001/* 002 * Copyright (c) 2007-2016 Concurrent, Inc. All Rights Reserved. 003 * 004 * Project and contact information: http://www.cascading.org/ 005 * 006 * This file is part of the Cascading project. 007 * 008 * Licensed under the Apache License, Version 2.0 (the "License"); 009 * you may not use this file except in compliance with the License. 010 * You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, software 015 * distributed under the License is distributed on an "AS IS" BASIS, 016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 017 * See the License for the specific language governing permissions and 018 * limitations under the License. 019 */ 020 021package cascading.operation; 022 023import cascading.flow.FlowProcess; 024 025/** 026 * Interface Filter marks a given {@link Operation} as a filter, as opposed to being a {@link Function}. 027 * <p/> 028 * A Filter is responsible for testing a Tuple to see if it should be removed from the tuple stream. 029 * <p/> 030 * To implement a Filter, (optionally) sub-class {@link BaseOperation} and have the new sub-class {@code implement} 031 * this interface. 032 */ 033public interface Filter<Context> extends Operation<Context> 034 { 035 /** 036 * Method isRemove returns true if input should be removed from the tuple stream. 037 * 038 * @param flowProcess of type FlowProcess 039 * @param filterCall of type FilterCall 040 * @return boolean 041 */ 042 boolean isRemove( FlowProcess flowProcess, FilterCall<Context> filterCall ); 043 }