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Resolving the great undo-redo quandary

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Re: Resolving the great undo-redo quandary

#21

Post by ctrlmeta »

> No, there is no undo "tree", nor any complicated graphical user interface to go with. ... You've got your undos, your redos, and that's it. The underlying data structure is strictly linear, but all edit states are preserved and reachable ...

This is exactly how Emacs works!

Emacs has worked like this since its beginning in 1980s. It was even documented in the first manual (1981):

This might seem to pile one disaster on another, but it doesn't, because vou can always Undo the Undo if it didn’t help. (page 137 of manual)

I think there needs to be some sort of computing and software history lessons. It can offer great value in the current world of software development. It will save you from the trouble of rediscovering techniques that are already in use in classic battle-tested software.

(And really? You need to invent a cheesy acronym for this? If that's what it takes to sell the obvious these days, how about SLUR - Simple Linear Undo Redo?)

Re: Resolving the great undo-redo quandary

#22

Post by cletus »

The best form of history, undo and redo I've used is on hte various Jetbrains editors. It's a feature called Local History and is insanely useful.

1. It's always on. It never requires an explicit save or commit;

2. It automatically saves any changes and timestamps them;

3. You can view the state of a file or a tree at any moment in time and then pull out that file (or tree).

4. If you do that, it becomes part of the temporal history so you can always go back.

I find this completely natural because usually when it's necessary you think "Oh I need to unwind most of what I did in the last hour" or "I changed something I shouldn't have yesterday". You're not thinking about a line (or a tree) of changes. You're thinking about times and possibly ordering ("I changed X right before I changed Y").

Re: Resolving the great undo-redo quandary

#23

Post by 323 »

cletus wrote: post #22

The best form of history, undo and redo I've used is on hte various Jetbrains editors. It's a feature called Local History and is insanely useful. 1. It's always on. It never requires an explicit save or commit; 2. It automatically saves any changes and timestamps them; 3. You can view the state of a file or a tree at any moment in time and then pull out that file (or tree). 4. If you do that, it becomes part of the…

VS Code has that feature too, but only for individual files.

Re: Resolving the great undo-redo quandary

#24

Post by onedognight »

rcthompson wrote: post #4

This is exactly how undo works in Emacs out of the box. Personally, I prefer to install the undo-tree package and manually browse through the tree of undo paths. I'm not sure why this author finds a tree unacceptable for this purpose.

Additionally, emacs will filter undo/redo’s to changes within a region. If you select a region (no new command to learn) and use undo/redo, it will only perform those that affect text completely within the region. This is a superpower that delights me each time use it.

Re: Resolving the great undo-redo quandary

#25

Post by adrianmsmith »

cletus wrote: post #22

The best form of history, undo and redo I've used is on hte various Jetbrains editors. It's a feature called Local History and is insanely useful. 1. It's always on. It never requires an explicit save or commit; 2. It automatically saves any changes and timestamps them; 3. You can view the state of a file or a tree at any moment in time and then pull out that file (or tree). 4. If you do that, it becomes part of the…

Yep, I use Apple Time Machine for much the same purpose. Once you've set it up, it's always on, you can just go back in time (the granularity is once per hour, but that's been enough every time I've needed to use it) and restore (or make a copy of) any file or folder. Saved me quite a few times when Git has let me down.

Re: Resolving the great undo-redo quandary

#26

Post by gpvos »

rcthompson wrote: post #4

This is exactly how undo works in Emacs out of the box. Personally, I prefer to install the undo-tree package and manually browse through the tree of undo paths. I'm not sure why this author finds a tree unacceptable for this purpose.

And it is exactly why I find Emacs undo so hard to work with. But maybe I will get it now I've read this article.

Re: Resolving the great undo-redo quandary

#29

Post by twobitshifter »

323 wrote: post #15

Many times I want to undo to a previous state, but then apply again a few of the changes I just reverted, basically cherry-picking from the future (from the redo stack). It would be interesting to be able to see all edits as individual patches/diffs that you can commit/discard individually. Like a mini automatic git inside the editor, automatic in the sense that every "edit" creates a commit, undo/redo move HEAD. Thi…

This is what I thought the undo redo quandary would be. The fact that you can undo an undo seems like tablestakes to me.

Re: Resolving the great undo-redo quandary

#30

Post by vitiral »

ctrlmeta wrote: post #21

> No, there is no undo "tree", nor any complicated graphical user interface to go with. ... You've got your undos, your redos, and that's it. The underlying data structure is strictly linear, but all edit states are preserved and reachable ... This is exactly how Emacs works! Emacs has worked like this since its beginning in 1980s. It was even documented in the first manual (1981): This might seem to pile one disaste…

Of course emacs implements it as just a long linked list.
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