Re: setnu-mode and Emacs 21.

[Juanma Barranquero]

On Tue, 13 Nov 2001 21:51:03 -0700 (MST), Richard Stallman <address@hidden> 
wrote:

> A feature like this should not work by creating hundreds or thousands
> of overlays.  It should work through low-level display changes.

If creating hundreds or thousands of overlays does not work
(performance-wise), then other features that could profit from it
working right will also be slow, and won't be "fixed" by the
line-numbering-specific change you're suggesting.

For example, I tried doing a minor mode that would show in another
color/font all text that goes over the fill-column, but without
fontifying that text. I want to be able to turn it on and off with no
consequences on font-locking; asically I'd like to program with the
fill-column set to 80, and get red text every time I overstep the
fill-column, but with no other consequence. That did work with
overlays, but it was too slow so I abandoned it.

> If we can display the line number in the mode line, we can put it in
> the margin.

Is line-numbering a buffer or a window thing? How does interact with
other margin-using modules? Will it be configurable? Will it need
special printing support?

I'm not sure I'm understanding what you say. If you're suggesting the
redisplay code should be able to put line numbers in the margin, I
really thing that's not a good idea; but if what you say is that the
redisplay C code should have (lisp-side) hooks to put *anything* in
the margin, distinct and different from the current ones through text-
or overlay- properties, I sure couldn't agree more :)


                                                           /L/e/k/t/u