;; The first three lines of this file were inserted by DrScheme. They record metadata
;; about the language level of this file in a form that our tools can easily process.
#reader(lib "reader.ss" "plai" "lang")


;
; try {
;    s = sum(L);
;    System.out.println("After 1st assignment");
;    s = s + 1;
; } catch (Exception e) {
;    System.out.print("Bad: ");
;    System.out.println(e);
; }

(define (sum values throw)
  (cond [(null? values)                0]
        [(number? (first values))      (+ (first values) (sum (rest values) throw))]
        [else                          (throw 'Not-a-number)]))

(define s 0)
(define L '(1 2 3 x 5))

(let ([e
       (call/cc
        (λ (throw)
          (set! s (sum L throw))
          (display "After 1st assignment")
          (set! s (+ s 1))
          ))])
  (if (void? e)
      (void) ; Completed without error
      (begin (display "Bad: ")
             (display e))))