Re: mode line: 1) indicate region size, if active; 2) highlight column # if > limit

[Juri Linkov]

> I liked the column highlight feature, but the region size
> feature didn't seem very useful to me.
>
> Would someone please install the column highlight feature?
>
> If several people try the region size feature, and say they find it
> useful, then I will reconsider it.

I suggest to install both features, but disable them by default.

There could be new modes to enable each of them.  Unfortunately,
currently there are no convention of adding a common prefix to
the name of the mode affecting the mode line, so from the name
of mode it's impossible to see that it changes the display of the
mode line.  Such modes could have a prefix like `modeline-', e.g.:

modeline-line-number-mode (current line-number-mode)
modeline-column-number-mode (current column-number-mode)
modeline-buffer-size-mode (current size-indication-mode)
modeline-region-size-mode (new mode)
modeline-column-limit (new mode)

Also I suggest to fix the column highlight feature to highlight only
the column number in the combined format "(%l,%c)", not the line number.
And also to change its face definition `modelinepos-column-warning' to
inherit from `font-lock-warning-face'.

-- 
Juri Linkov
http://www.jurta.org/emacs/