bug#60511: 29.0.50; treesit-ready-p should not emit warning by default

[Eli Zaretskii]

> From: Yuan Fu <casouri@gmail.com>
> Date: Sat, 7 Jan 2023 17:31:16 -0800
> Cc: Stefan Kangas <stefankangas@gmail.com>,
>  60511@debbugs.gnu.org,
>  Eli Zaretskii <eliz@gnu.org>
> 
> 
> Juri Linkov <juri@linkov.net> writes:
> 
> >>>> This currently emits a warning if the ruby grammar is not installed:
> >>>>
> >>>>     (treesit-ready-p 'ruby)
> >>>>
> >>>> I think it should *not* emit a warning, as no other predicates in Emacs
> >>>> do (e.g. `featurep', `integerp', etc.).
> >>>>
> >>>> It could have an optional flag to emit a warning, if there's a strong
> >>>> need for that.  But personally, I'd rather see a new function for that.
> >>>>
> >>>> I also don't see much need for the `message' symbol as the second
> >>>> argument, so I'd simplify the API by dropping that part.  It's currently
> >>>> unused in our tree.
> >>>
> >>> Like the argument NOERROR of `require', the argument QUIET of 
> >>> `treesit-ready-p'
> >>> could do the same.
> >>
> >> Maybe rename it to treesit-check-readiness?
> >
> > I think treesit-ready-p already is a good name.
> > We just need to support more values in its argument QUIET,
> > with a new value that does nothing in case of an error,
> > and just returns nil.
> 
> It already has such option: if QUIET is t, treesit-ready-p returns nil and 
> don’t emit anything.
> 
> I can make treesit-ready-p not emit any warning by default, and change
> the quiet parameter to WARN, and accept either 'warn or ‘message.
> 
> Basically:
> 
> (treesit-ready-p lang) => t/nil
> (treesit-ready-p lang 'warn) => t/emit warning
> (treesit-ready-p lang 'message) => t/message
> 
> Eli, WDYT?

I think the default should be to emit a warning, like we do now.  We
should support the main use case of the user turning on a TS mode when
the required libraries are not installed or incompatible with our
requirements.  Silently doing nothing in that case is not TRT.

No objections from me to extend the QUIET argument other than that.