001/* 002 * Copyright (c) 2016-2017 Chris K Wensel <chris@wensel.net>. All Rights Reserved. 003 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved. 004 * 005 * Project and contact information: http://www.cascading.org/ 006 * 007 * This file is part of the Cascading project. 008 * 009 * Licensed under the Apache License, Version 2.0 (the "License"); 010 * you may not use this file except in compliance with the License. 011 * You may obtain a copy of the License at 012 * 013 * http://www.apache.org/licenses/LICENSE-2.0 014 * 015 * Unless required by applicable law or agreed to in writing, software 016 * distributed under the License is distributed on an "AS IS" BASIS, 017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 018 * See the License for the specific language governing permissions and 019 * limitations under the License. 020 */ 021 022package cascading.operation; 023 024import cascading.flow.FlowProcess; 025 026/** 027 * Interface Filter marks a given {@link Operation} as a filter, as opposed to being a {@link Function}. 028 * <p> 029 * A Filter is responsible for testing a Tuple to see if it should be removed from the tuple stream. 030 * <p> 031 * To implement a Filter, (optionally) sub-class {@link BaseOperation} and have the new sub-class {@code implement} 032 * this interface. 033 */ 034public interface Filter<Context> extends Operation<Context> 035 { 036 /** 037 * Method isRemove returns true if input should be removed from the tuple stream. 038 * 039 * @param flowProcess of type FlowProcess 040 * @param filterCall of type FilterCall 041 * @return boolean 042 */ 043 boolean isRemove( FlowProcess flowProcess, FilterCall<Context> filterCall ); 044 }