[Coco] BASIC09 - How good is it?

[Luis Antoniosi (CoCoDemus)]

>
> Which needs one more, a CTRL+U to undo what you just did, in case that
> wasn't what you wanted to do.  Say 5 levels deep if memory can be found to
> save that much data.
>
>
Undoing is not that simple when you can remove or duplicate entire lines.
If you look a text editor on PC it just save a full text instance for each
undo, what is not possible in the short coco's memory.

So for each action I should be able to undo-it , gets complicated when
lines are split or merged. It's not a $0D character in the middle we are
talking about but two separated double linked string lists that are merged
and possibly relocated somewhere else in the memory. Also deleted lines
should be kept for a while lingering somewhere, what increases a lot the
complexity.