Re: master 67ab357cdcc 7/7: Support treesit-thing-settings in search functions

[Eli Zaretskii]

> From: Yuan Fu <casouri@gmail.com>
> Date: Sat, 15 Apr 2023 23:42:01 -0700
> Cc: Po Lu <luangruo@yahoo.com>,
>  emacs-devel@gnu.org
> 
> 
> 
> > On Apr 15, 2023, at 11:37 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> > 
> >> From: Yuan Fu <casouri@gmail.com>
> >> Date: Sat, 15 Apr 2023 22:54:29 -0700
> >> Cc: Po Lu <luangruo@yahoo.com>,
> >> emacs-devel@gnu.org
> >> 
> >>> Btw, Yuan: any reason you couldn't use the existing assq_no_quit here?
> >> 
> >> To be very honest I didn’t know its existence before. But safe_assq is 
> >> indeed necessary, because assq_no_quit assumes the list is not circular 
> >> and doesn’t try to detect one.
> >> 
> >> For this particular use-case I just don’t want assq to signal any error, 
> >> but I do want it to detect errors. Circular error, malformed alist, or 
> >> simply couldn’t find the key, all of these will be reported to the user as 
> >> “couldn’t find the key” (as an error). This is easier to understand for 
> >> the user and easier for me to implement (than using unwind-protect and let 
> >> assq signal).
> > 
> > OK, but please move the safe_assq function (under the name
> > assq_no_signal, I suggest) to where we have assq_no_quit, and please
> > explain the difference between them in the commentary.
> > 
> > Thanks.
> 
> For me it’s just a quick local helper function. Is it useful enough to be 
> moved to fns.c?

Yes.  If it's useful in treesit.c, chances are it will be useful in
other places.

Alternatively, if you could use assq_no_quit, and test the additional
conditions in your own code (I don't know if this is possible), that
would also be good.