Re: /srv/bzr/emacs/trunk r101338: * lisp/emacs-lisp/syntax.el (syntax-ppss): More sanity check to catch

[Eli Zaretskii <eliz@gnu.org>]

> From: Michael Welsh Duggan <mwd@md5i.com>
> Date: Sat, 15 Feb 2014 00:52:58 -0500
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > My point is that we should come up with a list of the requirements,
> > and then design and implement the infrastructure which will support
> > them, instead of implementing multi-mode buffers by piggybacking
> > existing infrastructure, which was never designed to support such
> > features.
> 
> Although I might be setting the cat among the pigeons, I thought I'd
> throw out an example of a possible infrastructure change along these
> lines.
> 
> What if we could have a display property (or something like a display
> property) that, rather than displaying a string or an image, displays
> (a portion of?) another buffer.

That's implementation, not requirements (I'm sure you know that).
While it is possible that it will allow what is needed, specifying
implementation first does not allow to come up with alternative
implementation ideas that satisfy the same requirements.  E.g., what
you suggest would require a serious surgery on the design of the
display engine, and the question remains whether such a surgery is
indeed the best or the only way to go.  (Personally, I hope not.)

So I really think we should define the requirements first.