001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.functor;
018
019/**
020 * Functor marker interface.  All provided functor interfaces extend this interface.
021 * <p>
022 * While not strictly required,
023 * it is <em>encouraged</em> that functor implementations:
024 * <ul>
025 *   <li>Implement {@link java.io.Serializable Serializable}</li>
026 *   <li>Override {@link java.lang.Object#equals(java.lang.Object)}</li>
027 *   <li>Override {@link java.lang.Object#hashCode()}</li>
028 *   <li>Override {@link java.lang.Object#toString()}</li>
029 * </ul>
030 * </p>
031 *
032 * @since 1.0
033 * @version $Revision: 1438784 $ $Date: 2013-01-26 01:09:13 +0100 (Sa, 26 Jan 2013) $
034 */
035public interface Functor {
036}