    001package org.cpsolver.ifs.assignment;
    002
    003import java.util.ArrayList;
    004import java.util.Collection;
    005
    006import org.cpsolver.ifs.assignment.context.AssignmentContextHolderMap;
    007import org.cpsolver.ifs.model.Value;
    008import org.cpsolver.ifs.model.Variable;
    009
    010
    011/**
    012 * An empty assignment. All variables are unassigned, any attempt to assign a
    013 * variable will throw the {@link UnsupportedOperationException} exception.<br><br>
    014 *
    015 * @author  Tomáš Müller
    016 * @version IFS 1.3 (Iterative Forward Search)<br>
    017 *          Copyright (C) 2014 Tomáš Müller<br>
    018 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    019 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    020 * <br>
    021 *          This library is free software; you can redistribute it and/or modify
    022 *          it under the terms of the GNU Lesser General Public License as
    023 *          published by the Free Software Foundation; either version 3 of the
    024 *          License, or (at your option) any later version. <br>
    025 * <br>
    026 *          This library is distributed in the hope that it will be useful, but
    027 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    028 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    029 *          Lesser General Public License for more details. <br>
    030 * <br>
    031 *          You should have received a copy of the GNU Lesser General Public
    032 *          License along with this library; if not see <a href='http://www.gnu.org/licenses'>http://www.gnu.org/licenses</a>.
    033 * @param <V> Variable
    034 * @param <T> Value
    035 **/
    036public class EmptyAssignment<V extends Variable<V, T>, T extends Value<V, T>> extends AssignmentAbstract<V, T> {
    037
    038    public EmptyAssignment() {
    039        super(new AssignmentContextHolderMap<V,T>());
    040    }
    041
    042    @Override
    043    public long getIteration(V variable) {
    044        return 0;
    045    }
    046
    047    @Override
    048    public Collection<V> assignedVariables() {
    049        return new ArrayList<V>();
    050    }
    051
    052    @Override
    053    protected T getValueInternal(V variable) {
    054        return null;
    055    }
    056
    057    @Override
    058    protected void setValueInternal(long iteration, V variable, T value) {
    059        throw new UnsupportedOperationException();
    060    }
    061}