Re: cc-mode fontification feels random

[Ergus <spacibba@aol.com>]

Going a bit more into this. And reconsidering tree-sitter.

As there is already a tree-sitter module package with some interesting
functionalities. (I know Eli didn't like some details in it's
implementation)

But maybe it is a good time to try to disable the cc-mode font-locking
(I don't actually know if it is possible to do that), and repeat the
scrolling benchmark only with the tree-sitter-mode and
tree-sitter-hl-mode enabled?

Just to see how it compares and how much of that approach is useful?



On Fri, Jun 11, 2021 at 03:57:10PM -0400, Stefan Monnier wrote:
>> Will Emacs 27.2 do?  If you must see results from an optimized build
>> of Emacs 28, I'll have to build one first.
>
>As mentioned, mine was not an optimized build, on the contrary.
>
>>> FWIW, I ran this same test with `sm-c-mode` (which should handle `xdisp.c`
>>> about as well as CC-mode, but solves an easier problem since it doesn't
>>> try to handle as much of C as CC-mode does (e.g. no support for K&R, no
>>> highlighting of types), nor does it try to handle C++, Java, ...), and
>>> most of the times for it are between 0.02 and 0.04.
>>
>> That is much better, but still too slow, IMO.  Think: it's the time
>> that it takes us to fontify a single windowful, only a couple of
>> dozens of lines.  Why does it take so long?
>
>For comparison, here it is for lisp/subr.el: it seems actually slightly
>slower than what I for with xdisp.c when using sm-c-mode.
>
>
>        Stefan
>
>
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>let: End of buffer
>
>