    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 *      https://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 */
    017
    018package org.apache.commons.collections4;
    019
    020import java.util.function.Consumer;
    021import java.util.function.Supplier;
    022
    023/**
    024 * Defines a functor interface implemented by classes that do something.
    025 * <p>
    026 * A {@code Closure} represents a block of code which is executed from inside some block, function or iteration. It operates an input object.
    027 * </p>
    028 * <p>
    029 * Standard implementations of common closures are provided by {@link ClosureUtils}. These include method invocation and for/while loops.
    030 * </p>
    031 *
    032 * @param <T> The type of the input to the operation.
    033 * @since 1.0 This will be deprecated in 5.0 in favor of {@link Supplier}.
    034 */
    035//@Deprecated
    036public interface Closure<T> extends Consumer<T> {
    037
    038    @Override
    039    default void accept(final T input) {
    040        execute(input);
    041    }
    042
    043    /**
    044     * Performs an action on the specified input object.
    045     *
    046     * @param input The input to execute on.
    047     * @throws ClassCastException       (runtime) if the input is the wrong class.
    048     * @throws IllegalArgumentException (runtime) if the input is invalid.
    049     * @throws FunctorException         (runtime) if any other error occurs.
    050     */
    051    void execute(T input);
    052}