multi-modes and widen (again), was: Re: forward-comment and syntax-ppss

[Dmitry Gutov]

Hi Stefan,

I'm only now working on this. :-(

On 12/20/16 1:33 PM, Stefan Monnier wrote:

> > I really meant widen, though. Not sure what calling prog-widen in there
> > would mean, semantically, because according to the previous discussion
> > prog-narrowing was something a mixed-mode code would institute. But it's
> > down the call stack from indent-according-to-mode (via a mixed-mode aware
> > indent-line-function), not above it.
>
> Indeed, but I meant "somewhere between a call to
> indent-according-to-mode and the call to major-mode specific
> indent-line-function".
>
> The point is that the indent-line-function should not need to widen,
> although maybe the buffer is not fully widened (depending on whether
> the multi-mode system uses narrowing, maybe).

Yes, so, I've pushed a change like this into scratch/widen-less. It 
removes prog-widen, thus leaving prog-indentation-context too complex 
for the only remaining use it has left.

So I was thinking of replacing it with just a variable prog-first-column 
(and an accessor function for convenience). The CHUNKS (or, now ...REST) 
element will go away because nobody has found any practical use for it 
by now.

prog-first-column is definitely needed, though. After thinking on it for 
some time, I still haven't come up with a suitable replacement.

WDYT?

It is unfortunate that we're doing it this late in Emacs 26 development 
cycle, but if we agree on this change, it will be fairly small.