Re: font-lock-keywords uses only facename

[Miles Bader <miles@gnu.org>]

Richard Stallman <rms@gnu.org> writes:
>     - when "compiling" the keywords, do something like
>
> 	(if (and (symbolp expr) (not (boundp expr)) (facep expr))
> 	    (list 'quote expr)
> 	  expr)
>
> That sounds like a good idea to me.  It is simple and does the job.

I wonder if the `boundp' check could result in fragile behavior though
-- if someone writes a font-lock expression depending on the above
behavior, and then later a variable gets added that uses the same name,
suddenly the font-lock expression will start trying to use the variable
value, which might be a very confusing bug to find.

Except for the standard `font-lock-...-face' variables, do we have any
idea how widespread the use of variables-pointing-to-face-names in
font-lock expressions is?

If it's extremely rare, I'd be um, less nervous (don't want to say "more
happy" :-), simply making a rule that says "you can't use variable names
there except for the standard ones", i.e., use this code instead:

   (if (and (symbolp expr) (not (memq expr standard-face-variables)))
       (list 'quote expr)
     expr)

It would be kinda ugly, less backward compatible, and less `simple', but
maybe safer and more maintainable in the long run...

-Miles
-- 
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