Re: bug-reference-prog-mode slows down CC Mode's scrolling by ~7%

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: acm@muc.de,  emacs-devel@gnu.org
> Date: Sat, 04 Sep 2021 09:36:04 -0400
> 
> >> It changes the overall behavior a bit, yes.  And of course, that might
> >> trigger bugs somewhere, like any other change.  But other than that, it
> >> should not change the actual final result other than how fast we get to
> >> it, no.
> >
> > I'm looking at this from the POV of someone who writes a function to
> > be registered with JIT font-lock.  They need to understand these
> > details to be able to write code which will do what they want.
> 
> Why should they?

To achieve their goals, of course.

I really don't understand why we are having this conversation.  It's
almost as if you claimed that documenting non-trivial behavior is a
bad idea, or a luxury.  But you cannot be seriously thinking that.

> This description has been valid for a while and the changes discussed
> here do not impact it at all.

Excuse me, but the jit-lock-bounds was almost completely undocumented,
until I did that a few days ago.  So what description are you alluding
to which has been valid?

> > They would still know about the automatic ordering because if some
> > other function gets put at the first place, the results will be
> > different, and that needs to be explained.
> 
> I don't see in what sense "the results will be different".
> Which results are you talking a bout?

The results of running jit-lock-functions.  those which really perform
fontifications result in faces, others result in whatever they do.