1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.functor;
18  
19  /**
20   * Functor marker interface.  All provided functor interfaces extend this interface.
21   * <p>
22   * While not strictly required,
23   * it is <em>encouraged</em> that functor implementations:
24   * <ul>
25   *   <li>Implement {@link java.io.Serializable Serializable}</li>
26   *   <li>Override {@link java.lang.Object#equals(java.lang.Object)}</li>
27   *   <li>Override {@link java.lang.Object#hashCode()}</li>
28   *   <li>Override {@link java.lang.Object#toString()}</li>
29   * </ul>
30   * </p>
31   *
32   * @since 1.0
33   * @version $Revision: 1349928 $ $Date: 2012-06-13 12:53:27 -0300 (Wed, 13 Jun 2012) $
34   */
35  public interface Functor {
36  }