Re: Programming challenge: Undo

["Robert Holmgren" holmgren@xxxxxxxx]

** Reply to message from Harry Binswanger  on
Mon, 30 Jun 2008 12:28:56 -0700


> Maintain "trailing versions" of the current file, in a separate window (or
> separate launch of another iteration of Xy).

Interesting idea -- hadn't thought of that. But I still think
that managing this outside of the XyWrite realm gives the most
power. There's really a lot of "thinking" that needs to go on.
XyWrite could manage it, though. There's a program in U2 called
DUO that synchronizes two separate XyWrite processes -- some of
the techniques there could be applied to do this.

I've got a working prototype and am testing it ... does up to
998 levels of UnDo|ReDo, which ought to be enough for anybody.
And is completely unobtrusive. Zero CPU consumption, and fast.

-----------------------------
Robert Holmgren
holmgren@xxxxxxxx
-----------------------------