *
    011 * @see org.cpsolver.ifs.heuristics.NeighbourSelection
    012 *
    013 * @author  Tomáš Müller
    014 * @version IFS 1.3 (Iterative Forward Search)<br>
    015 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    016 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    017 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    018 * <br>
    019 *          This library is free software; you can redistribute it and/or modify
    020 *          it under the terms of the GNU Lesser General Public License as
    021 *          published by the Free Software Foundation; either version 3 of the
    022 *          License, or (at your option) any later version. <br>
    023 * <br>
    024 *          This library is distributed in the hope that it will be useful, but
    025 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    026 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    027 *          Lesser General Public License for more details. <br>
    028 * <br>
    029 *          You should have received a copy of the GNU Lesser General Public
    030 *          License along with this library; if not see
    031 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    032 *
    033 * @param <V> Variable
    034 * @param <T> Value
    035 */
    036public interface Neighbour<V extends Variable<V, T>, T extends Value<V, T>> {
    037    /** Perform assignment
    038     * @param assignment current assignment
    039     * @param iteration current iteration
    040     **/
    041    public void assign(Assignment<V, T> assignment, long iteration);
    042
    043    /** Difference in the evaluation function, if this neighnour is assigned.
    044     * @param assignment current assignment
    045     * @return difference in the solution value when assigned
    046     **/
    047    public double value(Assignment<V, T> assignment);
    048
    049    /** Return assignments to be done.
    050     * @return list of assignments (including unassignments) of this neighbour
    051     **/
    052    public Map<V, T> assignments();
    053}