list_ex.s

(defvar friends (evar friends '()))
(defvar enemies (evar enemies '()))

(defun start
  (say "Halt, who goes there?")
  (add-response "A friend." add-friend)
  (add-response "An enemy." add-enemy))

(defun add-friend
  (set-var! friends (cons (get-name character) friends))
  (show-list friends))

(defun add-enemy
  (set-var! enemies (cons (get-name character) enemies))
  (show-list enemies))

(defun (show-list l)
  (describe (join " " l)))