Document absence of "undo" functionality

[benghancock]

I'm new to mined and it seems to be an exceptional editor. There's one aspect that I've found quite surprising: the apparent absence of "undo" functionality. Given that a lot of thought has gone into the program's design, I imagine this omission is intentional. Is there a workflow, philosophy, or other reason behind the absence of "undo"? May I recommend documenting this, so that the uninitiated have some introduction to this way of doing things? To a newcomer like myself, it feels like living on the edge 😄

Conversely, have I just missed something? I don't think so. I tried starting mined via Emacs-compatibility mode, typed some text and then hit the usual "Undo" key chord, and was greeted with the message "Undo not implemented".

Thanks!

[mined]

Thanks for raising this issue. No, there is no intentional "non-undo" philosophy. I have in fact thought about this feature and it's on my (very long) "todo" list. The problem is simply it's likely to be pretty high effort. And it's a design issue in the first place; should undo work per character/word/line? I think emacs has a medium approach (per word mostly). Would undo without redo be a good initial solution? Should implementation use "undo records" (emacs) or a replay approach?

[benghancock]

Thanks for the quick response! That's good to know.

I'm not sure if this is helpful (and I don't have expertise in this area), but I wonder if it's useful to explore the approach to undoing employed by Rob Pike's sam text editor. I'm reminded of it mainly because sam, like mined, also moved beyond the traditional line-oriented approach of other editors with structural regular expressions. Granted, the architectures are likely quite different, but I thought I'd at least mention it.

Reference: http://doc.cat-v.org/plan_9/4th_edition/papers/sam/ (see "Doing and Undoing").