…and that’s how you drive up metrics.

Gross!

Unprofessional.
This is why no one takes Rust seriously.

but futures only execute when polled.

The most interesting part here is the polling only has to take place on the scope itself. That was actually what I wanted to check, but got distracted because all spawns are awaited in the scope in moro’s README example.

async fn slp() {
    tokio::time::sleep(std::time::Duration::from_millis(1)).await
}

async fn _main() {
    let result_fut = moro::async_scope!(|scope| {
        dbg!("d1");
        scope.spawn(async { 
            dbg!("f1a");
            slp().await;
            slp().await;
            slp().await;
            dbg!("f1b");
        });
        dbg!("d2"); // 11
        scope.spawn(async {
            dbg!("f2a");
            slp().await;
            slp().await;
            dbg!("f2b");
        });
        dbg!("d3"); // 14
        scope.spawn(async {
            dbg!("f3a");
            slp().await;
            dbg!("f3b");
        });
        dbg!("d4");
        async { dbg!("b1"); } // never executes
    });
    slp().await;
    dbg!("o1");
    let _ = result_fut.await;
}

fn main() {
    let rt = tokio::runtime::Builder::new_multi_thread()
        .enable_all()
        .build()
        .unwrap();
    rt.block_on(_main())
}

[src/main.rs:32:5] "o1" = "o1"
[src/main.rs:7:9] "d1" = "d1"
[src/main.rs:15:9] "d2" = "d2"
[src/main.rs:22:9] "d3" = "d3"
[src/main.rs:28:9] "d4" = "d4"
[src/main.rs:9:13] "f1a" = "f1a"
[src/main.rs:17:13] "f2a" = "f2a"
[src/main.rs:24:13] "f3a" = "f3a"
[src/main.rs:26:13] "f3b" = "f3b"
[src/main.rs:20:13] "f2b" = "f2b"
[src/main.rs:13:13] "f1b" = "f1b"

The non-awaited jobs are run concurrently as the moro docs say. But what if we immediately await f2?

[src/main.rs:32:5] "o1" = "o1"
[src/main.rs:7:9] "d1" = "d1"
[src/main.rs:15:9] "d2" = "d2"
[src/main.rs:9:13] "f1a" = "f1a"
[src/main.rs:17:13] "f2a" = "f2a"
[src/main.rs:20:13] "f2b" = "f2b"
[src/main.rs:22:9] "d3" = "d3"
[src/main.rs:28:9] "d4" = "d4"
[src/main.rs:24:13] "f3a" = "f3a"
[src/main.rs:13:13] "f1b" = "f1b"
[src/main.rs:26:13] "f3b" = "f3b"

f1 and f2 are run concurrently, f3 is run after f2 finishes, but doesn’t have to wait for f1 to finish, which is maybe obvious, but… (see below).

So two things here:

1. Re-using the spawn terminology here irks me for some reason. I don’t know what would be better though. Would defer_to_scope() be confusing if the job is awaited in the scope?
2. Even if assumed obvious, a note about execution order when there is a mix of awaited and non-awaited jobs is worth adding to the documentation IMHO.

I skimmed the latter parts of this post since I felt like I read it all before, but I think moro is new to me. I was intrigued to find out how scoped span exactly behaves.

async fn slp() {
    tokio::time::sleep(std::time::Duration::from_millis(1)).await
}

async fn _main() {
    let value = 22;
    let result_fut = moro::async_scope!(|scope| {
        dbg!(); // line 8
        let future1 = scope.spawn(async {
            slp().await;
            dbg!(); // line 11
            let future2 = scope.spawn(async {
                slp().await;
                dbg!(); // line 14
                value // access stack values that outlive scope
            });
            slp().await;
            dbg!(); // line 18

            let v = future2.await * 2;
            v
        });

        slp().await;
        dbg!(); // line 25
        let v = future1.await * 2;
        slp().await;
        dbg!(); // line 28
        v
    });
    slp().await;
    dbg!(); // line 32
    let result = result_fut.await;
    eprintln!("{result}"); // prints 88
}

fn main() {
    // same output with `new_current_thread()` of course
    let rt = tokio::runtime::Builder::new_multi_thread()
        .enable_all()
        .build()
        .unwrap();
    rt.block_on(_main())
}

This prints:

[src/main.rs:32:5]
[src/main.rs:8:9]
[src/main.rs:25:9]
[src/main.rs:11:13]
[src/main.rs:18:13]
[src/main.rs:14:17]
[src/main.rs:28:9]
88

So scoped spawn doesn’t really spawn tasks as one might mistakenly think!

Because non-open ones are not available, even for a price. Unless you buy something bigger than the “standard” itself of course, like a company that is responsible for it or having access to it.

There is also the process of standardization itself, with committees, working groups, public proposals, …etc involved.

Anyway, we can’t backtrack on calling ISO standards and their likes “open” on the global level, hence my suggestion to use more precise language (“publicly available and sharable”) when talking about truly open standards.

