001/* Copyright (C) 2013 TU Dortmund 002 * This file is part of AutomataLib, http://www.automatalib.net/. 003 * 004 * AutomataLib is free software; you can redistribute it and/or 005 * modify it under the terms of the GNU Lesser General Public 006 * License version 3.0 as published by the Free Software Foundation. 007 * 008 * AutomataLib is distributed in the hope that it will be useful, 009 * but WITHOUT ANY WARRANTY; without even the implied warranty of 010 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 011 * Lesser General Public License for more details. 012 * 013 * You should have received a copy of the GNU Lesser General Public 014 * License along with AutomataLib; if not, see 015 * http://www.gnu.de/documents/lgpl.en.html. 016 */ 017package net.automatalib.util.traversal; 018 019/** 020 * Enum to use for indicating if a node/state has been visited. 021 * <p> 022 * Note that this enum only declares one value. The value {@link #NOT_VISITED} for unvisited 023 * nodes/states is identified with <tt>null</tt>. 024 * 025 * @author Malte Isberner <malte.isberner@gmail.com> 026 * 027 */ 028public enum VisitedState { 029 /** 030 * Nodes that have already been visited. 031 */ 032 VISITED; 033 034 /** 035 * Nodes that have not yet been visited. 036 */ 037 public static final VisitedState NOT_VISITED = null; 038}