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

[Dmitry Gutov <dgutov@yandex.ru>]

On 12/4/17 6:56 PM, Eli Zaretskii wrote:

>> His proposal is reworking prog-indentation-context.
>> CC-mode doesn't support prog-indentation-context, so it's no surprise
>> that it doesn't support this replacement= and I don't see why suddenly
>> we should first get CC-mode to support it before the replacement can
>> be installed.
> 
> Not "first", "together with", or at least "soon enough after".

That still doesn't follow.

>> Apparently, this has not been enough motivation for the last decade, so
>> I'm not holding my breath.
> 
> Well, Alan just said he will try to make that happen, so I _am_
> holding my breath.

That's wonderful. But I'm still not going to hold my breath regarding 
the time estimates. It might turn out to be fairly time-consuming.

>> There isn't any.  PREV-CHUNK is probably a good idea somewhere in some
>> cases, but we haven't found those cases yet.
> 
> But it's already in Emacs.  So the question IMO is "is it such a bad
> idea that we need to get rid of it right away?"

It's pointless: PREV-CHUNK must be followed/used by a major mode. The 
majority of the important major modes are inside Emacs (the ones used by 
ANTLR are, at least). So there won't be any real benefit to keeping it in.

On the other hand, we might get a better idea how to solve that problem 
in a different way, during the next release cycle.

> AFAIU, prog-indentation-context could support a way to nest
> restrictions, because prev-chunk could be a function.

Nobody really knows how to use this.

>> You mean we should provide patches for those codes using
>> prog-indentation-context?  Doesn't Dmitry's branch already do that?
> 
> Not for ANTLR whose latest versions are maintained outside Emacs,
> AFAIU.

The diff will be like 4 lines. I can submit it whenever, wherever you want.

>>> I don't see the incompatibilities.  Basically, you replaced prog-widen
>>> with widen,
>>
>> Actually, no.
> 
> Again, I might be missing something, but "git diff" says I'm right.

Not really. There is one place where it looks like prog-widen is 
replaced by widen, but it's inside a function that's not part of the 
indentation engine (python-indent-guess-indent-offset, despite what its 
name suggests, is called from the major mode function, not through 
indent-line-function).

The other places, inside indentation engines, feature the removals of 
prog-widen and (in one case) widen calls.