Re: Emacs26: Quick thoughts on display-line-numbers-mode

[Eli Zaretskii <eliz@gnu.org>]

> From: Matthew Plant <maplant95@gmail.com>
> Date: Thu, 05 Oct 2017 12:35:29 -0700
> 
> My apologies, I did not notice that line-number face existed because it
> is not part of the display line numbers group. This does exactly what I
> want.
> 
> That being said, shouldn't this face be part of the group display-line-
> number? Faces for compilation errors are part of the the compilation
> group. 

My reasoning was that this is one of the basic faces we provide, so
it's in the basic faces group.

> Being able to specify which side the line numbers appear I imagine
> would be useful for editing right to left languages.

When the paragraph direction is right-to-left, the numbers
automatically appear on the right.  You should be able to see that if
you visit TUTORIAL.he with display-line-numbers-mode turned on.

> That being said I can't find one editor that supports this feature

Well, Emacs does ;-)

> You said in a separate reply that separation between the numbers and
> the text is kept with a white-space glyph. Why not just let this be a
> buffer or mode local string specified by the user?

There's a technical problem with doing that, which I couldn't solve.
It would also slow down redisplay, while performance was high on my
priority list when working on this feature.