This commit includes a jj recipe for the Git command table that is
approximately equivalent to Git's checkout command, which can be used to
examine source code at named revision or branch. This is indispensible
for learn-by-doing types who are curious how to remap Git usage back
onto jj with minimal effort.
Closes https://github.com/jj-vcs/jj/issues/7189
Colocated repos have some advantages and some disadvantages. On the
whole, I think making Git repos colocated by default is a better
trade-off, especially for new users. With the `git.colocate` setting,
(experienced) users can easily change this according to preference.
A non-exhaustive list of pros and cons of colocated repos:
pros:
* Many code editors show the changes one is currently working on based
on Git's "dirty worktree".
* There are a lot of tools that integrate with Git which don't work at
all in non-colocated repositories.
* There are a lot of Git features that Jujutsu doesn't have yet. When
users ask for them, the answer is usually: "Just colocate your repo
and run git directly for now." It's a strength that Jujutsu can focus
on what makes it special and not have to rush the reimplementation of
every niche feature of Git. Examples: `git rebase` tracking file
renames, `git bisect`, `git tag`, `git range-diff`, submodules.
cons:
* Jujutsu performs worse in colocated repositories with lots of refs,
because of the automatic `jj git import`.
* Colocated repos make branch@git references show up in Jujutsu output,
which is usually just aesthetically displeasing or possibly even
confusing to inexperienced users.
* Interleaving jj and (mutating) git commands can lead to confusing
situations. Examples:
* Creating a commit with git instead of jj will often leave a
duplicate "work in progress" commit in Jujutsu's log.
* Some IDEs periodically run `git fetch` in the background. This can
lead to conflicted branches and divergent change IDs, something many
people struggle with.
This is the natural counterpart of `jj undo`. Adding `jj redo` closes
the last gap in functionality to the "undo" features of typical GUI
applications. This is much more intuitive to new users and useful than
the previous undo semantics. (Which are preserved as `jj op revert`.)
Related feature request "jj undo ergonomics":
https://github.com/jj-vcs/jj/issues/3700
This paves the way for the semantics of `jj undo` and `jj op revert` to
evolve independently. `jj op revert` is going to stay the low-level
command to apply the inverse of any operation. The new name is
consistent with `jj revert`, which applies the inverse of a commit.
`jj undo` on the other hand is planned to become a higher-level command,
which is more similar to, say, Ctrl+Z in typical GUI applications.
Running `jj undo` repeatedly will revert progressively older operations,
allowing the user to walk backwards in time. At the same time, `jj undo`
will lose the abilitly to revert arbitrary operations, to keep its
semantics simple and intuitive.
Related feature request "jj undo ergonomics":
https://github.com/jj-vcs/jj/issues/3700
