Re: Bug #22983 (syntax-ppss returns wrong result) is still open. Could we fix it before the release, please.

[Alan Mackenzie]

Hello, Dmitry.

On Wed, Jun 08, 2016 at 02:25:22AM +0300, Dmitry Gutov wrote:
> On 06/08/2016 01:48 AM, Alan Mackenzie wrote:

> > I think I'd be happy enough about it being fixed in master, if the fix
> > happens before the release.  :-).  The trouble is, if there's no
> > deadline, it'll never get fixed.

> Why before the release in particular?

Haven't I just said?  :-)  If not before the release, then when?

> If you're interested in having it fixed sooner, please look into helping 
> Vitalie in 
> http://lists.gnu.org/archive/html/emacs-devel/2016-04/msg00850.html. 
> With hard-widen, maybe we won't need syntax-ppss-dont-widen after all.

Is Vitalie still working on this (or indeed, anything else to do with
Emacs)?  I don't recall seeing him for quite a number of weeks, now.

I can't say I feel enthusiastic about "hard-widen".  I haven't looked
into it that thoroughly, but it feels a bit like an ugly hack whose
ramifications might percolate all the way through Emacs, and that might
make us regret it fairly heavily in the not too distant future.

> > Yes, I think having the binary toggle `syntax-ppss-dont-widen' purely to
> > direct the innards of the function is poor programming (since it
> > explicitly toggles a toggle inside a supposedly abstract function).

> Abstract?

Yes, abstract.  `syntax-ppss' has an specification and interface on the
one side, and an implementation on the other.  This separation is an
abstraction.  Although it might not be a very strong one, given how
users must keep "servicing" it, it is better than nothing.

> > I think an improvement would be to dispense with that toggle, and
> > have two distinct functions, one in place of
> > `syntax-ppss-dont-widen' being nil, and the other in place of
> > `s-p-d-w' being non-nil.  The latter function might usefully have an
> > extra parameter specifying the base point that parse-partial-sexp
> > should be calculated from.  That would leave quite a few options
> > open for the internal logic of the function.

> That wouldn't help in the multi-mode case, which is the primary use I 
> have in mind for syntax-ppss-dont-widen.

Why would it not help?

-- 
Alan Mackenzie (Nuremberg, Germany).