import java.util.*;

/** Our internal representation of a number in the X0 language.
 * See http://www.radford.edu/itec380/2019spring-ibarland/Project
 * 
 * @author Ian Barland
 * @version 2014.Nov.04
 */
public record Num(double x) implements Value, Expr {
  
  public Value eval() { return this; }  
  // Arg, `Value.java` has this (same) implemenation as default method, but javac
  // complains that we're implementing Expr w/o defining 'eval'.
  
  public String toString() { 
      // Let's make ints look better than, say, "43.0":
      // Omit trailing 0's after decimal, rounding to 9 places:
      return formatter.format(this.x);
      }
      
      
  public static Num parse( Scanner s, String punctuation ) {
      return new Num( UtilIan.nextDoubleSplittingBy(s,punctuation) );
      }
  private static java.text.DecimalFormat formatter = new java.text.DecimalFormat("#.#########");
      
  /** Return the Java double this Value represents
   *  (for use by other primitives in our language.)
   * @return the Java double this Value represents.
   */
  double doubleValue() { return this.x; }
  

  @Override
  /** Compare two Numbers, but with some tolerance. */
  public boolean equals( /* Num this, */ Object that) {
    if (this==that) {
      return true;
      }
   else if (that==null) {
      return false;
      }
   else if (this.getClass() != that.getClass()) {
      return false;
      }
   else {
      Num thatt = (Num) that;
      return UtilIan.equalsApprox(this.x,thatt.x);
      }
    
    }

 
  }