    001package org.cpsolver.ifs.assignment.context;
    002
    003import org.cpsolver.ifs.assignment.Assignment;
    004import org.cpsolver.ifs.model.Model;
    005import org.cpsolver.ifs.model.Value;
    006import org.cpsolver.ifs.model.Variable;
    007
    008/**
    009 * An interface holding all assignment contexts associated with one assignment. It also
    010 * creates a new assignment context when there is no assignment context associated with the given
    011 * reference.<br><br>
    012 *
    013 * Method {@link AssignmentContextReference#getIndex()} can be used to index stored contexts.
    014 * A new assignment context can be created for a reference by calling {@link HasAssignmentContext#createAssignmentContext(Assignment)}
    015 * on the {@link AssignmentContextReference#getParent()}.
    016 *
    017 * @see AssignmentContext
    018 * @see AssignmentContextReference
    019 * @see HasAssignmentContext
    020 *
    021 * @version IFS 1.3 (Iterative Forward Search)<br>
    022 *          Copyright (C) 2014 Tomáš Müller<br>
    023 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    024 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    025 * <br>
    026 *          This library is free software; you can redistribute it and/or modify
    027 *          it under the terms of the GNU Lesser General Public License as
    028 *          published by the Free Software Foundation; either version 3 of the
    029 *          License, or (at your option) any later version. <br>
    030 * <br>
    031 *          This library is distributed in the hope that it will be useful, but
    032 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    033 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    034 *          Lesser General Public License for more details. <br>
    035 * <br>
    036 *          You should have received a copy of the GNU Lesser General Public
    037 *          License along with this library; if not see <a href='http://www.gnu.org/licenses'>http://www.gnu.org/licenses</a>.
    038 * @param <V> Variable
    039 * @param <T> Value
    040 **/
    041public interface AssignmentContextHolder<V extends Variable<V, T>, T extends Value<V, T>> {
    042
    043    /**
    044     * Return assignment context for the given assignment and reference. A new assignment context is created
    045     * when there is not assignment context associated with the given reference yet.
    046     * @param assignment current assignment (there is only one assignment associated with one holder, but
    047     * the assignment is passed so that {@link HasAssignmentContext#createAssignmentContext(Assignment)} can be called if needed
    048     * @param reference a reference created by calling {@link Model#createReference(HasAssignmentContext)}
    049     * @param <U> assignment context type
    050     * @return an assignment context
    051     */
    052    public <U extends AssignmentContext> U getAssignmentContext(Assignment<V, T> assignment, AssignmentContextReference<V, T, U> reference);
    053
    054    /**
    055     * Clear an assignment context that is associated with the given a reference. If there is any created for the reference.
    056     * @param reference a reference (which can be stored within the model, e.g., as an instance variable of a constraint)
    057     * @param <U> assignment context type
    058     **/
    059    public <U extends AssignmentContext> void clearContext(AssignmentContextReference<V, T, U> reference);
    060
    061}