Re: something like linum.el ought to be added

[Richard Stallman]

    The linum.el file can be found at:

      http://stud4.tuwien.ac.at/~e0225855/linum/linum.html

It looks interesting.  Is it efficient enough?  It reassigns overlays
to all the visible lines after every command, and that might be
painfully slow.

It might as well delete ALL the overlays it has made, rather than just
those for the visible lines.  Preserving overlays on the other parts
of the buffer won't things speed up, and could waste a lot of space
and maybe also cause slowdown by having so many overlays.

It would be much better if it worked from after-change-functions, and
reassigned overlays only for the lines that really need it.

Anyone want to work on that?

    ? The line number should be put in its own face; linum.el puts it in
      the face default.

    ? The line number should be put in the display margins.  This would
      allow better display of long lines that wrap around.  The code in
      linum.el appears to be making some attempt to do this, but doesn't
      seem to actually use the margins.

I agree those are good ideas.