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

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: acm@muc.de,  emacs-devel@gnu.org
> Date: Fri, 03 Sep 2021 18:25:36 -0400
> 
> > But it does change the result.
> 
> 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.

> > Users of `jit-lock-bounds` should definitely know the importance of
> > being "the first function".
> 
> Actually, we could refine the patch to make the ordering automatic,
> based on measurements so the users of `jit-lock-register` don't need to
> know about it.

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.