On Fri, Dec 27, 2024, 9:25 AM Daniel Colascione <dancol@dancol.org> wrote:

>
>
> It's a shame there's no way to write TS grammars in plain elisp. I figure
> vendoring both the source and the generated code would be best, as it'd
> allow building Emacs anywhere but still make it convenient on systems with
> needed tools (JS runtime, Rust, etc.) to update and modify the grammar. As
> with any scheme involving checking in generated outputs, the source and
> output can get out of sync, but I think there are build time guardrails we
> can build to make sure it doesn't happen.
>

I looked into this last year.  The tree-sitter library provides a parsing
engine that references a fairly standard LR type parsing table in binary
form.  I got stuck in adding a generic primitive functionality for reading
and writing arbitrary binary data structures based on a data description
DSL, since I wouldn't want to tie the interpreter core to the data
structures of an external, dynamically-loadable library.  But, I wasn't
sure such an extension would be accepted into emacs, as I am not an expert
on the possible security implications.

Other than that, emacs already has the code for calculating (LA)LR parsing
tables in the semantic packages.  The tree-sitter grammar compiler may have
additional logic for providing multiple starting symbols, but the parsing
engine should still function with a classic parsing table.

Lynn