package polyVisitor;

import arrayPoly.*;

/**
* Adds host polynomial to a constant.  Returns the resulting sum polynomial.
 <pre>
 * Copyright 2000, by Dung X. Nguyen, All rights reserved.
 </pre>
 * @author Dung X. Nguyen
 * @since 02/16/2000
*/
public class AddConst implements IVisitor
{
	public final static AddConst Singleton = new AddConst ();

	private AddConst()
	{
	}
	/**
	 * @param poly a Constant polynomial
	 * @param input a Double
	 * @return a APolynomial representing the sum of poly and input.
	 */
	public Object forConst (APolynomial poly, Object input)
	{
      return PolyFactory.MakeConstPoly (poly.getLeadCoef() + ((Double)input).doubleValue ());
	}

	/**
	 * @param poly a non-constant APolynomial
	 * @param input a Double
	 * @return a APolynomial representing the sum of poly and input.
	 */
	public Object forNonConst(APolynomial poly, Object input)
	{
      APolynomial lowerSum = (APolynomial)poly.getLowerPoly().execute (this, input);
      return PolyFactory.MakePoly (poly.getLeadCoef(), poly.getDegree(), lowerSum);
	}
}