Danny Milosavljevic <[email protected]> writes:
> (define (skip-comments text)
> (replace (string-append "//[^\n]*?|"
> "/[*].*?[*]/|"
> "'([.]|[^'])*?'|"
> "\"([.]|[^\"])*?\"")
This last part will remove anything between double quotes, such as every
string. Another problem seems to be the handling of /* comments */.
It’s a greedy regex that will swallow any character until it finally
hits */ — even if the characters in between may have been */.
I would not use regular expressions here but a read loop such as this:
--8<---------------cut here---------------start------------->8---
(define (strip-comments port)
(let loop ((char (get-char port))
(balance 0)
(chars '()))
(cond
;; done!
((eof-object? char)
(list->string (reverse chars)))
;; line comment
((and (equal? char #\/)
(equal? #\/ (peek-char port)))
(begin (read-line port)
(loop (get-char port) balance chars)))
;; begin of block comment
((and (equal? char #\/)
(equal? #\* (peek-char port)))
(begin (read-char port)
(loop (get-char port) (1+ balance) chars)))
;; end of block comment
((and (positive? balance)
(equal? char #\*)
(equal? #\/ (peek-char port)))
(begin (read-char port)
(loop (get-char port) (1- balance) chars)))
;; inside block comment
((positive? balance)
(loop (get-char port) balance chars))
;; just a plain ol’ character
(else (loop (get-char port) balance (cons char chars))))))
;; Strip all comments from the file “fname” and show the result.
(display (call-with-input-file fname strip-comments))
--8<---------------cut here---------------end--------------->8---
--
Ricardo
