bug#68246: 30.0.50; Add non-TS mode as extra parent of TS modes

[João Távora]

On Thu, Jan 4, 2024 at 11:18 PM Stefan Monnier <monnier@iro.umontreal.ca> wrote:
>
> > Hmmm, this would either mean stupendous and welcome
> > simplification in eglot-server-programs
>
> In the short term, most affected packages (like YASnippet as well) won't
> benefit very much because they still need to accommodate Emacs<30.

But like I told Dmitry: if the idea is good, I guess the logic isn't
hard to implement as a package-specific hack, which is then removed
in the future.

I have to say that, practical advantages aside, I don't much fancy
this implicit derivation based on a name of a specific convention.
More than the implicit bit, it's that it only affects types or at
least would seem so.  Why can't we go to the ts modes we control
ourselves and  write in this derivation?  It's because of hookage
right? We _don't_ want  x-mode-hook to run when we activate
x-ts-mode.  Or do we?  Maybe we  do?  How exactly is inheritance
defined for major modes?  What properties are inherited?