Re: Counting SLOC in Emacs

[Stefan Monnier]

>> And don't re-call use-region-p here, in the off-chance that it returns
>> something else than in the first call.  E.g. you can use (if (and (=
>> beg (point-min)) (= end (point-max))) "buffer" "region") instead.
> I don't think it's probable (or even possible), but definitely my
> solution was not very elegant.  I wonder whether (let)ting
> (use-region-p) to a temporary variable wouldn't be better.

Yes, it should be passed as an additional argument (you could pass
`region' or `buffer' as argument, with nil meaning "not interactive,
just return the count without displaying a message").

> Anyway, thanks for your review!  I will write a blog post about this
> function (googling for "emacs count sloc" doesn't yield anything
> useful, let's change it! ;-) ).

Of course, you'll bump into further problems:

     (* foo bar
      * baz *)

will count as 1 lines, IIUC.  And similarly

     printf ("toto\n"); (* foo bar
                         * baz *)

will count as 2 lines.  You might want to try something like:

   (defun count-sloc-region (beg end kind)
     "Count source lines of code in region (or (narrowed part of)
   the buffer when no region is active).  SLOC means that empty
   lines and comment-only lines are not taken into consideration."
     (interactive
      (if (use-region-p)
          (list (region-beginning) (region-end) 'region)
        (list (point-min) (point-max) 'buffer)))
     (save-excursion
       (goto-char beg
       (let ((count 0))
         (while (< (point) end)
          (cond
           ((nth 4 (syntax-ppss)) ;; BOL is already inside a comment.
            (let ((pos (point)))
              (goto-char (nth 8 (syntax-ppss)))
              (forward-comment (point-max))
              (if (< (point) pos) (goto-char pos)))) ;; Just paranoia.
           (t (forward-comment (point-max))))
          (setq count (1+ count))
          (forward-line))
        (when kind
          (message "SLOC in %s: %s." kind count))))))


-- Stefan