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0 pointsdminik8mo ago0 comments

Well, it's not really a joke. That's a valid strategy that languages use. In Go, every function is "async". And it basically blocks you from doing FFI (or at least it used to?). I wonder if Zig will run into similar issues here.

> 1. Code can't be reused because the async keyword statically colors a function

This is fair. And it's also a real pain point with Rust. However, it's funny that the "What color is your function?" article doesn't even really mention this.

> 2. Using async and await opts you automatically into stackless coroutines with no way of preventing that

This however I don't think is true. Async/await is mostly syntax sugar.

In Rust and C# it uses stackless coroutines.

In JS it uses callbacks.

There's nothing preventing you from making await suspend a green thread.

0 comments

kristoff_it8mo ago

I should have specified that better, of course async and await can be lowered to different things (that's what Zig does afterall), what I wanted to say is that that's how it works in general. JS is a good counter example, but for all other mainstream languages, async means stackless coroutines (python, ruby, c#, rust, ...).

Which means that if I want to use a dependency that uses async await, it's stackless coroutines for me too whether I like it or not.

sczi8mo ago

In ruby async is based on stackful fibers. With https://github.com/socketry/async-debug you can see a tree of all fibers with their full call stack. It also avoids the problem people talk about in this thread with go of passing a context parameter everywhere for cancellation as you can kill or raise any exception inside another fiber. I haven't used them but PHP fibers are also supposedly stackful. And Java and every JVM language has them since project loom in JDK 21.

kristoff_it8mo ago

My mistake, I should have said Python then.

thayne8mo ago

> And it basically blocks you from doing FFI

It doesn't block it. But it does make FFI much more expensive in go than in languages like Rust, because every foreign call needs to set up a c-compatible stack.

j / k navigate · click thread line to collapse

0 pointsdminik8mo ago0 comments

> 1. Code can't be reused because the async keyword statically colors a function

This is fair. And it's also a real pain point with Rust. However, it's funny that the "What color is your function?" article doesn't even really mention this.

> 2. Using async and await opts you automatically into stackless coroutines with no way of preventing that

This however I don't think is true. Async/await is mostly syntax sugar.

In Rust and C# it uses stackless coroutines.

In JS it uses callbacks.

There's nothing preventing you from making await suspend a green thread.

0 comments

kristoff_it8mo ago

Which means that if I want to use a dependency that uses async await, it's stackless coroutines for me too whether I like it or not.

sczi8mo ago

kristoff_it8mo ago

My mistake, I should have said Python then.

thayne8mo ago

> And it basically blocks you from doing FFI

It doesn't block it. But it does make FFI much more expensive in go than in languages like Rust, because every foreign call needs to set up a c-compatible stack.

j / k navigate · click thread line to collapse