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 package org.apache.commons.lang3.function;
18
19 import java.util.Objects;
20 import java.util.function.Function;
21
22 /**
23 * Represents a function that accepts three arguments and produces a result. This is the three-arity specialization of
24 * {@link Function}.
25 *
26 * <p>
27 * This is a <a href="package-summary.html">functional interface</a> whose functional method is
28 * {@link #apply(Object, Object, Object)}.
29 * </p>
30 *
31 * @param <T> the type of the first argument to the function
32 * @param <U> the type of the second argument to the function
33 * @param <V> the type of the third argument to the function
34 * @param <R> the type of the result of the function
35 *
36 * @see Function
37 * @since 3.12.0
38 */
39 @FunctionalInterface
40 public interface TriFunction<T, U, V, R> {
41
42 /**
43 * Returns a composed function that first applies this function to its input, and then applies the {@code after}
44 * function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the
45 * composed function.
46 *
47 * @param <W> the type of output of the {@code after} function, and of the composed function
48 * @param after the function to apply after this function is applied
49 * @return a composed function that first applies this function and then applies the {@code after} function
50 * @throws NullPointerException if after is null
51 */
52 default <W> TriFunction<T, U, V, W> andThen(final Function<? super R, ? extends W> after) {
53 Objects.requireNonNull(after);
54 return (final T t, final U u, final V v) -> after.apply(apply(t, u, v));
55 }
56
57 /**
58 * Applies this function to the given arguments.
59 *
60 * @param t the first function argument
61 * @param u the second function argument
62 * @param v the third function argument
63 * @return the function result
64 */
65 R apply(T t, U u, V v);
66 }