The term open-standard does not cut it. People should start using “publicly available and sharable” instead (maybe there is a better name for it).

ISO standards for example are technically “open”. But how relevant is that to a curious individual developer when anything you need to implement would require access to multiple “open” standards, each coming with a (monetary) price, with some extra shenanigans ^[archived] on top.

IETF standards however are actually truly open, as in publicly available and sharable.

The LARPing levels in moronix comments are higher than usual, but the comedic value is still not lost.

Monthly Reminder: High or low, all Linux usage stats are fake.

I think your second link isn’t what you intended?

You scared me for a moment there. I don’t know why you thought that.

Needless to say, even with the first example, metavar expressions are not strictly needed here, as using a second pattern and recursing expansions would work.

But I wanted to showcase the power of ${ignore}, as it can be cleaner and/or more powerful in some cases where extra patterns and recursing expansions can get messy and hard to track.

Is this crazy?

A general repeat macro that works on stable Rust would work too of course.

@FizzyOrange@programming.dev

BTW, the snippet I pointed to, and the whole match block, is not incoherent. It’s useless.

First of all, unsafe famously doesn’t disable the borrow checker, which is something any Rustacean would know, so your intro is a bit weird in that regard.

And if you neither like the borrow checker, nor like unsafe rust as is, then why are you forcing yourself to use Rust at all. If you’re bored with C++, there are other of languages out there, a couple of which are even primarily developed by game developers, for game developers.

The fact that you found a pattern that can be alternatively titled “A Generic Method For Introducing Heisenbugs In Rust”, and you are somehow excited about it, indicates that you probably should stop this endeavor.

Generally speaking, I think the Rust community would benefit from making an announcement a long the lines of “If you’re a game developer, then we strongly advise you to become a Rustacean outside the field of game development first, before considering doing game development in Rust”.

Alright. Explain this snippet and what you think it achieves:

tokio::task::spawn_blocking(move || -> Result { Ok(walkdir) })

Post the original code to !rust@programming.dev and point to where you got stock, because that AI output is nonsensical to the point where I’m not sure what excited you about it. A self-contained example would be ideal, otherwise, include the crates you’re using (or the use statements).

Federation is irrelevant. Matrix is federated, yet most communities and users would lose communication if matrix.org got offline.

With, transport-only distributablity, which i think is what radicale offers, availability would depend on the peers. That means probably less availability than a big service host.

Distributed transport and storage would fix this. a la something like Tahoe-LAFS or (old) Freenet/Hyphanet. And no, IPFS is not an option because it’s generally a meme, and is pull-based, and have availability/longevity problems with metadata alone. iroh claims to be less of a meme, but I don’t know if they fixed any of the big design (or rather lack of design) problems.

At the end of the day, people can live with GitHub/GitLab/… going down for a few minutes every other week, or 1-2 hours every other month, as the benefits outweigh the occasional inconvenience by a big margin.

And git itself is distributed anyway. So it’s not like anyone was cut from committing work locally or pushing commits to a mirror.

I guess waiting on CI runs would be the most relevant inconvenience. But that’s not a distributable part of any service/implementation that exists, or can exist without being quickly gravely abused.

for a build of your crate only: single core perf.

Until the parallel compiler feature (-Z threads=<n>) stabilizes and becomes more complete.

It’s also always worth mentioning that the choice of linker is important. Using mold or lld can significantly speed things up in some use-cases.

Beyond that, codegen-units and lto profile options are also important.

And finally, for development purposes, the code generator is important, as cranelift provides much faster compile times, but resulting binaries are not as optimized as LLVM-generated ones.

Definitely don’t use axum, which provides a simple interface for routes by using derived traits. Their release cycle is way shorter, which makes them more dangerous, and they’re part of the same github user as tokio, which means they’re shilling their own product.

this but (semi)-unironucally

Your answer wanders a bit unnecessarily IMHO.

• no-std Rust has no run-time dependencies of its own.
• std Rust runtime-requirements are basically libc, a heap allocator, and a threading library. Many implementations on many OSes are already supported, including musl on Linux. And what’s not supported can theoretically be so in the future.
• Code generation at build-time is dependent on LLVM, with cranelift and (soon) GCC available as not fully mature alternatives.
• 3rd party code/crates may impose additional requirements.

Good.

Can you formulate your question better, with a minimal example and properly formatted code?

If you’re using an LLM to “learn”, stop. Otherwise, I don’t understand what lazy_static has to do with anything.

It’s hard to tell what you’re asking. But maybe you’re confused because println! (it’s a macro btw) expands to code that involves format_args! which is a compiler built-in that doesn’t take ownership of the token expressions that get passed to it. Notice how the bottom of the format_args! page has this to say:

Lifetime limitation

Except when no formatting arguments are used, the produced fmt::Arguments value borrows temporary values, which means it can only be used within the same expression and cannot be stored for later use. This is a known limitation, see #92698.

So, it’s kind of a feature and a limitation at the same time.