Re: Programming challenge: Undo

[Bill Troop billtroop@xxxxxxxx]

I heartily agree. Windows/Mac style undo is the only thing I sometimes
instinctively search for in XyWrite and miss. Undo is particularly
well-implemented in Word 2007, with a drop down list mentioning all of
your last actions. Speaking of the difficulty of getting it to work in
XPL, why can't we get one of these great teen hackers interested in
attacking the editor binary? We could make it into a contest - - but what
would the reward be?


And speaking of which - - does anyone have the source code for Xy4?


Conceptually: undo is more difficult in XyW than in any other commonly
used modern program in that XyW is command-driven. For example, you want
to undo the ip5,5 command.


Do you undo the 'formatting command' itself or do you undo the
typing of said command? Or do you do it different according to how
the command was presented to the program? (i.e., via command line,
editing in expanded mode, or via menus) - - You have these three command
layers - - the command line - - expanded mode - - - menus - - ; and
undoubtedly there are others.


So first we have to figure out the logic of what we want to do - - it's
far from straightforward - - Carl, Robert, you must have got to that
point? - - before figuring out how to do it.