    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 *      http://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 */
    017package org.apache.commons.lang3.function;
    018
    019import java.util.Objects;
    020import java.util.function.Function;
    021
    022/**
    023 * Represents a function that accepts three arguments and produces a result. This is the three-arity specialization of
    024 * {@link Function}.
    025 *
    026 * <p>
    027 * This is a <a href="package-summary.html">functional interface</a> whose functional method is
    028 * {@link #apply(Object, Object, Object)}.
    029 * </p>
    030 *
    031 * @param <T> the type of the first argument to the function
    032 * @param <U> the type of the second argument to the function
    033 * @param <V> the type of the third argument to the function
    034 * @param <R> the type of the result of the function
    035 *
    036 * @see Function
    037 * @since 3.12.0
    038 */
    039@FunctionalInterface
    040public interface TriFunction<T, U, V, R> {
    041
    042    /**
    043     * Applies this function to the given arguments.
    044     *
    045     * @param t the first function argument
    046     * @param u the second function argument
    047     * @param v the third function argument
    048     * @return the function result
    049     */
    050    R apply(T t, U u, V v);
    051
    052    /**
    053     * Returns a composed function that first applies this function to its input, and then applies the {@code after}
    054     * function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the
    055     * composed function.
    056     *
    057     * @param <W> the type of output of the {@code after} function, and of the composed function
    058     * @param after the function to apply after this function is applied
    059     * @return a composed function that first applies this function and then applies the {@code after} function
    060     * @throws NullPointerException if after is null
    061     */
    062    default <W> TriFunction<T, U, V, W> andThen(final Function<? super R, ? extends W> after) {
    063        Objects.requireNonNull(after);
    064        return (final T t, final U u, final V v) -> after.apply(apply(t, u, v));
    065    }
    066}