Re: New optimisations for long raw strings in C++ Mode.

[Eli Zaretskii]

> Date: Wed, 10 Aug 2022 16:50:43 +0000
> Cc: gregory@heytings.org, larsi@gnus.org, emacs-devel@gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> Hello, Eli.
> 
> On Wed, Aug 10, 2022 at 19:35:58 +0300, Eli Zaretskii wrote:
> > > Date: Wed, 10 Aug 2022 16:23:27 +0000
> > > Cc: gregory@heytings.org, larsi@gnus.org, emacs-devel@gnu.org
> > > From: Alan Mackenzie <acm@muc.de>
> 
> > > CC Mode has not been doing anything wrong in accessing the buffers it
> > > controls.  The idea that one should access only the characters in the
> > > (BEG END) supplied by fontification_functions (and jit-lock) is false.
> > > It has no basis in rationality.  And in fact, standard font-locking
> > > itself accesses (via syntax-ppss) all character positions from BOB to
> > > BEG.
> 
> > You seem to disagree with a major idea of the design of the Emacs
> > display engine.
> 
> I don't think I do.  I think you mean the idea of lazy fontification,
> though you haven't been specific.

No, I mean the idea that redisplay processes only a small amount of
buffer text around the window.

> This fontification is all about fontifying restricted areas of the
> buffer.  There is no principle that one shouldn't look at distant
> portions of the buffer as need be, to facilitate the fontification of
> the restricted area.

You are contradicting yourself.

> This is absolutely necessary correctly to fontify (long) strings and
> comments, for example.

Only if you assume the most simplistic processing.