Re: Combining face and map stuff

[Miles Bader <miles@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:
>> It sounds like he's saying it would use their union, with a
>> property-specific function used to compute that union.
>> 
>> [and that the union computation could be done at "property setting time"
>> rather than at display time, to avoid speed problems.]
>
> I'm probably missing something here: if the union is computed at
> put-text-property time, then how is this different from what we have
> now?  That union will have all the properties of the character lumped
> together, just like what we have now, right?  What am I missing?

Who knows, maybe it _could_ be implemented completely in lisp given
todays primitives ... but in order to make the layering thing work, all
the users would need to cooperate, presumably by means of a wrapper
layer.

(i.e., rename current setting primitives foo to "internal-foo", and
redefine foo in lisp to do the layering/merging stuff)

Anyway, I'm just guessing ... Stefan should answer :)

-miles

-- 
Carefully crafted initial estimates reward you not only with
reduced computational effort, but also with understanding and
increased self-esteem.         -- Numerical methods in C,
  Chapter 9. "Root Finding and Nonlinear Sets of Equations"