[simjnd]

Thank you. I was left confused after people praised the Bun to Rust blog post eventhough it contained very actual technical substance. No clear evaluation of options, very biased report on impact, missing figures. It absolutely didn't feel like an engineering blog post.

Maybe people were more interested in the agentic part more than the actual rationale for the port in the first place, because it was very disappointing from a technical standpoint.

[cognitiveinline]

>very actual technical substance

Did we read the same article? I mean it wasn't talking about a specific line of code, but it had deep architecture details, rational for memory safety and bugs, agentic coding patterns for scale. It was full of substance, multiple times.

[simjnd]

I could point to the same examples this article refers to: the Bun blog post says "Having a rigid style guide [in Zig] with clear ownership expectations explicitly spelled out in the type system was a real option for Bun" and presents no technical reason why they didn't choose (or even TRY) that. They handwave it with "This is and ergonomic than the Zig we expect".

Why was it in their own words a real option? And why did they not go for it? This is the technical substance I'm looking for: an engineer explaining what options have been considered and what wanted and unwanted tradeoffs they present.

Also only mentioning figures for the platforms that saw an improvement is sketchy. "With ICU and code folding Windows and Linux get 20% smaller", what about macOS? Why did it not see the same gains? The fact that they don't mention it makes me think that they don't KNOW, and isn't confidence inspiring coming from the engineer who SHOULD know.

[lolinder]

The very next sentence justifies why they didn't do it: it argues that they would have ended up with what was technically Zig but something that was much less ergonomic than what would be expected from Zig.

You can argue that that's a bad justification for not doing it, but that's a debate on the technical merits, not a claim that they didn't provide justification.

[simjnd]

Yeah since my whole point is about the technical merits of the rewrite article, I don't count that as justification.

Why is just a wrapper type "less ergonomic"? Everybody does that all the time in every language. And then if you can convince me it is less "ergonomic": why does it matter if it solves the problem? And that is considering humans write the code manually. Why does it matter if agents write the code? This makes no sense.

[lolinder]

The example shows three extra lines of code, two of which are `defer`s. I'm not an expert in Zig and can't tell you whether the example they give is contrived, but the claim they're making is way more than "a wrapper type".

> And that is considering humans write the code manually. Why does it matter if agents write the code? This makes no sense.

Because the particular form of non-ergonomic code that is demonstrated here amounts to a quadrupling of tokens. That's a substantial hit to the context window for safety that isn't even statically enforced.

[simjnd]

A wrapper class if you want, a wrapper type with methods / dedicated functions. Still, seems pretty ergonomic to me. Yeah we went from one line to three, but the three lines guarantee safety whereas the one doesn't so?

Also I'm not sure the token count is very relevant for an Anthropic employee who just spent 165k worth of token rewriting the whole thing in Rust. Sprinkling a few defers here and there and swapping types surely would have been immensely cheaper in tokens.

[afavour]

As the article mentions, the follow on question from that is: why does that matter if your codebase is written exclusively by AI agents?

[lolinder]

Because if you have to quadruple the number of tokens in your code base in order to make the Zig provably safe, you have 1/4 of the context window to do useful work.

[afavour]

So why not say that? Perhaps because it highlights a flaw in AI agent workflows?

[cognitiveinline]

Every blog post has infinite things it does not mention.

"Technical substance" simply requires that some technically substantive things are mentioned. Which was indeed the case.

[simjnd]

Not about the things that matter.

If you write a blog post about "I switched from X to Y", I expect the WHY: the pros and cons of X, of Y, and of the alternatives that were considered and dismissed before considering Y.

This is more a blog post about how to use Fable to switch from X to Y, than it is about X or Y.