Subject: Re: bug#20256: 25.0.50; css-mode: filling multi-line comments

From: Stefan Monnier <[email-masked]>
Date: Sat, 18 Apr 2015 10:06:04 -0400

> Thanks again for the feedback, Stefan! An updated patch follows.

Thank you.  Looks good to me.
Maybe we should even try to move this fill function to prog-mode.el.

        Stefan

> From 839810c2fc79d64634be2d27148df9f0759e1c8b Mon Sep 17 00:00:00 2001
> From: =?UTF-8?q?Simen=20Heggest=C3=B8yl?= <[email-masked]>
> Date: Thu, 9 Apr 2015 19:09:04 +0200
> Subject: [PATCH] css-mode.el: Support multi-line comment filling

> Fixes: debbugs:20256

> * lisp/textmodes/css-mode.el (css-fill-paragraph): Support multi-line
> comment filling.
> (css-adaptive-fill): New function.
> (css-mode): Set `adaptive-fill-function'.
> (scss-mode): Set `comment-continue'.
> ---
> lisp/textmodes/css-mode.el | 23 ++++++++++++++++++++---
> 1 file changed, 20 insertions(+), 3 deletions(-)

> diff --git a/lisp/textmodes/css-mode.el b/lisp/textmodes/css-mode.el
> index d1893a3..424cdb7 100644
> --- a/lisp/textmodes/css-mode.el
> +++ b/lisp/textmodes/css-mode.el
> @@ -381,7 +381,8 @@ pseudo-classes, and at-rules."
>   (setq-local comment-start-skip "/\\*+[ \t]*")
>   (setq-local comment-end "*/")
>   (setq-local comment-end-skip "[ \t]*\\*+/")
> -  (setq-local fill-paragraph-function 'css-fill-paragraph)
> +  (setq-local fill-paragraph-function #'css-fill-paragraph)
> +  (setq-local adaptive-fill-function #'css-adaptive-fill)
>   (setq-local add-log-current-defun-function #'css-current-defun-name)
>   (smie-setup css-smie-grammar #'css-smie-rules
>               :forward-token #'css-smie--forward-token
> @@ -395,6 +396,12 @@ pseudo-classes, and at-rules."

> (defun css-fill-paragraph (&optional justify)
>   (save-excursion
> +    ;; Fill succeeding comment when invoked right before a multi-line
> +    ;; comment.
> +    (when (save-excursion
> +            (beginning-of-line)
> +            (comment-search-forward (point-at-eol) t))
> +      (goto-char (match-end 0)))
>     (let ((ppss (syntax-ppss))
>           (eol (line-end-position)))
>       (cond
> @@ -414,8 +421,11 @@ pseudo-classes, and at-rules."
>                 (paragraph-separate
>                  (if (and comment-continue
>                           (string-match "[^ \t]" comment-continue))
> -                     (concat "\\(?:[ \t]*" (regexp-quote comment-continue)
> -                             "\\)?\\(?:" paragraph-separate "\\)")
> +                     (concat "\\(?:[ \t]*\\(?:"
> +                             (regexp-quote comment-continue) "\\|"
> +                             comment-start-skip "\\|"
> +                             comment-end-skip "\\)\\)?"
> +                             "\\(?:" paragraph-separate "\\)")
>                    paragraph-separate))
>                 (paragraph-start
>                  (if (and comment-continue
> @@ -468,6 +478,12 @@ pseudo-classes, and at-rules."
>             ;; Don't use the default filling code.
>             t)))))))

> +(defun css-adaptive-fill ()
> +  (when (looking-at "[ \t]*/\\*[ \t]*")
> +    (let ((str (match-string 0)))
> +      (and (string-match "/\\*" str)
> +           (replace-match " *" t t str)))))
> +
> (defun css-current-defun-name ()
>   "Return the name of the CSS section at point, or nil."
>   (save-excursion
> @@ -504,6 +520,7 @@ pseudo-classes, and at-rules."
>   "Major mode to edit \"Sassy CSS\" files."
>   (setq-local comment-start "// ")
>   (setq-local comment-end "")
> +  (setq-local comment-continue " *")
>   (setq-local comment-start-skip "/[*/]+[ \t]*")
>   (setq-local comment-end-skip "[ \t]*\\(?:\n\\|\\*+/\\)")
>   (setq-local font-lock-defaults '(scss-font-lock-keywords nil t)))
> -- 
> 2.1.4