    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.BinaryOperator;
    024
    025/**
    026 * Like {@link BinaryOperator} but throws {@link IOException}.
    027 *
    028 * @param <T> the type of the operands and result of the operator.
    029 * @see IOBiFunction
    030 * @see BinaryOperator
    031 * @since 2.12.0
    032 */
    033@FunctionalInterface
    034public interface IOBinaryOperator<T> extends IOBiFunction<T, T, T> {
    035
    036    /**
    037     * Creates a {@link IOBinaryOperator} which returns the greater of two elements according to the specified
    038     * {@code Comparator}.
    039     *
    040     * @param <T> the type of the input arguments of the comparator.
    041     * @param comparator a {@code Comparator} for comparing the two values.
    042     * @return a {@code BinaryOperator} which returns the greater of its operands, according to the supplied
    043     *         {@code Comparator}
    044     * @throws NullPointerException if the argument is null.
    045     */
    046    static <T> IOBinaryOperator<T> maxBy(final IOComparator<? super T> comparator) {
    047        Objects.requireNonNull(comparator);
    048        return (a, b) -> comparator.compare(a, b) >= 0 ? a : b;
    049    }
    050
    051    /**
    052     * Creates a {@link IOBinaryOperator} which returns the lesser of two elements according to the specified
    053     * {@code Comparator}.
    054     *
    055     * @param <T> the type of the input arguments of the comparator.
    056     * @param comparator a {@code Comparator} for comparing the two values.
    057     * @return a {@code BinaryOperator} which returns the lesser of its operands, according to the supplied
    058     *         {@code Comparator}
    059     * @throws NullPointerException if the argument is null.
    060     */
    061    static <T> IOBinaryOperator<T> minBy(final IOComparator<? super T> comparator) {
    062        Objects.requireNonNull(comparator);
    063        return (a, b) -> comparator.compare(a, b) <= 0 ? a : b;
    064    }
    065
    066    /**
    067     * Creates a {@link BinaryOperator} for this instance that throws {@link UncheckedIOException} instead of
    068     * {@link IOException}.
    069     *
    070     * @return an unchecked BiFunction.
    071     */
    072    default BinaryOperator<T> asBinaryOperator() {
    073        return (t, u) -> Uncheck.apply(this, t, u);
    074    }
    075}