undo-tree VS klonk

vundo is a simpler implementation: it reuses Emacs's tree and just implements the visualisation part.

undo-tree is a reimplementation of Emacs's tree based undo, that supports a visualization.

* undo-tree LOC: 4700. https://gitlab.com/tsc25/undo-tree/-/blob/master/undo-tree.e...

* vundo LOC: 1350. https://github.com/casouri/vundo/blob/master/vundo.el

That said, the situations seems murky still: the version in ELPA is newer (0.7.5), but it's still outdated, the home page advertises 0.8.2 as the latest version. And it moved to a different repository location. And looking at its history, it seems to never have included the version 0.7.5: https://gitlab.com/tsc25/undo-tree/-/commit/5da2a7aee98393d26a93c499dc79fcf793f161e1

It’s easier to mentally map that the default behaviour undo/redo for Emacs (which is not unreasonable, just complex).

The source for undo-tree contains documentation which very effectively describes the way the library works with examples and comparisons with how Emacs does things by default: https://gitlab.com/tsc25/undo-tree/-/blob/master/undo-tree.e...

Looks like the repo is moved to https://gitlab.com/tsc25/undo-tree

While surfing the web I came across this blog post: Resolving the Great Undo-Redo Quandary.

Resolving the Great Undo-Redo Quandary\ (31 comments)

My goofy lil' homemade editor does it this way: If you go back in the past and change it, the future becomes the past. This might sound confusing, but effectively it means that the undo stack contains the actual history of "what happened". This means you can hop to any past or future state linearly with undo & redo alone. I just find this easier than navigating tree GUIs and things that aren't worth the trouble to me. It can still lead to a bit of mental gymnastics in extreme cases.

https://github.com/zaboople/klonk

Note that in theory this can cause an exponential growth of the undo/redo stacks because it makes an upside-down copy of the future when you change the past; but in practice it's never been an issue.

I was thinking of adding a feature to navigate back to "last change-the-past", which wouldn't be hard.

It at least makes more sense than most science fiction time-travel plots...