I’ve looked at jj, but couldn’t make sense of the proposed benefits. I always stage individual files and never the entire working directory, so I’m confused how it improves that over git.
I've not tried jj yet so I can only speak to impressions, and those impressions appeal to me a lot. My understanding is that jj amends all the changes in _now_ so there's only one place where changes live: the commit graph. No index, no uncommitted worktree. Just commits. And then jj supposedly gives you a lot more freedom to move through and mutate the commit graph directly, rebasing dependent work for you automatically.
So instead of having to `git add -p` several times to pick apart changes from the worktree, the worktree always goes into the graph and you can `jj split` to pick them apart after.
jj split # split latest commit into two
jj edit @- # go back one
jj describe # change message
jj split # whoops, insert commit in the middle
jj edit @+ # move forward again
$EDITOR myfile # do some changes
jj st # amend the changes and show status
jj edit def # jump elsewhere in the graph
jj squash # put two commits together and auto-rebase its descendants
jj new abc # start working after latest
# etc etc
I confess I'm still pretty new to git. I haven't had a very long time to wed myself to git's index and its presence makes me do extra ceremony that I resent whenever I want to polish my graph for my personal projects.
The main difference, it seems, is workflow: git's "prepare then commit" vs jj's "commit then revise".
Currently I do make use of `git add -p` just like grandparent, but I also feel a psychological burden: I will often leave like 3 or 4 separate 2-line changes in the worktree because I don't wanna bother with the ceremony right now, but my perfectionism also resists me putting a lump commit. That's jj's main appeal to me. It amends my work in, then supposedly let's me sculpt it when I'm ready with less of that ceremony.
In addition to my other comment as you wrote you are not familiar with Git yet, some comparison to these commands. You can be in a commit in JJ, while in Git, you are always outside.
'jj edit' seems to correspond to 'git checkout', '@-' is '@~'. '@+' is not possible in Git, because a commit can have an arbitrary amount of children, Git might not even know about, not sure how JJ does this. @~5 is the 5th ancestor, @^5 is the fifth parent, @{5} is this ref five actions ago. This is the ref-log, which you can look at with 'git reflog' or 'git log --reflog'. 'master@{37.days.ago}' also works.
'jj split': use 'git commit --amend' and unselect changes or 'git reset --soft' to an older version, recommit the first part and then take the original commit on top. A git commit consists of a state, not of a diff so putting some commit on top of another that already contains part of the changes results in splitting the former.
'jj describe': 'git commit --amend'
'whoops, insert commit in the middle': just commit
'jj squash': either 'git reset --soft @~2' then 'git commit -c/C' or 'git reset @~' then 'git commit --amend' or 'git rebase' with squash or fixup. The later is possible from some other commit by using 'git commit --fixup' or even 'git absorb' (I think also exists in JJ).
Working in a detached state is fine, but you might want to add a ref (branch or tag, or something else) when you are finished, otherwise Git will eventually garbage-collect them (defaults to 4 weeks to 90 days depending on how you access the commit). You can push just fine to a remote, just specify the branch, i.e. 'git push origin @:branch'. You can also push to local branches to update them without checking them out with 'git push . @~7:feature/something'. Don't use pull, it is stupid, merge when you want to merge, rebase when you want to rebase, but don't do it implicitly as part of fetch.
Ask, if I glossed over something and shall elaborate.
ekipan|2 months ago
So instead of having to `git add -p` several times to pick apart changes from the worktree, the worktree always goes into the graph and you can `jj split` to pick them apart after.
ekipan|2 months ago
The main difference, it seems, is workflow: git's "prepare then commit" vs jj's "commit then revise".
Currently I do make use of `git add -p` just like grandparent, but I also feel a psychological burden: I will often leave like 3 or 4 separate 2-line changes in the worktree because I don't wanna bother with the ceremony right now, but my perfectionism also resists me putting a lump commit. That's jj's main appeal to me. It amends my work in, then supposedly let's me sculpt it when I'm ready with less of that ceremony.
1718627440|2 months ago
'jj edit' seems to correspond to 'git checkout', '@-' is '@~'. '@+' is not possible in Git, because a commit can have an arbitrary amount of children, Git might not even know about, not sure how JJ does this. @~5 is the 5th ancestor, @^5 is the fifth parent, @{5} is this ref five actions ago. This is the ref-log, which you can look at with 'git reflog' or 'git log --reflog'. 'master@{37.days.ago}' also works.
'jj split': use 'git commit --amend' and unselect changes or 'git reset --soft' to an older version, recommit the first part and then take the original commit on top. A git commit consists of a state, not of a diff so putting some commit on top of another that already contains part of the changes results in splitting the former.
'jj describe': 'git commit --amend'
'whoops, insert commit in the middle': just commit
'jj squash': either 'git reset --soft @~2' then 'git commit -c/C' or 'git reset @~' then 'git commit --amend' or 'git rebase' with squash or fixup. The later is possible from some other commit by using 'git commit --fixup' or even 'git absorb' (I think also exists in JJ).
Working in a detached state is fine, but you might want to add a ref (branch or tag, or something else) when you are finished, otherwise Git will eventually garbage-collect them (defaults to 4 weeks to 90 days depending on how you access the commit). You can push just fine to a remote, just specify the branch, i.e. 'git push origin @:branch'. You can also push to local branches to update them without checking them out with 'git push . @~7:feature/something'. Don't use pull, it is stupid, merge when you want to merge, rebase when you want to rebase, but don't do it implicitly as part of fetch.
Ask, if I glossed over something and shall elaborate.