Re: Tree-sitter and major mode inheritance

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> Anyway, does anyone think this is a good/bad idea? Should I go implement
>> this on css, js, c, etc? It can also be the other way around: instead of
>> having c-mode being the virtual mode, we can leave c-mode as-is, and have
>> a c-base-mode inherited by c-mode and c-ts-mode. And similarly
>> rss-base-mode, rss-mode, and rss-ts-mode.
>
> I'd prefer leaving the original modes as-is.  That should cause less
> compatibility problems, I think.
>
> Stefan, any thoughts?

To the extent that Emacs-29's new `major-mode-remap-alist` can be used
to select which mode to use, we can indeed leave the original modes
as-is.

Another argument in favor is that it's a bit tricky to make `<foo>-mode`
both the parent mode and the standard entry point: we do that for
`tex-mode` but the implementation is ugly.
[ If it weren't for this implementation problem, it would be my
  favorite choice.  So maybe the better option is to add specific support
  for that in `define-derived-mode`, where we could implement it
  cleanly and thus also fix the ugly gymnastics of `tex-mode`.  ]

OTOH it's a bit jarring to have the generic term `<foo>-mode` refer to
a specific implementation.

For that reason, my preference is for:

- `<foo>-<abstract/parent/base/common>-mode` as the shared parent.
- `<foo>-mode` as a dispatch function that calls the appropriate specific
  major mode which could be `<foo>-ts-mode`, or `cc-<foo>-mode`, or
  `<foo>-with-JSX-mode`, or ...


        Stefan