Re: Use of format or pprint

Here are some functions I've written to convert strings into
lists of various sorts. Examples follow at the end.
 
(defun list-from-string (string
                         &key
                         (start 0)
                         (char-bag '(#\Space))
                         (test #'(lambda (ch)
                                   (not (member ch char-bag
                                                :test 'char=))))
                         (post-process 'identity))
  (let ((pos (position-if test string :start start)))
    (if pos
      (list-from-string* string :start  pos :char-bag char-bag
                         :test test :post-process post-process)
      nil)))
 
(defun list-from-string* (string
                          &key
                          (start 0)
                          (char-bag '(#\Space))
                          (test #'(lambda (ch)
                                    (not (member ch char-bag :test 'char=))))
                          (post-process 'identity))
  (let* ((pos (position-if-not test string :start start))
         (new-pos (if pos (position-if test string :start pos) nil)))
    (cond
     ((and pos new-pos)
      (cons (funcall post-process (subseq string start pos))
            (list-from-string* string :start new-pos :char-bag char-bag
                               :test test :post-process post-process)))
     (pos (list (funcall post-process (subseq string start pos))))
 
     (t (list (funcall post-process (subseq string start)))))))

 ....

(list-from-string "chris! dan! ski! elaine! nick!"
                  :char-bag '(#\Space #\!)) -->
  ("chris" "dan" "ski" "elaine" "nick")

Gauche Scheme

(use srfi-13)
(use srfi-14)

(string-tokenize
  "  chris!..?..!dan!ski!;elaine! nick!   "
  char-set:letter)

  ===>
("chris" "dan" "ski" "elaine" "nick")