Re: linum.el?

[Richard Stallman]

    For instance, how can `set-window-redisplay-end-trigger' be used to
    generally and reliably trigger in the following cases?

    *) widen a narrowed region
    *) expand a collapsed thread in Gnus and similar programs
    *) expand a tree in outline-mode, allout-mode and similar modes

It isn't meant to handle those cases.  Just the case of displaying text
that was previously off the end of the window.  I thought that was the
only remaining case that needed to be handled.

    Thank you! Such a hook which reliably triggers in above cases and also
    subsumes scrolling, window resizing, and insertion of new lines can be
    very advantageous for other (new) modes as well.

The problem with the new hook is that it will trigger on
ALL editing commands, as well as scrolling.  The only thing that
won't trigger it is cursor motion.  So it seems like a very inefficient
way to handle linum.  For instance, when you insert text, its hook
will run after every self-inserting character.

Isn't that going to be painful?