[luatex] Using the token_filter callback only for 'some tokens'

[Khaled Hosny]

On Fri, Feb 07, 2014 at 08:54:59AM +0000, Joseph Wright wrote:
> what's the correct approach?

Personally, I’d just work on node lists before font layout is done (so
that they are char nodes) and use attributes to mark what nodes I’m
interested in from the TeX side. This way I don’t need to worry about
macro expansion at all, and I can control where to apply the case
transformation without enabling/disabling the callback all the time.

Regards,
Khaled