Re: Question about org-emph-re

[Carsten Dominik <carsten.dominik@gmail.com>]

On May 21, 2010, at 4:46 AM, Robert Goldman wrote:

> I have been trying to make the generic exporter do fontification  
> (bold,
> italic, underline, etc.) and have fairly successfully managed to do  
> this
> by cargo-culting the code in org-latex.
>
> But I've run myself on a rock.  I can't figure out what the various
> matches are that you get when you match org-emph-re.  There are at  
> least
> 5 matches, and some may be empty, etc.  I don't /believe/ these are
> documented anywhere (or I didn't find the docs).
>
> Can anyone tell me what (match-string x) will be after a (string-match
> org-emph-re string) call?  Or tell me where to look to figure it out?
>
> If so, I think I can get the fontification to work for org-generic- 
> export.


The match groups are now documented:

http://repo.or.cz/w/org-mode.git/commitdiff/67331a2de01cabc8e5bfc0f45d901c10aecf96a2

>
> (also, emacs-lisp question --- is there some way to /clear/ all the
> registers for MATCH-STRING?  When I have been doing this, I have
> occasionally had troubles where match-string outputs from previous  
> calls
> to string-match seem to "bleed through.")

You always need to check if there is actually a match by checking the  
return value of the call.  If there was a match, then you can rely on  
the group.  If there was no match, the groups bleed through

(when (string-match ...)
    ;; here you can rely on the groups
)


(when (re-search-forward "..." ...)
    ;; here you can rely on he groups
)


HTH

- Carsten