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

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> 99% of the multi-major-modes out there use narrowing for that purpose,
>> and in practice it doesn't restrict other uses of narrowing.
> If that were the case, there would be no restrictions on a major mode
> widening and narrowing.  From what I understand about the new proposal,
> your last paragraph is false.

Depends what you expect "use" to mean.  For me "call widen"
doesn't qualify as "uses narrowing".  So I stand by what I said.

> By the way, what about that other 1% of multiple-major-modes?  How do
> they work?

Multiple buffers (either by copying text to/from side-buffers, or by
use of indirect-buffers).

>> I've opposed the use of narrowing for that in the past, but the evidence
>> against that opposition is overwhelming.  Let's do that and move on.
> No.  The evidence is that these modes can only work with specially
> adapted major modes,

Right.  And use of narrowing is the way that makes this adaption
simplest (in many cases it becomes trivial.  See for example how easy
it's been to implement mhtml-mode).

I don't know of any MMM solution which provides a satisfactory user
experience and at the same time works for all major modes,
without any need to tweak them at all, no matter how twisted is the
major mode's code.


        Stefan