;; -*- geiser-scheme-implementation: guile -*-

(define chest 'sword)

chest  ;  sword

(set! chest 'gold) ;  #<unspecified>

chest ;  gold


(define (make-countdown n)
  (lambda ()
    (define last-n n)
    (if (zero? n)
        0
        (begin
          (set! n (- n 1))
          last-n))))
(define cdown (make-countdown 3))

(cdown) ;  3
(cdown) ;  2
(cdown) ;  1
(cdown) ;  0
(cdown) ;  0

(define vec (vector 'a 'b 'c))
vec ;  #(a b c)
(vector-ref vec 1) ;  b
(vector-set! vec 1 'boop)
(vector-ref vec 1) ;  boop
vec ;  #(a boop c)