/* SeqExpr.java */

/* A class to represent sequences of assignment statements and 
 * other expressions.  The value of the entire sequence is the 
 * value of the last expression, in the environment created by 
 * the assignments that preceed it.
 */

public class SeqExpr extends Expression {
  private Expression exp1;
  private Expression exp2;

  /** Constructs a Sequence expression.
   * @param e1 the first expression in the sequence.
   * @param e2 the second expression in the sequence.
   */
  public SeqExpr(Expression e1, Expression e2) {
    /* Fill in for part 2. */
  }

  public int arity() { 
    return 2;
  }

  public String oper() { 
    return "sequence";
  }

  public Expression operand(int i) {
    /* Fill in for part 2. */
  }

  public Value eval() {
    /* Fill in for part 2. */
  }
}