(???) ; Very simple guestbook
 (???) lambda (entry)
 (???)  (import (chicken string)
 (???)          (chicken time posix)
 (???)          (chicken pretty-print))
 (???)  (let* ((res (with-input-from-file "guestbook" read))
 (???)         (records (if (eof-object? res) '() res)))
 (???)    (with-output-to-file "guestbook"
 (???)      (lambda ()
 (???)        (pretty-print (cons (list (seconds->string)
 (???)                                  entry)
 (???)                            records)))))
 (???)  (list (conc "Thanks for signing my guestbook.")))