Re: Reliable after-change-functions (via: Using incremental parsing in Emacs)

[Dmitry Gutov]

On 01.04.2020 05:28, Eli Zaretskii wrote:
> > Cc: address@hidden, address@hidden, address@hidden,
> >   address@hidden
> > From: Dmitry Gutov <address@hidden>
> > Date: Tue, 31 Mar 2020 22:50:43 +0300
> >
> > > > (benchmark 1 '(progn (find-file "src/xdisp.c") (goto-char (point-max))))
> > > >
> > > > => Elapsed time: 1.940401s (0.376140s in 6 GCs)
> > > This doesn't measure the redisplay (which happens after the above
> > > command returns).
> >
> > Which means that the current state of affairs is even slower.
>
> No, it means that whatever delay we will have with parsing the entire
> buffer is _in_addition_ to whatever you measured.

Probably not. IIUC, most of this 1.2 measured delay is CC Mode doing the 
preliminary parsing. That phase would be replaced by TreeSitter's full 
buffer parse, which supposedly takes a comparable amount of time.

The redisplay phase will most likely be faster because by then the 
correct AST is available, and computing highlighting based on it is 
supposedly something that TreeSitter does quickly and well.