Re: Make all tree-sitter modes optional

[Dmitry Gutov]

On 15/01/2023 16:01, Eli Zaretskii wrote:
> You will
> see that where possible, just loading a TS mode modifies
> auto-mode-alist if the tree-sitter support for that mode is available,
> whereas for other modes auto-mode-alist is modified only when the mode
> is actually turned on successfully for the first time.  This is
> because some of the TS modes have their own *.el files, whereas others
> share a .el file with other modes, and so loading that file doesn't
> necessarily means the user wants to use the tree-sitter based mode.

If we *are* going to do this (make all ts mode strictly optional), I 
don't think either of this is a good idea: for a given foo-ts-mode, the 
user might already have an auto-mode-alist entry configured with another 
mode (third-party or not), and they will likely 'M-x foo-ts-mode' to try 
how well it works (or doesn't).

Having auto-mode-alist modified automatically can come as a surprise 
either way.

Note the this is different to having the auto-mode-alist entries set up 
from the outset, because the user's alterations override those.

We can drop the auto-mode-alist alterations from ts modes altogether, to 
bring them back when we do decide to enable them by default.