Re: cc-mode fontification feels random

[Eli Zaretskii]

> From: Daniel Colascione <dancol@dancol.org>
> CC: <monnier@iro.umontreal.ca>, <rudalics@gmx.at>, <rms@gnu.org>, 
> <emacs-devel@gnu.org>
> Date: Sat, 12 Jun 2021 01:00:22 -0700
> 
> > It is a problem given how much the current fast machines can do during
> > that time.  At 3 GHz, 30 msec of CPU time is equivalent to 100 million
> > machine instructions.
> 
> And if you count electrons, the numbers are in the trillions. So what? Who 
> cares how many machine instructions it is? What matters is the latency.

I'm saying that, given how much these machines can do in 30 msec, it
doesn't sound right that we cannot refontify 35 lines of text with all
that processing power.  It tells me that our code is either very
inefficient or does a lot of unnecessary processing (or both).

Alan thought that the performance we have is acceptable.  The numbers
I mentioned would hopefully convince him otherwise.

> > We should either find a way of making this analysis faster, or give up
> > on fontifying these two cases differently.  It is IMO unacceptable
> > that redisplay is slowed down so much by mode-specific fontifications.
> 
> This is a great example of where incorrect fontification diminishes the 
> utility of syntax highlighting more generally. If I can't trust the color 
> of a symbol to distinguish a variable declaration from a type declaration, 
> why bother fontifying as either?

I think we are saying the same, just in different words.

Do you agree that slowing down redisplay so much due to fontification
is unacceptable?