Re: CC Mode with font-lock-maximum-decoration 2

[Alan Mackenzie <acm@muc.de>]

Hello, Eli.

On Tue, Aug 09, 2022 at 14:07:33 +0300, Eli Zaretskii wrote:
> > Date: Tue, 9 Aug 2022 08:00:16 +0000
> > Cc: emacs-devel@gnu.org
> > From: Alan Mackenzie <acm@muc.de>

> > > > > Then what is the importance of these measurements of yours?

> > > > They show that an attempt to speed up CC Mode/2 should be concentrating
> > > > on the code which isn't fontification code.

> > > Please elaborate on this conclusion, because I don't think I
> > > understand how you arrived at it, based on your measurements.  With
> > > the default value of font-lock-maximum-decoration, the fontifications
> > > are also very slow, relatively to other modes.

> > I mean CC Mode with font-lock-maximum-decoration = 2, particularly.  The
> > fontification in this setup is not slow (72% of Emacs Lisp Mode's
> > speed).  The setup as a whole is not fast enough.  Therefore to speed it
> > up, fontification is not the aspect to concentrate on.

> But if we will never recommend using level 2, those conclusions are
> again of no practical value for our users.  Right?

I don't agree.  If there is some place in our documentation to do it,
then we should recommend level 2 for those, like you, who want rapid
response, and level 3 for those, like me, who want accurate
fontification.  It's a simple (or complicated) user choice.

You have stated that CC Mode with level 2 is not fast enough.  I intend
to make this (what I call CC Mode/2) faster.

-- 
Alan Mackenzie (Nuremberg, Germany).