// Prim.java

/** A primitive regular expression. 
 *  @author <a href="mailto:bergmann@rowan.edu"> Seth Bergmann </a>
 *  @author <a href="mailto:gspyo@jersey.net"> Greg Safko </a>
 */
public abstract class Prim extends Expr
{  
   	private Character symbol;
   	/** Private variables for an expression.
     *  @param symbol The primitive symbol of the alphabet for this expression
     */
    
   	public Prim (Character a)
    {	
   		super(a);
   			 
   	}

   	public Character getValue()
   	{ 
 	 	return symbol;
   	}
   
   	public String toString ()
   	{ 
   		return symbol.toString();
   	}

 
   	public abstract boolean isEpsilon();
   	
   	public abstract boolean isNull();
     

}