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