Re: Native display of line numbers, improved

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@IRO.UMontreal.CA>
> Cc: emacs-devel@gnu.org
> Date: Mon, 26 Jun 2017 12:12:34 -0400
> 
> Oh, I didn't mean to use that variable.  I was just explaining that Alex
> request to "grow-only" seems to work fairly well to provide "mostly
> constant width" without having to scan the whole buffer upfront.

Yes, the idea is fairly clear ;-)

> How to provide "grow-only" (i.e. where to store the previous-width info)
> is not something I've thought about, but maybe it can be kept as
> a window-local information, reset whenever we set-window-buffer.

A variety of ways exist, but each one comes with some, albeit minor,
disadvantage and added complexity.  So I'd like first to see whether
this is needed, on top of what's already there.

Basically, I'd like to keep the feature as simple and lightweight as
possible, leaving the 20% percent to local customizations, rather than
forcing everyone to bear the price.