Re: Suggested experimental test

[Gregory Heytings]

> C-o is bound where it is because when Emacs was written, someone -- most 
> probpobly RMS -- bound it there, so it isn't really a historical 
> accident but rather an active design decision. There is also a reason 
> why C-x C-o where it is.

I digged further in my archives.  In case some are interested:

As most of you know, the original Emacs was written in TECO.  C-o was a 
command of TECO's real-time editing feature (which was entered with C-r), 
which was imported into Emacs.  The purpose of C-o in TECO was to optimize 
redisplay: when point on in the middle of a non-empty line, C-o F O O 
required less redisplay than F O O RET.

C-o in the original Emacs didn't quite do what C-o now does: the line(s) 
created by C-o were "eated" by the text that was inserted.  In other 
words, RET in the line(s) created with C-o did not push the next lines 
down, it went on the next created line (if any).  In other words again, 
let's assume the following initial situation:

 A
|D
 E

where | is the point.  After C-u 2 C-o B RET C RET, the buffer was now:

 A
 B
 C
|D
 E

In other words again, C-o was meant to "create some blank space on the 
screen" (not in the buffer) to optimize redisplay.

Do you now see the "historical accident"?