    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 */
    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 *
    030 * @see IOBiFunction
    031 * @see BinaryOperator
    032 * @since 2.12.0
    033 */
    034@FunctionalInterface
    035public interface IOBinaryOperator<T> extends IOBiFunction<T, T, T> {
    036
    037    /**
    038     * Creates a {@link IOBinaryOperator} which returns the greater of two elements according to the specified
    039     * {@code Comparator}.
    040     *
    041     * @param <T> the type of the input arguments of the comparator
    042     * @param comparator a {@code Comparator} for comparing the two values
    043     * @return a {@code BinaryOperator} which returns the greater of its operands, according to the supplied
    044     *         {@code Comparator}
    045     * @throws NullPointerException if the argument is null
    046     */
    047    static <T> IOBinaryOperator<T> maxBy(final IOComparator<? super T> comparator) {
    048        Objects.requireNonNull(comparator);
    049        return (a, b) -> comparator.compare(a, b) >= 0 ? a : b;
    050    }
    051
    052    /**
    053     * Creates a {@link IOBinaryOperator} which returns the lesser of two elements according to the specified
    054     * {@code Comparator}.
    055     *
    056     * @param <T> the type of the input arguments of the comparator
    057     * @param comparator a {@code Comparator} for comparing the two values
    058     * @return a {@code BinaryOperator} which returns the lesser of its operands, according to the supplied
    059     *         {@code Comparator}
    060     * @throws NullPointerException if the argument is null
    061     */
    062    static <T> IOBinaryOperator<T> minBy(final IOComparator<? super T> comparator) {
    063        Objects.requireNonNull(comparator);
    064        return (a, b) -> comparator.compare(a, b) <= 0 ? a : b;
    065    }
    066
    067    /**
    068     * Creates a {@link BinaryOperator} for this instance that throws {@link UncheckedIOException} instead of
    069     * {@link IOException}.
    070     *
    071     * @return an unchecked BiFunction.
    072     */
    073    default BinaryOperator<T> asBinaryOperator() {
    074        return (t, u) -> Uncheck.apply(this, t, u);
    075    }
    076}