Re: Turning on/off tree-sitter modes

[Dmitry Gutov <dmitry@gutov.dev>]

On 23/11/2024 15:24, Eli Zaretskii wrote:
> [I've started a new thread about this.]

Nice.

>>> Another thing that seems to be missing is a command
>>> to enable just one TS-based mode, not all of them.
>>
>> How about if that's done like:
>>
>>     (setopt treesit-enable-modes '(c-ts-mode))
>>
>> Or maybe 'M-x treesit-add-enabled-mode' can be added too.
> 
> I think a command is better.

Okay. It can read the mode name with completion, and then call

   (setopt treesit-enable-modes (cons new-mode treesit-enable-modes))

> Here are the issues that are currently not handled by your patch,
> which perhaps require modifications and additions (but should probably
> be discussed first):
> 
>    . we need the ability to turn on and off selected TS-based modes,
>      and do it easily

Note that we don't have such capability currently.

I guess we could add 'treesit-remove-enabled-mode', implemented almost 
exactly like the above.

Both commands would be pure wrappers on top of the user option, so they 
don't seem to require any advance considerations. Somebody can add those 
later, or any variations on them.

>    . we should include in this feature handling of all the TS-based
>      modes in core (right now, I don't see python-ts-mode,
>      ruby-ts-mode, and csharp-ts-mode, at least)

Sure. The patch was basically abbreviated for easier reading.

>    . we should decide how to handle TS-based modes whose non-TS
>      counterparts are available as 3rd-party packages

I think we shouldn't do anything about those - they will continue to use 
the current policy for 3rd party major modes: installing a package adds 
an 'add-to-list' form to autoloads, which runs during 
package-initialize. To disable such a form, the user uninstalls a package.

>    . we should decide whether we want to modify auto-mode-alist or use
>      major-mode remapping for all the TS-based modes

I see no reason to depart from the current approach - except I've 
switched from major-mode-remap-defaults to major-mode-remap-alist (where 
the former is used) because the latter corresponds to user preferences, 
and it seems like that's the subject of our switcher.

This could also be discussed, but seems more of an orthogonal issue.