(define (list-generator lst)
  (let ((l lst) (val '()) (return '()))
    (letrec (
      (continue (lambda (x)
        (call/cc (lambda (lap-to-go)
          (if (not (null? l))
            ((set! continue lap-to-go)
            (set! val (car l))
            (set! l (cdr l))
            (return val)))))
        (return '()))))
      (lambda ()
        (call/cc (lambda (where-to-go)
          (set! return where-to-go)
          (continue 'start)))))))
 
(define g (list-generator '(0 1 2 3 4)))
(print (g)) # 0
(print (g)) # 1
(print (g)) # 2
(print (g)) # 3
(print (g)) # 4