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.

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.

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”.

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).

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.

Keep (Neo)Vim out of this.

sublemmy

Lemmy communities. Mbin/kbin magazines.

Actually, I may have been too finicky about this myself.

Since I often write my own wrapping serialization code for use with non-serde formats, I didn’t realize that chrono::DateTime<chorono_tz::Tz> wasn’t serde-serializable, even with the serde feature enabled for both crates. That’s where the biggest problem probably lies.

In the example, using chorono_tz::Tz, and only converting to-be-serialized values to FixedOffset would probably put better focus on where the limitations/issues actually lie.

Like do you really not see this as something that shouldn’t be mentioned in a comparison between these crates? You must recognize the difference between what you’re doing and just plopping a Zoned in your struct, deriving Serialize and Deserialize, and then just letting the library do the right thing for you.

If that’s how it was framed in the comparison, it would have been fine. But my original objection was regarding the Local+FixedOffset example which, IMVHO, toys, if ever so slightly, with disingenuity (no offense or aggression intended, I’m a fan).

I think you also glossed over some of my other points. How do you write your serialization code using Chrono? Does it work with both chrono-tz and tzfile?

Something like this?

It can support tzfile too around the wire if it starts to expose tz names in a future version.

Why is the full presentation non-ephemerally stored instead of (timestamp, timezoe)?

Is the use-case strictly limited to checking the validity of a future date that was generated with assumptions based on current tzdata info? That’s valid, but quite niche I would argue.

And one can adjust the wrapper to have (timestamp, timezone, assumed_offset_at_ts). But yes, it can be argued that it’s not idiomatic/automatic/antecedently obvious anymore.

I think you misunderstood me.

What I meant is, someone who wants to serialize zoned dt info using chrono can basically send a timestamp and a timezone name on the wire, e.g. (1721599162, "America/New_York").

It’s not built-in support. It’s not a single human-readable string containing all the needed info that is being sent on the wire. But it does provide the needed info to get the correct results on the other side. And it’s the obvious solution to do, and it’s doable with trivial wrappers. No Local+FixedOffset usage required. And no wrong results inevitable.

That’s fine. I didn’t look at the code, but from what I gather, Jiff serializes the timezone name (not detailed tz info). chrono users would communicate the same thing, but it’s not built-in functionality in the dt type itself.

The example I referred to however may imply that chrono users would be inclined do the wrong thing, and get the wrong result as a sequence.

(humble personal opinion bit) It feels like it’s a case where the example was pushed a bit extra to fit into the “jump into the pit of success/despair” reference. A reference many, young and old, wouldn’t recognize, or otherwise wouldn’t care for anyway.

Yesterday I was browsing /r/programming

:tabclose

From COMPARE.md:

Conversely, in Jiff, all time zone lookups by name are cached.

Is the cache invalidated if system tzdata is updated?

And what effect does the answer have on the example from “Jiff supports detecting time zone offset conflicts” if both zoned datetimes used the system timezone which got updated between 1. opening 2. parsing the two zoned datetimes.

Jiff losslessly roundtrips time zone aware datetimes

In this section, wouldn’t be more realistic for chrono users to use timezone info around the wire instead of on the wire, rather than using Local+FixedOffset?