Backspace does not erase in stdout

[Chris Angelico]

On Wed, Dec 7, 2011 at 12:21 AM, Rick Johnson
<rantingrickjohnson at gmail.com> wrote:
> *Wise Observer Speculates:* Why on earth are we "21st century slaves"
> to an archaic mid 20th century technology that punches holes in paper
> tape? Anyone?
>
>>>> isinstance(Progress, None)
> True

I'm not sure. Let's see...

* Manned, powered, heavier-than-air flight: A hundred years.
* TCP/IP: Thirty years.
* Sliced bread: Eighty years. (What was the greatest thing BEFORE sliced bread?)
* The English language: A few hundred, depending on how you count

Why are we still eating sliced bread on board aeroplanes while posting
in English on internet forums? Clearly we've made no progress since
then. What language and communication protocol do you propose for the
new python-troll-list?

Getting back to the point though...

The use of 127 for DEL is a consequence of the exact technology of
paper tape. However, the question of whether BS is destructive or not
is separate. Should it parallel other characters (draw character at
cursor then advance cursor, vs retard cursor then erase character at
cursor), or should it parallel cursor movement (eg carriage return,
line feed, vertical tab)? If your BS is defined nondestructively, you
can implement the destructive version with three characters; if it's
defined destructively, you can't implement a nondestructive without
some fiddliness (some systems use characters 28-31 for cursor
movement).

ChrisA