package funpoly;

import funpoly.visitor.IVisitor;

/**
* Represents the constant polynomial type.
* @author Dung X. Nguyen
*/
class ConstPoly extends APolynomial
{
   /**
	 * @param coef  the coefficient.
	 */
	ConstPoly(int coef)
	{
      _coef = coef;
	}

	public int getDegree()
	{
		return (0);
	}

	/**
	 * Throws NoSuchElementException.
	 */
	public APolynomial getLowerPoly()
	{
		throw new java.util.NoSuchElementException ("Constant polynomial has no lower order term!");
	}

   public String toString ()
   {
      return Integer.toString(_coef);
   }

   String toStringHelp ()
   {
      return (0 == _coef)? "": " + " + Integer.toString(_coef);
   }

	/**
	 * Calls algo.forConst to carry out the task.
	 */
	public Object execute(IVisitor algo, Object input)
	{
		return algo.forConst(this, input);
	}
}