// **** Imports ****
import java.io.*;
import java.util.*;
/*
 * @Date: 7/28/2018
 * @author James Brink, brinkje@plu.edu
 */
public class TrivialExample {

   double xVal, yVal, infixVal;
   String infix;
   ExprEvaluator evaluator = new ExprEvaluator();
   Scanner scan = new Scanner(System.in);

   /**
    * Constructor for TrivialExample.
    *
    * Note:  in this case, the expression only uses x and y.  Hence the t
    * parameter is just set to 0 when evaluating the expression.
    */
   public TrivialExample() {
      // get input
      System.out.print("Enter the value for x: ");
      xVal = scan.nextDouble();
      System.out.print("Enter the value for y: ");
      yVal = scan.nextDouble();
      scan.nextLine();   //  read rest of line
      System.out.print("Enter the expression to be evaluated: ");
      infix = scan.nextLine();

      // evaluate expression
      try {
         evaluator.buildFromInfix(infix);
         infixVal = evaluator.evaluate(0, xVal, yVal);  // t = 0
         System.out.println("x =" + xVal + ", y = " + yVal
                                   + ", expression = " + infixVal);
      } catch (Exception e) {
         System.out.println ("Error:  namely: " + e);
      }
   }  // constructor TrivialExample

   /**
    * Trivial main program that starts the application.
    */
   public static void main (String args[]) {
      TrivialExample app = new TrivialExample();
      System.exit(0);
   }  // end main

} // class TrivialExample