Note: We change j-eval so that it never returns an
answer. Instead, we pass it a third argument (its
continuation) and it calls that when it has computed the
answer.
(define (j-eval-block exp env next)
(define (loop exprs)
(if (null? exprs)
(next "End of block")
(j-eval (car exprs) env
(lambda (val) (loop (cdr exprs))))))
(loop (cdr exp)))
(define (j-eval-oops exp env next)
; Never calls NEXT!!!
(let ((name (second exp)))
(let ((label (find-label name)))
(if label
(label)
(error "No handler for error" name)))))
