001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019package org.apache.reef.tang.util.walk; 020 021/** 022 * Generic interface to traverse edges of the configuration graph. 023 * It is used e.g. in Walk.preorder() 024 */ 025public interface EdgeVisitor<T> { 026 027 /** 028 * Process current edge of the configuration graph. 029 * 030 * @param nodeFrom Current configuration node. 031 * @param nodeTo Destination configuration node. 032 * @return true to proceed with the next node, false to cancel. 033 */ 034 boolean visit(T nodeFrom, T nodeTo); 035}