For my own use of relative line numbers (speech recognition controlled
programming) what's important is that the line numbering matches the number
of times I'd press the up/down arrow keys or C-p/C-n to move my cursor to
the labeled line. The whole reason for me to use the feature is to make it
easier by eyeballing to predict where the cursor will land after I say "up
4", "down 7", etc. So I don't care at all about the numbering matching
physical lines in the file.

This isn't the case with any of the relative line number packages I've
tried so far with visual line mode so it'd be awesome to have a reliable
mode available. I actually filed a bug against one of the packages awhile
back:

https://github.com/Fanael/relative-line-numbers/issues/6



On Jun 24, 2017 1:15 PM, "Eli Zaretskii" <eliz@gnu.org> wrote:

> So a few people requested this feature, and I started thinking about
> its implementation.  Immediately I bumped into several issues that I'm
> not sure how to resolve, since I don't really understand how this will
> be used in Emacs.
>
> First, this makes sense only for relative line numbers, right?  If not
> I don't really understand what would be the definition of "visually
> counted first line shown in a window".  If everyone agrees, it would
> mean that the current line will have the number of zero, right?  or do
> people still want to see the "physical line number" for the current
> line in this case?
>
> Next, the only use case which I fully understand is the one with
> some of the lines folded, as in Org or Outline modes.  More
> accurately, the case where text is not displayed because it was made
> invisible by the 'invisible' property of some kind -- these lines are
> not to be counted under this mode.
>
> But that is not the only case where what is displayed does not
> correspond to buffer text 1:1.  Some text on the screen might come
> from display properties or from before- and after-strings.  These can
> include embedded newlines, and this contribute to "visual lines" Emacs
> displays.  Are these lines to be counted or not?  Should Emacs display
> something for their "line numbers" or not?
>
> We need to resolve all these and possibly other subtleties before the
> feature can be implemented.  Ideas and opinions are welcome.
>
> TIA
>
>