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;; text-menu.lisp

;; A simple tool for presenting options to the user of a Lisp program.
;; Lee Spector, October 16, 1997

;; example: (text-menu '(fish (frogs and pickles) typewriters))


(defun text-menu (items)
  "Prints the provided items (which should be in a list) with a number
for each and prompts the user to choose one by typing a number. Returns
the chosen item. Doesn't check that the user's input is reasonable;
unreasonable inputs will cause errors."
  ;; print the initial instructions
  (format t "~%Choose one of the following by typing a number:")
  ;; print the numbers and items
  (dotimes (item-number (length items))
    (format t "~%~A: ~A" (+ item-number 1) (nth item-number items)))
  ;; prompt for the choice
  (format t "~%Choice: ")
  ;; read the user's choice and return the chosen item
  (nth (- (read) 1) items))