Re: how to deal with comment in a new lang mode

[Kevin Rodgers <kevin.d.rodgers@gmail.com>]

Xah wrote:
> when writing a new language mode, how can one make comment-dwim work?
> 
> i can of course code my own functions dealing with comments, but i
> think it is better to use the facilities provided in newcomment.el?
> 
> right now i have:
> 
> (defun xlsl-comment-dwim (arg)
>   (interactive "*P")
>   (let ((comment-start-orig comment-start)
>         (comment-end-orig comment-end))
>     (setq comment-start "// ")
>     (setq comment-end "")
>     (comment-dwim arg)
> 
>     (setq comment-start comment-start-orig)
>     (setq comment-end comment-end-orig)
> ))
> 
> and
> 
>   (define-key xlsl-mode-map [remap comment-dwim] 'xlsl-comment-dwim)
> 
> this works fine when typing the shortcut for comment-dwim on a empty
> line to insert comment. But doesnt work as expected when the line is
> already a comment. (it does nothing)
> 
> any advice apprecated for dealing with comments in a new lang mode.

I can't address your question, but I can suggest a minor simplification
of your current implementation:

(defun xlsl-comment-dwim (arg)
   (interactive "*P")
   (let ((comment-start "// ")
         (comment-end ""))
     (comment-dwim arg)))

This is also has the advantage of restoring the original binding of
the comment-start and comment-end variables, even if comment-dwim
signals an error.

Hope that helps,

-- 
Kevin Rodgers
Denver, Colorado, USA