Re: Suggested experimental test

[Gregory Heytings]

> > > > > I use C-o (usually followed by C-n) many times a day, instead of 
> > > > > <Enter>, in order to suppress re-indentation of the current line in 
> > > > > cases where that re-indentation will be incorrect for my purposes**.
> > > >
> > > > Oh, I see -- it's useful as an alternative to `RET' exactly when 
> > > > re-indentation does the wrong thing?
> > >
> > > Yes, but not only that -- it doesn't move point to the next line, 
> > > unlike RET.
> >
> > Why should a control key must be reserved forever for that very 
> > specific purpose, and for that very specific purpose only, in the 
> > default Emacs bindings?
>
> Opening an empty line is a very useful editing primitive, not unlike 
> going to the next line with RET.

I'd bet it is useful, as it is, only for 0.5% of Emacs users, perhaps even 
less.  No other editor I know has that feature.  And I'd bet that 90% of 
those 0.5% would be happier with a better open-line primitive, for example 
one which can be called when point is in the middle of a line, like "o" 
and "O" in vi.  The discussion showed that those who use it use it at BOL, 
and that it wasn't used alone, but as part of a sequence, for example C-a 
C-o or C-o C-n.  Nobody even mentioned the fact that open-line uses the 
fill-prefix and the left-margin.

As I said, an improved version of that command could for example be put on 
M-RET.  Here's an attempt:

(defun smart-open-line (&optional arg)
  (interactive "*p")
  (when (> arg 0)
    (beginning-of-line)
    (let ((p (point-marker)))
      (dotimes (_ arg) (insert "\n"))
      (goto-char p)))
  (when (< arg 0)
    (setq arg (abs arg))
    (beginning-of-line)
    (forward-line 1)
    (dotimes (_ arg) (insert "\n"))
    (forward-line -1)))
(global-set-key (kbd "M-RET") 'smart-open-line)

And even assuming that it is useful as it is, that doesn't answer the main 
question: why should a control character key be reserved forever for that 
very specific purpose, and for that very specific purpose only?

> Trying to change that will always cause staunch resistance, especially 
> when the purpose for which this is done is vague and not perceived as 
> important enough by enough people.

I could have clarified the purpose indeed, but the risk would have been to 
start two parallel discussions.