org.jgrapht.util.WeightCombiner Maven / Gradle / Ivy
/*
* (C) Copyright 2009-2020, by Ilya Razenshteyn and Contributors.
*
* JGraphT : a free Java graph-theory library
*
* See the CONTRIBUTORS.md file distributed with this work for additional
* information regarding copyright ownership.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0, or the
* GNU Lesser General Public License v2.1 or later
* which is available at
* http://www.gnu.org/licenses/old-licenses/lgpl-2.1-standalone.html.
*
* SPDX-License-Identifier: EPL-2.0 OR LGPL-2.1-or-later
*/
package org.jgrapht.util;
import java.io.*;
/**
* Binary operator for edge weights. There are some prewritten operators.
*/
public interface WeightCombiner
{
/**
* Sum of weights.
*/
WeightCombiner SUM = (WeightCombiner & Serializable) (a, b) -> a + b;
/**
* Multiplication of weights.
*/
WeightCombiner MULT = (WeightCombiner & Serializable) (a, b) -> a * b;
/**
* Minimum weight.
*/
WeightCombiner MIN = (WeightCombiner & Serializable) Math::min;
/**
* Maximum weight.
*/
WeightCombiner MAX = (WeightCombiner & Serializable) Math::max;
/**
* First weight.
*/
WeightCombiner FIRST = (WeightCombiner & Serializable) (a, b) -> a;
/**
* Second weight.
*/
WeightCombiner SECOND = (WeightCombiner & Serializable) (a, b) -> b;
/**
* Combines two weights.
*
* @param a first weight
* @param b second weight
*
* @return result of the operator
*/
double combine(double a, double b);
}