Re: [Emacs-diffs] scratch/widen-less a4ba846: Replace prog-widen with consolidating widen calls

[Alan Mackenzie <acm@muc.de>]

Hello, Stefan.

On Sat, Dec 02, 2017 at 19:03:44 -0500, Stefan Monnier wrote:
> >     (parse-partial-sexp 1 n)

> > .  I am proposing extending this property for buffers with several
> > modes and several syntax tables.  Nothing more, nothing less.

> That would potentially solve some percentage of the problems with
> MMM support.  But what about the rest?

They would clearly need other work doing on them.  Richard suggested
building something similar to narrowing for the excusive use of MMM.

> > syntax-propertize is your way of doing things, so naturally you want it
> > to become a "standard".

> I don't actually care whether the standard is my standard or not.
> What I wanted was *a* standard.

Standards are created by like-minded experts coming together, thrashing
things out, and finally agreeing on some reasonable set of compromises;
not by a lone hacker, no matter how expert, throwing something together
in his bedroom.

> > However it is not the only way of doing things,
> > and is suboptimal in several respects.

> All standards are suboptimal.

You seem to be implying that all standards are suboptimal, therefore any
standard is as good as any other.  That is palpably false.  

> The reason people use them is because the existence of a standard
> makes other things possible.

Not really.  At least, this particular standard (if such it be),
syntax-propertize, shuts off useful, even essential, possibilities.  It
is also based on syntax-ppss, which we recently agreed needed replacing
with something which does the right job.

The way you want to restrict the use of the syntax-table text property
is like having a screw driver, and only being permitted to turn it
clockwise.  That text property is a very useful general purpose tool,
something you seem to want to do away with.

> > When designing syntax-propertize, with whom did you discuss the
> > technical aspects?

> My cat.  Then I (cause at that point my cat couldn't be bothered to
> follow me to the desk) tried what we both thought might work, then
> I applied it to more modes, and a few years later it ends up working in
> *all* major modes I know (including CC-mode, tho I haven't bothered to
> make it robust enough to have a patch, knowing that you're never going
> to accept such a patch in CC-mode, even though it's mostly just throwing
> away code).

It may be possible to rebuild CC Mode to conform to this "standard", but
it would be a lot of work, the "standard" would need enhancements[*], CC
Mode would run more slowly, and its users wouldn't see any benefit.

[*] What I'm thinking of, in particular, is after buffer changes, the
syntax-propertize mechanism doesn't amend the syntax-table text
properties adquately.

>         Stefan

-- 
Alan Mackenzie (Nuremberg, Germany).