(provide! (generator)
  (defn (aux f)
    (define here (get-current-environment))

    (defn (start #ignore)
      (reset
        (lambda (p)
          (f (lambda (v)
                (shift p
                  (lambda (k)
                    (set! here start k)
                    v)))))))

    (lambda () (start #inert)))

  (define quote (vau (e) #ignore e))

  (define generator
    (vau body e
      (eval (list aux (list* lambda (quote (yield)) body)) e))))