    001// Copyright 2010, 2011 The Apache Software Foundation
    002//
    003// Licensed under the Apache License, Version 2.0 (the "License");
    004// you may not use this file except in compliance with the License.
    005// You may obtain a copy of the License at
    006//
    007// http://www.apache.org/licenses/LICENSE-2.0
    008//
    009// Unless required by applicable law or agreed to in writing, software
    010// distributed under the License is distributed on an "AS IS" BASIS,
    011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012// See the License for the specific language governing permissions and
    013// limitations under the License.
    014
    015package org.apache.tapestry5.func;
    016
    017/**
    018 * Used when filtering a collection of objects of a given type; the predicate is passed
    019 * each object in turn, and returns true to include the object in the result collection.
    020 * <p>
    021 * The {@link F} class includes a number of Predicate factory methods.
    022 * <p>
    023 * This was converted from a abstract base class to an interface in 5.3.
    024 *
    025 * @since 5.2.0
    026 * @see Flow#filter(Predicate)
    027 * @see Flow#remove(Predicate)
    028 */
    029public interface Predicate<T>
    030{
    031    /**
    032     * This method is overridden in subclasses to define which objects the Predicate will accept
    033     * and which it will reject.
    034     *
    035     * @param element
    036     *            the element from the flow to be evaluated by the Predicate
    037     */
    038    boolean accept(T element);
    039}