3 ms·

What are you talking about?? Bun in Rust is a port, almost exactly the same code base on a different syntax. The architecture did not change at all. Amazing how

by brabel 5mo ago

What are you talking about?? Bun in Rust is a port, almost exactly the same code base on a different syntax. The architecture did not change at all. Amazing how people comment without even knowing what they are talking about.

soraminazuki 5mo ago
Very amazing indeed. Here you are making bold assumptions about a huge pile of code not a single human being has ever read in any meaningful amount.
- brabel 5mo ago
  The only assumption you need to make is how the process went about, which was described by Jarred on a HN comment when the PR was first discussed: they had prompt that described exactly how things should be translated, for each "pattern" they were using in Zig, an appropriate equivalent was described in Rust. Zig and Rust are not that different, both are system languages and things can be done similarly in both languages, so architecture-wise I would think the exact same thing would work fine. I am not sure whether the LLM actually wrote a transpiler which just followed the rules, or if it did the job itself, since that information is not public yet, as far as I know, but my guess is that the LLM wrote a transpiler to do the job, then reviewed/fixed compilation issues, then fixed tests. And I'm pretty sure some human interaction was part of that as well.
  - soraminazuki 5mo ago
    So now you've gone from making assumptions to making up wild stories territory. Well, the commit granularity isn't that of transpiler passes, and more importantly, it's completely irrelevant to how the majority of the code hasn't even been read by anyone.
  - kikimora 5mo ago
    >The only assumption you need to make is how the process went about, which was described by Jarred This is not how the process went. This is how Jarred thinks it went, a huge difference. >my guess is that the LLM wrote a transpiler to do the job My guess is different. I think one agent translated code, another compiled it, feeding errors back into translator to fix. Then last agent modifies code to fix tests. All governed by a set of md files.
thayne 5mo ago
Zig and Rust are significantly different languages. If bun has a good architecture in zig (which I don't know if it does or not), that doesn't necessarily mean it had a good architecture for rust. A direct translation of zig code would probably result in pretty unusual rust code, and probably a lot more unsafe usage than if it had been originally written in rust.
- adampunk 5mo ago
  I don’t really understand this objection. For every tool that I use, am I supposed to divine the best underlying language for it and then determine whether or not it is written in that language? Don’t I have better things to do?
  - kikimora 5mo ago
    Because of borrow checker you would build data structures differently in Rust compared to Zig. Automated translation simply maps Zig constructs onto unsafe Rust code. I have no idea how feasible it is to go from totally unique way of using Rust to mimic Zig to idiomatic Rust.
    - adampunk 5mo ago
      I understand that. That’s a specific example of an inaptness moving from one language to another. That’s not what I’m talking about. I am asking if we are expected to understand this hypothetical condition about all possible tools that we use. Should I have to worry that something is written in Python when it should’ve been written in C? It just seems like that in order to have a big concern here, I had to be really invested in what language Bun used. I guess the whole matter makes more sense if people are REALLY mad about something else and the choice of language is supposed to serve as a more respectable thing to be mad about.
  - fragmede 5mo ago
    What is that tool in relation to the rest of your workshop though? If it's a simple hammer that you can swap out for $20 and you only use it once a month, who cares what kind of metal it's made out of, as long as it works. But if the $6,000 4-axis CNC machine that's at the heart of your machine shop and every minute of downtime on it costs you money, if it's starting to rust, no, you don't have better things to do than to look into what it's made of.
kikimora 5mo ago
Nobody reviewed resulting code. Maybe all tests are empty and this is why they pass. Maybe tests were modified to pass because this is the only thing LLM could do to make them pass. Maybe it hallucinated something in the process. We have no idea.
- jsnell 5mo ago
  We do have an idea, and it contradicts your guess: https://news.ycombinator.com/item?id=48133806 https://news.ycombinator.com/item?id=48133806
  - kikimora 5mo ago
    You suggest there is only JS tests that do not need a rewrite? This is crazier than I thought… I took tests as an example. There are so many other things that can go wrong. Rust and Zig standard libraries may have different semantics not picked up by AI. Like one guarantees insertion order of a dictionary and other does not. Differences in how runtimes react to Linux signals, how they do file IO, etc. If I were a Bun user I would be moving off from bun unless it has excellent test coverage (which I think it does not). During a normal release cycle I offered a small increment of functionality with small number of issues. Here I’ve been offered a complete rewrite, potentially having thousands of issues. I don’t want to be a guinea pig in this experiment. I’m genuine curious how this will unfold.

