Re: Questions about tree-sitter

[Eli Zaretskii <eliz@gnu.org>]

> From: Madhu <enometh@meer.net>
> Date: Fri, 01 Sep 2023 08:09:27 +0530
> 
> * Yuan Fu <C3EFD02D-F02F-4BE8-A6F4-A2506A9EFC90 @gmail.com> :
> Wrote on Wed, 30 Aug 2023 00:03:03 -0700:
> >> On Aug 29, 2023, at 2:26 PM, Augustin Chéneau (BTuin) <btuin @mailo.com> wrote:
> >> 1. Is there a way to reload a grammar?
> >> Emacs is pretty nice as a playground for testing grammars, but once a
> >> grammar is loaded, it won't be loaded again until Emacs restarts (as
> >> far as I know).  Is it possible to reload a grammar after modifying
> >> it?
> >
> > No, and it’s probably not easy to implement either, since unloading
> > the grammar would require Emacs to purge/invalid all the
> > node/query/parsers using that grammar.
> 
> Does else see this a fundamental problem of the infrastructure, as it
> now relates to "becoming emacs"?

I don't think the capability to unload and reload is a necessary
requirement from any Emacs feature.  In particular, unloading a
feature is not always supported in a way that leaves a clean slate.

It is a good thing to have that, no doubt.  But not a hard
requirement, IMO.  Especially when the grammar is a C library, not a
Lisp library.  People who are testing grammars are advised to use
scratch Emacs sessions which are restarted when the grammar changes.