Sum.java

/*
 * Copyright (c) 2013, SRI International
 * All rights reserved.
 * Licensed under the The BSD 3-Clause License;
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 * 
 * http://opensource.org/licenses/BSD-3-Clause
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 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright
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 * Redistributions in binary form must reproduce the above copyright
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 * documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of the aic-util nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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package com.sri.ai.util.rangeoperation.library.operators;

import com.google.common.annotations.Beta;
import com.sri.ai.util.rangeoperation.core.AbstractAggregateOperator;

/**
 * A summation aggregate operator over numbers.
 * TODO: extend it to arbitrarily nested lists of numbers.
 * 
 * @author braz
 */
@Beta
public class Sum extends AbstractAggregateOperator<Number, Number> {
	
	@Override
	public void initialize() {
		result = 0;
	}
	
	@Override
	public void increment(Number another) {
		try {
			result = result.doubleValue() + another.doubleValue();
		}
		catch (ClassCastException e) {
			throw new Error("com.sri.ai.util.rangeoperation.library.operators.Sum applied to non-Number object " + another);
		}
	}
}