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 * A functor that takes one argument and returns a <code>boolean</code> value.
021 * <p>
022 * Implementors are encouraged but not required to make their functors
023 * {@link java.io.Serializable Serializable}.
024 * </p>
025 *
026 * @param <A> the argument type.
027 * @since 1.0
028 * @version $Revision: 1508677 $ $Date: 2013-07-31 00:48:02 +0200 (Mi, 31 Jul 2013) $
029 */
030public interface Predicate<A> extends UnaryFunctor<A> {
031    /**
032     * Evaluate this predicate.
033     *
034     * @param obj the A object to test
035     * @return the result of this test
036     */
037    boolean test(A obj);
038}