//File: ExclusiveDisjunction.java
//Name: Trai Pham
//Date: 02/16/2020
//Course: CSE 8B
/**
Not sure what Negation does
*/

public class ExclusiveDisjunction extends BooleanExpression{
  public ExclusiveDisjunction(BooleanExpression var1, BooleanExpression var2){
    this.a = var1;
    this.b = var2;
  }
  public Value evaluate(){
//operand error
    if(!(this.a instanceof BooleanExpression) ||
    !(this.b instanceof BooleanExpression)){
      return null;
    }
    if(this.a == null || this.b == null){
      return null;
    }
//declaring Value variables
    Value test01 = this.a.evaluate();
    Value test02 = this.b.evaluate();

    Value compare01 = new BooleanValue(((BooleanValue)test01).boolEvaluate() !=
    ((BooleanValue)test02).boolEvaluate());
    return compare01;
  }
}