by brabel 5mo ago

soraminazuki 5mo ago

Very amazing indeed. Here you are making bold assumptions about a huge pile of code not a single human being has ever read in any meaningful amount.

brabel 5mo ago
The only assumption you need to make is how the process went about, which was described by Jarred on a HN comment when the PR was first discussed: they had prompt that described exactly how things should be translated, for each "pattern" they were using in Zig, an appropriate equivalent was described in Rust. Zig and Rust are not that different, both are system languages and things can be done similarly in both languages, so architecture-wise I would think the exact same thing would work fine. I am not sure whether the LLM actually wrote a transpiler which just followed the rules, or if it did the job itself, since that information is not public yet, as far as I know, but my guess is that the LLM wrote a transpiler to do the job, then reviewed/fixed compilation issues, then fixed tests. And I'm pretty sure some human interaction was part of that as well.
- soraminazuki 5mo ago
  So now you've gone from making assumptions to making up wild stories territory. Well, the commit granularity isn't that of transpiler passes, and more importantly, it's completely irrelevant to how the majority of the code hasn't even been read by anyone.
- kikimora 5mo ago
  >The only assumption you need to make is how the process went about, which was described by Jarred This is not how the process went. This is how Jarred thinks it went, a huge difference. >my guess is that the LLM wrote a transpiler to do the job My guess is different. I think one agent translated code, another compiled it, feeding errors back into translator to fix. Then last agent modifies code to fix tests. All governed by a set of md files.

thayne 5mo ago

Zig and Rust are significantly different languages. If bun has a good architecture in zig (which I don't know if it does or not), that doesn't necessarily mean it had a good architecture for rust. A direct translation of zig code would probably result in pretty unusual rust code, and probably a lot more unsafe usage than if it had been originally written in rust.

adampunk 5mo ago
I don’t really understand this objection. For every tool that I use, am I supposed to divine the best underlying language for it and then determine whether or not it is written in that language? Don’t I have better things to do?
- kikimora 5mo ago
  Because of borrow checker you would build data structures differently in Rust compared to Zig. Automated translation simply maps Zig constructs onto unsafe Rust code. I have no idea how feasible it is to go from totally unique way of using Rust to mimic Zig to idiomatic Rust.
  - adampunk 5mo ago
    I understand that. That’s a specific example of an inaptness moving from one language to another. That’s not what I’m talking about. I am asking if we are expected to understand this hypothetical condition about all possible tools that we use. Should I have to worry that something is written in Python when it should’ve been written in C? It just seems like that in order to have a big concern here, I had to be really invested in what language Bun used. I guess the whole matter makes more sense if people are REALLY mad about something else and the choice of language is supposed to serve as a more respectable thing to be mad about.
- fragmede 5mo ago
  What is that tool in relation to the rest of your workshop though? If it's a simple hammer that you can swap out for $20 and you only use it once a month, who cares what kind of metal it's made out of, as long as it works. But if the $6,000 4-axis CNC machine that's at the heart of your machine shop and every minute of downtime on it costs you money, if it's starting to rust, no, you don't have better things to do than to look into what it's made of.

kikimora 5mo ago

Nobody reviewed resulting code. Maybe all tests are empty and this is why they pass. Maybe tests were modified to pass because this is the only thing LLM could do to make them pass. Maybe it hallucinated something in the process. We have no idea.

jsnell 5mo ago
We do have an idea, and it contradicts your guess: https://news.ycombinator.com/item?id=48133806 https://news.ycombinator.com/item?id=48133806
- kikimora 5mo ago
  You suggest there is only JS tests that do not need a rewrite? This is crazier than I thought… I took tests as an example. There are so many other things that can go wrong. Rust and Zig standard libraries may have different semantics not picked up by AI. Like one guarantees insertion order of a dictionary and other does not. Differences in how runtimes react to Linux signals, how they do file IO, etc. If I were a Bun user I would be moving off from bun unless it has excellent test coverage (which I think it does not). During a normal release cycle I offered a small increment of functionality with small number of issues. Here I’ve been offered a complete rewrite, potentially having thousands of issues. I don’t want to be a guinea pig in this experiment. I’m genuine curious how this will unfold.