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 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package java.util.function;

import java.util.Objects;
import java.util.Comparator;

/**
 * Represents an operation upon two operands of the same type, producing a result
 * of the same type as the operands. This is a specialization of
 * {@link BiFunction} for the case where the operands and the result are all of
 * the same type.
 *
 * <p>This is a <a href="package-summary.html">functional interface</a>
 * whose functional method is {@link #apply(Object, Object)}.
 *
 * @param <T> the type of the operands and result of the operator
 *
 * @see BiFunction
 * @see UnaryOperator
 * @since 1.8
 */
@FunctionalInterface
public interface BinaryOperator<T> extends BiFunction<T,T,T> {
 /**
 * Returns a {@link BinaryOperator} which returns the lesser of two elements
 * according to the specified {@code Comparator}.
 *
 * @param <T> the type of the input arguments of the comparator
 * @param comparator a {@code Comparator} for comparing the two values
 * @return a {@code BinaryOperator} which returns the lesser of its operands,
 * according to the supplied {@code Comparator}
 * @throws NullPointerException if the argument is null
 */
 public static <T> BinaryOperator<T> minBy(Comparator<? super T> comparator) {
 Objects.requireNonNull(comparator);
 return (a, b) -> comparator.compare(a, b) <= 0 ? a : b;
 }

 /**
 * Returns a {@link BinaryOperator} which returns the greater of two elements
 * according to the specified {@code Comparator}.
 *
 * @param <T> the type of the input arguments of the comparator
 * @param comparator a {@code Comparator} for comparing the two values
 * @return a {@code BinaryOperator} which returns the greater of its operands,
 * according to the supplied {@code Comparator}
 * @throws NullPointerException if the argument is null
 */
 public static <T> BinaryOperator<T> maxBy(Comparator<? super T> comparator) {
 Objects.requireNonNull(comparator);
 return (a, b) -> comparator.compare(a, b) >= 0 ? a : b;
 }
}