package rebelsky.pal;

/**
 * An integer constant for PAL.
 *
 * @author Samuel A. Rebelsky
 * @version 1.1 of December 2002
 */
public class IConstant
  extends Variable
{
  // +--------+------------------------------------------------------------
  // | Fields |
  // +--------+

  /** The value of the constant. */
  int value;


  // +--------------+------------------------------------------------------
  // | Constructors |
  // +--------------+

  /**
   * Build a new integer constannt.
   */
  public IConstant(int val) {
    this.value = val;
  } // IConstant()


  // +---------+-----------------------------------------------------------
  // | Methods |
  // +---------+

  /** 
   * Get the integer stored in this constant. 
   */
  public int iget(Computer hal)
  {
    return this.value;
  } // iget()

  /**
   * Fail to set the value of the constant.
   *
   * @exception Exception
   *   Whenever this procedure is called (you can't change constants).
   */
  public void iset(Computer hal, int newval)
    throws Exception
  {
    throw new Exception("Can't change the value of constants.");
  } // iset(int)

  /** Convert the location to a string (usually for printing). */
  public String toString() {
    return "$" + this.value;
  } // toString()

} // class IConstant