Re: adding a standard font-lock-number-face

[Fabian Ezequiel Gallina <galli.87@gmail.com>]

2011/6/17 Stefan Monnier <monnier@iro.umontreal.ca>:
>> So long story short: isn't a good idea to add a standard
>> font-lock-number-face in order to have fine grained control on
>> font-lock and give the users the chance to customize numbers
>> decoration out of the box?
>
> I don't think highlighting tokens that are only lexically relevant but
> not syntactically relevant is a good idea.
> E.g. it's good to highlight keywords because they determine structure.
> It's good to highlight strings and comments because keywords within them
> *don't* determine structure.
> It's good to highlight identifier definitions because these are
> semantically important and they tend to be a bit like section titles, so
> syntactically meaningful.
>
> But it's not useful to highlight all identifiers, or all numbers, or all
> separators, or all infix operators, ... because that doesn't help the
> user navigate his code.
>

Thanks for the clarification Stefan, I was pretty sure there was a
good reason why it wasn't there already.

An argument I can think of for inclusion is that it seems highlighting
those kind of stuff (event operators) is really common on other
editors, so it is acceptable that people coming from other places
would expect this kind of stuff highlighted out-of-the-box. I know the
"people coming from other editors" argument is kinda weak, but I don't
see why not giving them the chance to enable that easily in a vanilla
Emacs.

Please note that I'm no expert at font-locking but I think it might be
good (and possible) to let modes to specify a higher or special level
of font-locking so this kind of things can be highlighted. Let the
default be the standard Emacs way, but giving the users the chance to
enable that special level easily. This way standard font-lock
performance shouldn't be hit.

What do you think?


Regards,
-- 
Fabián E. Gallina