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 */
017package org.apache.commons.functor.aggregator.functions;
018
019import org.apache.commons.functor.BinaryFunction;
020
021/**
022 * Aggregation function to be used with subclasses of
023 * {@link org.apache.commons.functor.aggregator.AbstractNoStoreAggregator} which
024 * finds the maximum of 2 double(s).
025 */
026public final class DoubleMaxAggregatorBinaryFunction implements BinaryFunction<Double, Double, Double> {
027    /**
028     * Computes the maximum of the 2 given numbers and returns the result.
029     *
030     * @param left
031     *            first number to compare. If <code>null</code>, then
032     *            <code>right</code> will be returned.
033     * @param right
034     *            second number to add. If <code>null</code>, then
035     *            <code>left</code> will be returned.
036     * @return max of the 2 double's as described above
037     */
038    public Double evaluate(Double left, Double right) {
039        if (left == null) {
040            return right;
041        }
042        if (right == null) {
043            return left;
044        }
045        if (left.doubleValue() < right.doubleValue()) {
046            return right;
047        }
048        return left;
049    }
050
051    @Override
052    public String toString() {
053        return DoubleMaxAggregatorBinaryFunction.class.getName();
054    }
055}