/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
**********************************************************************************************************************/
package eu.stratosphere.util;
/**
* A visitor encapsulates functionality that is applied to each node in the process of a traversal of a tree or DAD.
*/
public interface Visitor<T extends Visitable<T>> {
/**
*
* @param visitable
*
* @return True, if the traversal should continue, false otherwise.
*/
boolean preVisit(T visitable);
/**
* @param visitable
*/
void postVisit(T visitable);
}