[ESS] ... when editing R documents, 'delete' key behaves as 'backspace'

[Rodney Sparapani]

Martin Maechler wrote:

>     >> I have found a solution to this problem: All I need to do
>     >> is to comment out line 173 of ess-mode.el, which says:
>     >> (define-key ess-mode-map "\177"
>     >> 'backward-delete-char-untabify) After this line is
>     >> commented out, DEL key deletes forward, the same as in
>     >> all other modes.  Does that mean that it was an intended
>     >> behavior in ESS?
> 
>     StEgl> great, thanks for reporting this.  That code has
>     StEgl> probably been there a long time, so I'd imagine that
>     StEgl> yes, its intended.  Stephen
> 
> It definitely was back then 15-20 years ago.
> But in those times, I don't think that the concept
>  of <forward deletion>  via the delete key as opposed 
>  to <backward deletion> via the backspace key
> was as (almost?) universal as now.
> 
> 
> I've not used the <delete> key in ESS (or Emacs at that)
> at all in the last 10 years or so, 
> but because of the changed "universal" behavior,
> I propose that we *drop* this behavior from ess-mode {the one
> for editing *.R, *.S, *.q,  *.SAS, ... files) in ESS.
> 
> Of course we need to hear further opinions.
> For that reason, I'm forwarding this communication to ESS-help
> hoping to get feedback.
> 
> Martin Maechler

There may be considerable bit-rot in that file.  For example, the
two previous lines, 171-172, no longer appear to be necessary either.
But, unless there is some breakage, I think we should leave 171-172
alone.  However, I agree that 173 should be changed as proposed.
I'd only add that there is no backspace key on Mac keyboards.  It
is actually labeled the delete key, but I think you have a choice
in Settings as to whether it deletes forward or backward and I think
backward is the default.

Rodney