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 * http://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.io.function;
19
20 import java.io.IOException;
21 import java.io.UncheckedIOException;
22 import java.util.function.UnaryOperator;
23
24 /**
25 * Like {@link UnaryOperator} but throws {@link IOException}.
26 *
27 * @param <T> the type of the operand and result of the operator.
28 *
29 * @see UnaryOperator
30 * @see IOFunction
31 * @since 2.12.0
32 */
33 @FunctionalInterface
34 public interface IOUnaryOperator<T> extends IOFunction<T, T> {
35
36 /**
37 * Creates a unary operator that always returns its input argument.
38 *
39 * @param <T> the type of the input and output of the operator.
40 * @return a unary operator that always returns its input argument.
41 */
42 static <T> IOUnaryOperator<T> identity() {
43 return t -> t;
44 }
45
46 /**
47 * Creates a {@link UnaryOperator} for this instance that throws {@link UncheckedIOException} instead of
48 * {@link IOException}.
49 *
50 * @return an unchecked BiFunction.
51 */
52 default UnaryOperator<T> asUnaryOperator() {
53 return t -> Uncheck.apply(this, t);
54 }
55
56 }