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}