Re: How to add pseudo vector types

[Eli Zaretskii]

> From: Stephen Leake <stephen_leake@stephe-leake.org>
> Cc: casouri@gmail.com,  monnier@iro.umontreal.ca,  emacs-devel@gnu.org
> Date: Fri, 23 Jul 2021 19:00:12 -0700
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> > I fail to see the significance of the difference.  Surely, you could
> >> > hand it a block of text with changes to mean that this block replaces
> >> > the previous version of that block.  It might take the parser more
> >> > work to update the parse tree in this case, but if it's fast enough,
> >> > that won't be the problem.  Right?
> >> 
> >> tree-sitter doesn't store the previous text, so there's nothing to
> >> compare it to.
> >
> > There was nothing about comparison in my text.  You tell TS that
> > editing replaced a block of text between A and B with block between A
> > and C, without revealing the fine-grained changes inside that block.
> > This must work, because editing could indeed do just that.
> 
> I see; treat the whole block as one change. Yes, that would work, but it
> would probably be less optimal than sending a list of smaller changes;
> depends on the details.

Since TS is very fast, I think this sub-optimality will not cause any
tangible performance issues in Emacs.  And from our POV it is a good
optimization because it will minimize (and to some extent optimize)
the traffic between Emacs and TS.