Harking back to some old 8-bits

[Phil Carmody]

I remember the wonderful feature of being able to move a read-cursor 
somewhere on the screen, press the 'copy' key, and whatever character 
was at the read-cursor would be duplicated under the write-cursor,
and both cursors would move forward. I'd really like that feature
again (presumably 'mark' would be the read-cursor).
e.g. http://en.wikipedia.org/wiki/Image:BBC_Micro.jpeg

However, with what I'm hacking at currently (lots of closely-related 
lines of code), just the very simple function of being able to 
grab whatever character is on the line above and duplicate it on 
the current line would be great.

I'm more than a little rusty at elisp, but here's what I threw 
together in a few minutes this morning in order to achieve the 
latter:

---- 8< ----
(defun pc-dupchar-above ()
  "Duplicate character on line above cursor"
  (interactive)
  (insert (save-excursion
                 (next-line -1)
                 (buffer-substring-no-properties 
                  (point) 
                  (1+ (point))))))

(local-set-key (kbd "C-^") 'pc-dupchar-above)
---- 8< ----

It has at least one problem, namely it doesn't properly 
extend short lines if you've just come from a longer line.
(E.g. cursor down from right -->here<-- , and try to copy 
the 'r' of 'from'.)

If anyone could turn the above into something more robust,
I'd be grateful, maybe things like having a prefix count 
would be good too?

And if someone could give some advice on how to have the 
ability to treat the mark as a read cursor, and copy forwards 
from there (preferably without moving the mark, which requires 
maintaining some state about how many characters have been 
copied), that would be fantastic. Maybe there's already an 
emulation mode that has this functionality, I don't know. 

Cheers,
Phil
-- 
I tried the Vista speech recognition by running the tutorial. I was 
amazed, it was awesome, recognised every word I said. Then I said the 
wrong word ... and it typed the right one. It was actually just 
detecting a sound and printing the expected word! -- pbhj on /.