1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.collections4;
19
20 import java.util.function.Consumer;
21 import java.util.function.Supplier;
22
23 /**
24 * Defines a functor interface implemented by classes that do something.
25 * <p>
26 * A {@code Closure} represents a block of code which is executed from inside some block, function or iteration. It operates an input object.
27 * </p>
28 * <p>
29 * Standard implementations of common closures are provided by {@link ClosureUtils}. These include method invocation and for/while loops.
30 * </p>
31 *
32 * @param <T> The type of the input to the operation.
33 * @since 1.0 This will be deprecated in 5.0 in favor of {@link Supplier}.
34 */
35 //@Deprecated
36 public interface Closure<T> extends Consumer<T> {
37
38 @Override
39 default void accept(final T input) {
40 execute(input);
41 }
42
43 /**
44 * Performs an action on the specified input object.
45 *
46 * @param input The input to execute on.
47 * @throws ClassCastException (runtime) if the input is the wrong class.
48 * @throws IllegalArgumentException (runtime) if the input is invalid.
49 * @throws FunctorException (runtime) if any other error occurs.
50 */
51 void execute(T input);
52 }