Re: can format ~{...~} enumerate list items?

Pascal J. Bourguignon wrote:

(defun counting (list &optional (from 1))
  (mapcar (let ((i (1- from)))
            (lambda (x)
              (if (consp x)
                  (cons (incf i) x)
                  (list (incf i) x))))
          list))
 
(let ((arguments '(aa bb cc)))
  (format t "~:{~A. ~A~%~}"  (counting arguments)))
 
1. AA
2. BB
3. CC

Gauche Scheme

(define (print-counted the-list :optional (from 0))
  (for-each
    (lambda (i x) (print i ". " x))
    (lrange from)
    the-list))

gosh> (print-counted '(a bb ccc))
0. a
1. bb
2. ccc

gosh> (print-counted '(a bb ccc) 233)
233. a
234. bb
235. ccc

Shorter:

(define (print-counted the-list :optional (from 0))
  (for-each
    (cut print <> ". " <>)
    (lrange from)
    the-list))