bug#64647: treesit-query-error due to a recent change to tree-sitter-javascript grammar definition

[Vincenzo Pupillo]

In data sabato 15 luglio 2023 21:16:42 CEST, Eli Zaretskii ha scritto:
> > From: Theodor Thornhill <theo@thornhill.no>
> > Cc: Vincenzo Pupillo <v.pupillo@gmail.com>,  Jostein Kjonigsen
> > 
> >  <jostein@kjonigsen.net>,  64647@debbugs.gnu.org
> > 
> > Date: Sat, 15 Jul 2023 19:54:03 +0200
> > 
> > Eli Zaretskii <eliz@gnu.org> writes:
> > >> The patch in attachment fixes both problems.
> > > 
> > > Will the patch work with the grammar libraries before the recent
> > > change?
> > 
> > It will introduce regressions, but the patch itself is a change for the
> > better, both in emacs land and in the grammar itself.
> 
> What kinds of regressions?
> 
> > I don't disagree, but I think this is a difficult problem to solve, but
> > with an easy cop-out solution that most other implementors use - just
> > refer to the last supported commit. We've had some discussions on this,
> > but IIRC we never settled on anything. Personally, I think a
> > 
> > ;;; Tree-sitter-version: bb1f97b643b77fc1f082d621bf533b4b14cf0c30
> > 
> > header may be the simplest way to at least signal some awareness
> > here. That way the auto install mechanism can pull that hash directly
> > and we can ensure some sort of compatibility checking.
> > 
> > What do you think?
> 
> I think what I wrote: that we should try to make our modes work with
> reasonably old versions of the grammars, if that is practical.  While
> in general it could be a very difficult, if not impossible, to achieve
> that, the question is whether this particular issue can be solved in
> that manner.  If it can, we should do it.
I can rewrite both patches in the same way I had patched java-ts-mode. 
Basically, there are only two changes. I think it would be useful to have a 
function to check whether grammar features are supported or not. For example, 
a specialized version of treesit-query-validate that could also be used in 
interactive mode (to simplify the development).

Do I rewrite the patches?