;;; here is a circular function:
(let ()
(define (cfunc)
(begin
(display "cfunc! ")
#f))
(let ((clst (procedure-source cfunc)))
(set! (cdr (cdr (car (cdr (cdr clst)))))
(cdr (car (cdr (cdr clst))))))
(cfunc)) ; displays "func! " until you kill it
;;; could you implement goto's with circular lists?
;;; unreadable and unprintable code -- this is great.