Re: Aborting display. Is this possible?

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

> So I suggest to turn the table and ask: how come fontification of C
> sources is so expensive, and how can we make it faster?

Indeed, that'd be better.  But IIUC Alan has already been working fairly
hard to make CC-mode's parsing faster.  So my guess is that either it's
just really hard because of some details of the C language, or we'd need
a serious restructuring/rewrite and I don't think anyone is up for that.

> IOW, if the measurements show that redisplay takes 10% of the time,
> let's not try to optimize those 10%, but instead concentrate on the
> 90%.

There's some general pressure to improve font-locking by making it more
precise, with somewhat marginal improvements but fairly high
processing costs (pushed to the extreme, this involves passing the text
to an external toolchain that parses and type-checks and returns to
Emacs the precise highlighting info; see for example agda-mode).

So, maybe we're looking at a future where we'll need to provide some way
for delayed/asynchronous font-lock refinement.


        Stefan