001//***************************************************************************************************************************
002//* Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003//* distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004//* to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005//* with the License.  You may obtain a copy of the License at                                                              *
006//*                                                                                                                         *
007//*  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008//*                                                                                                                         *
009//* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010//* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011//* specific language governing permissions and limitations under the License.                                              *
012//***************************************************************************************************************************
013package org.apache.juneau.internal;
014
015import java.util.*;
016import java.util.function.*;
017
018/**
019 * A function that takes in 4 arguments.
020 *
021 * <h5 class='section'>See Also:</h5><ul>
022 * </ul>
023 *
024 * @param <A> The first argument.
025 * @param <B> The second argument.
026 * @param <C> The third argument.
027 * @param <D> The fourth argument.
028 * @param <R> The return type.
029 */
030@SuppressWarnings("javadoc")
031@FunctionalInterface
032public interface Function4<A,B,C,D,R> {
033
034   R apply(A a, B b, C c, D d);
035
036   default <V> Function4<A, B, C, D, V> andThen(Function<? super R, ? extends V> after) {
037      Objects.requireNonNull(after);
038      return (A a, B b, C c, D d) -> after.apply(apply(a, b, c ,d));
039   }
040}