joshka 3 hours ago

The weird-looking Rust isn’t really Rust being weird, it’s the type telling the truth.

   Result<Option<Result<Message, WsError>>, Elapsed>

That’s three independent “not the happy path” channels: timeout, stream closed, and websocket error.

The nicer version is not a cleverer match. It’s choosing a domain error shape and converting into it one layer at a time:

    let timed = tokio::time::timeout(duration, receiver.next()).await;
    let next = timed.map_err(|_| ReceiveError::Timeout)?;
    let item = next.ok_or(ReceiveError::Closed)?;
    let msg = item.map_err(ReceiveError::WebSocket)?; 

The ugly line is what happens when you have not decided where to normalize the shape yet.

  • loeg 3 hours ago
      Result<(), ()>
    

    Is pretty weird, though, no? Why would you want a unit value / error type?

    • tux3 2 hours ago

      Sometimes you just want a fancy boolean. The advantage is that Result has all the Result APIs and you can compose it with other Results, but otherwise this is just a success bool.

    • MrJohz 2 hours ago

      It's basically doing the same thing that, say, `return true` might do to indicate a function succeeded, but with more explicit types. However, because it uses `Result`, it can be used with the `try`/question mark operator which can be convenient in some situations.

      That said, a couple of the examples here feel a bit strange - they're clever things you can do, but they're not necessarily things you often have to do, particularly for a relatively simple task like this. I think the problem with the author's approach is that they can't distinguish between "weird because Rust is weird" and "weird because the LLM generated bad code", because they (understandably) don't have enough experience in what good Rust code looks like.

    • stingraycharles 2 hours ago

      It’s the equivalent of Haskell’s Either, with Option being the equivalent of Maybe. They’re fairly well-defined idioms.

      • loeg 2 hours ago

        I know what Result<> is.

    • nasso_dev 45 minutes ago

      it is indeed pretty weird. clippy has a lint against this iirc. it's recommended to just create a custom error type, even if its just an empty struct or a single-variant enum

      this lets you implement `std::error::Error`, which you really should to make it less painful when you want to erase the type (`std::error::Error` is `dyn`-compatible)

  • simianwords 37 minutes ago

    Off topic but using “shape” like this is LLM coded

    • bobnamob 33 minutes ago

      I guess I'm an LLM then. I've been referring to the structure of types as "shape" for more than a decade and so have plenty of others

    • joshka 13 minutes ago

      Probably on topic here - I talk like an LLM sometimes, and parse my points through them sometimes. I’d reasonably use that terminology and think nothing of it as it’s precise and correct. That said, this was partially LLM and my thinking here.

saagarjha 2 hours ago

I feel like having an LLM write code in a language you aren't familiar with and then inspecting the results is kind of like hiring someone to speak Spanish for you and then being confused at the weird words they are using. Like, what would make you want to do this?

  • victorbjorklund 1 hour ago

    If you already speak French or another Romance language it isn’t a bad idea to just have a conversation in Spanish directly and then ask for clarifications anytime you don’t understand.

    • 2ndorderthought 1 hour ago

      Which would be all the time? At which point you might be better served by learning from a source that has any guarantees of being correct and doesn't hallucinate. Like text books that have had several editions and are free on the Internet.

RobotToaster 3 hours ago

Was anyone else expecting OpenClaw over gopher protocol?

  • coqadoodle 2 hours ago

    I was looking forward to retro deep-dive back into the 90s. I just couldn't figure out where the crab fit in.

nothinkjustai 2 hours ago

Um? Person vibe codes Rust. Output is stupid. The conclusion is either

a) Vibe coding produces bad code

b) Rust is weird

Somehow we’re supposed to accept b as the answer? Give me a break….

  • 2ndorderthought 1 hour ago

    People really are forgetting how to think. While reading this blog post I almost immediately flipped into teaching confused freshmen taking the course that wasn't their major mode.