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 *      https://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 */
017
018package org.apache.commons.io.function;
019
020import java.io.IOException;
021import java.io.UncheckedIOException;
022import java.util.Objects;
023import java.util.function.BiFunction;
024
025/**
026 * Like {@link BiFunction} but throws {@link IOException}.
027 *
028 * <p>
029 * This is a <a href="package-summary.html">functional interface</a> whose functional method is
030 * {@link #apply(Object, Object)}.
031 * </p>
032 *
033 * @param <T> the type of the first argument to the function
034 * @param <U> the type of the second argument to the function
035 * @param <R> the type of the result of the function
036 * @see BiFunction
037 * @since 2.12.0
038 */
039@FunctionalInterface
040public interface IOBiFunction<T, U, R> {
041
042    /**
043     * Creates a composed function that first applies this function to its input, and then applies the {@code after}
044     * function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the
045     * composed function.
046     *
047     * @param <V> the type of output of the {@code after} function, and of the composed function
048     * @param after the function to apply after this function is applied
049     * @return a composed function that first applies this function and then applies the {@code after} function
050     * @throws NullPointerException if after is null
051     */
052    default <V> IOBiFunction<T, U, V> andThen(final IOFunction<? super R, ? extends V> after) {
053        Objects.requireNonNull(after);
054        return (final T t, final U u) -> after.apply(apply(t, u));
055    }
056
057    /**
058     * Applies this function to the given arguments.
059     *
060     * @param t the first function argument
061     * @param u the second function argument
062     * @return the function result
063     * @throws IOException if an I/O error occurs.
064     */
065    R apply(T t, U u) throws IOException;
066
067    /**
068     * Creates a {@link BiFunction} for this instance that throws {@link UncheckedIOException} instead of
069     * {@link IOException}.
070     *
071     * @return an UncheckedIOException BiFunction.
072     */
073    default BiFunction<T, U, R> asBiFunction() {
074        return (t, u) -> Uncheck.apply(this, t, u);
075    }
076}