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Surprised this is done in Rust. I could never imagine not doing the v1 of something like this in Python or similar, to be able to change things quickly. Maybe t

by swah 3y ago

Surprised this is done in Rust. I could never imagine not doing the v1 of something like this in Python or similar, to be able to change things quickly. Maybe the design was very clear on the person's mind.

bryanlarsen 3y ago
Rust is a fabulous language for refactoring. Strong types and complete matching make it almost completely impossible to miss a spot when making a change
dontlaugh 3y ago
I feel the opposite way. Even though Python is the language I’ve used most, I wouldn’t want to use it for something with a lot of uncertainty and that will suffer many changes. Type systems make it so much easier to change things early on without breaking everything. I’d probably pick F# or similar.
- gsuuon 3y ago
  There actually is a similar project in F#: https://github.com/ScottArbeit/Grace https://github.com/ScottArbeit/Grace
Smaug123 3y ago
Python certainly lets you change things quickly, because it does not let you automatically enforce any invariants; this is why it lets you get into such extraordinary inconsistent states so easily! I personally could never imagine trying to make a jigsaw out of jelly because "it's v1 and I'll make v2 properly".
martinvonz 3y ago
The current DVCS solution at Google is based on Mercurial, which is written in Python. Having worked on that for many years, I didn't want to write jj in Python. We've had problems with the performance of the current solution. Also, as others have said in sibling replies, refactoring Python is not fun due to lack of static types (I know it's gotten better).
aseipp 3y ago
There are other advantages aside from the static types debate in the other replies. The need for efficient version control systems is a constant and ongoing battle; you can pick the right data structures (for example, Git's issues with large files are more of a data structure problem than one of raw efficiency) but at the end of the day Python will often be behind on raw performance. Rust will hopefully let us embed the Jujutsu libraries inside other languages, something you can only achieve today in Git with something like libgit2. Finally, a lot of the infrastructure we get to use, like nextest and cargo-insta are simply fantastic even if I have my qualms about Cargo. Most of the developers (some of them being former Mercurial and Git developers) including me generally seem to like it. Based on my own experience, I think it's a pretty excellent choice, but I'd be a bit biased as a die-hard Haskell/C programmer for something fast with types.
mhh__ 3y ago
I'm not particularly productive in python. The code gets shat out faster but it's a comparatively weak language for capital-P Programming — lack of types means repeating and checking yourself a lot.

by swah 3y ago

bryanlarsen 3y ago

Rust is a fabulous language for refactoring. Strong types and complete matching make it almost completely impossible to miss a spot when making a change

dontlaugh 3y ago

I feel the opposite way. Even though Python is the language I’ve used most, I wouldn’t want to use it for something with a lot of uncertainty and that will suffer many changes. Type systems make it so much easier to change things early on without breaking everything. I’d probably pick F# or similar.

gsuuon 3y ago
There actually is a similar project in F#: https://github.com/ScottArbeit/Grace https://github.com/ScottArbeit/Grace

Smaug123 3y ago

Python certainly lets you change things quickly, because it does not let you automatically enforce any invariants; this is why it lets you get into such extraordinary inconsistent states so easily! I personally could never imagine trying to make a jigsaw out of jelly because "it's v1 and I'll make v2 properly".

martinvonz 3y ago

The current DVCS solution at Google is based on Mercurial, which is written in Python. Having worked on that for many years, I didn't want to write jj in Python. We've had problems with the performance of the current solution. Also, as others have said in sibling replies, refactoring Python is not fun due to lack of static types (I know it's gotten better).

aseipp 3y ago

There are other advantages aside from the static types debate in the other replies. The need for efficient version control systems is a constant and ongoing battle; you can pick the right data structures (for example, Git's issues with large files are more of a data structure problem than one of raw efficiency) but at the end of the day Python will often be behind on raw performance. Rust will hopefully let us embed the Jujutsu libraries inside other languages, something you can only achieve today in Git with something like libgit2. Finally, a lot of the infrastructure we get to use, like nextest and cargo-insta are simply fantastic even if I have my qualms about Cargo. Most of the developers (some of them being former Mercurial and Git developers) including me generally seem to like it. Based on my own experience, I think it's a pretty excellent choice, but I'd be a bit biased as a die-hard Haskell/C programmer for something fast with types.

mhh__ 3y ago

I'm not particularly productive in python. The code gets shat out faster but it's a comparatively weak language for capital-P Programming — lack of types means repeating and checking yourself a lot.