001/* 002 * Copyright (C) 2009-2011 Mathias Doenitz 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.parboiled.trees; 018 019import java.util.List; 020 021/** 022 * A node in a directed graph (that may have cycles). 023 * The children list must not contain null entries. 024 * 025 * @param <T> the actual implementation type of this graph node 026 */ 027public interface GraphNode<T extends GraphNode<T>> { 028 029 /** 030 * Returns the sub nodes of this node. 031 * 032 * @return the sub nodes 033 */ 034 List<T> getChildren(); 035 036}