MonomialAdder.java

/*******************************************************************************
 * Copyright (c) 2013 Stephen F. Siegel, University of Delaware.
 * 
 * This file is part of SARL.
 * 
 * SARL is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option) any
 * later version.
 * 
 * SARL is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with SARL. If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package edu.udel.cis.vsl.sarl.ideal.common;

import edu.udel.cis.vsl.sarl.ideal.IF.Constant;
import edu.udel.cis.vsl.sarl.ideal.IF.Monomial;
import edu.udel.cis.vsl.sarl.util.BinaryOperator;

/**
 * Add c0*m + c1*m, where m is a monic and c0 and c1 are constants. The answer
 * is (c0+c1)*m, or null if c0+c1=0.
 * 
 * @author siegel
 * 
 */
class MonomialAdder implements BinaryOperator<Monomial> {
	private CommonIdealFactory factory;

	public MonomialAdder(CommonIdealFactory factory) {
		this.factory = factory;
	}

	@Override
	public Monomial apply(Monomial arg0, Monomial arg1) {
		Constant c = factory.add(arg0.monomialConstant(factory),
				arg1.monomialConstant(factory));

		if (c.isZero())
			return null;
		return factory.monomial(c, arg0.monic(factory));
	}
}