bug#22873: Can we support multiple Cursors?

[Eli Zaretskii]

> Date:  Mon, 28 Mar 2016 20:45:07 -0700
> From:  Keith David Bershatsky <esq@lawlist.com>
> Cc:  John Wiegley <jwiegley@gmail.com>,Eli Zaretskii <eliz@gnu.org>,Marcin 
> Borkowski <mbork@mbork.pl>,Richard Stallman <rms@gnu.org>
> 
> The attached multiple_cursors_007.diff applies to the master branch as of 
> today, March 28, 2016, bearing commit 
> a30e7e12ed8465e2565dd318d921bc87f52ce18e.
> 
> mc_calc now runs from the applicable nsterm.m/w32term.c/xterm.c, instead of 
> xdisp.c.

Why is that a good idea?  You have 3 almost identical copies of the
same code, which goes against our long-time trend to have terminal
independent code only once, for easier maintenance.

>                         ((oddp current-column)
>                           (list pos "bar" [1.0 0.0 0.0])) ;; red
>                         ((evenp current-column)
>                           (list pos "bar" [0.0 0.0 1.0])))))) ;; blue

That's not how we specify colors in Emacs, not on the user level,
anyway.  I don't think I like this design.  Why not use the existing
mechanisms for specifying the cursor color?