embassy VS async-std

The other comment implied it but I think it's worth pointing out that:

> embedded applications that can't have asynchronous execution

Is most definitely not the case.

They can't have the same type of async runtime that would be optimal for a web server or the likes (and I'm not sure all desktop applications and web servers are going to always benefit from the same runtime in the same way), but that's a point in favour of Rust's model imho

If you're interested this is an embedded async runtime that's expected to run in no-std and no-alloc environments

https://embassy.dev/

In this article, I will guide you through creating a Snake game in embedded Rust on the BBC Micro:bit using the asynchronous framework Embassy.

Rust solved this by autogenning code from mfgr published device xml descriptors. Eg https://embassy.dev/

Better than any C(++) embedded hal I've used

If I get your question right, you still need some host software (like a rust compiler)! It's not exactly micropython experience.

The bare minimum would be one of the examples [1] compiled with a Rust compiler and then transformed into a .uf2 file with elf2uf2 [2]. You can then just drag and drop the .uf2 file into the "mass storage device" presented by the bootloader. To get the bootloader to mount, you press a button on a Raspberry Pico (or short two outputs if you're using bare RP2040) while plugging it in.

You'll probably want a debug probe [3] driven by probe-rs [4] at some point, it's just much more convenient to flash and debug with it.

[1]: https://github.com/embassy-rs/embassy/tree/main/examples/rp/...

[2]: https://github.com/JoNil/elf2uf2-rs

[3]: https://www.raspberrypi.com/documentation/microcontrollers/d...

[4]: https://probe.rs/

thanks. looked that up. for the curious: https://embassy.dev/

But maybe check out the discussion here https://github.com/async-rs/async-std/pull/631 or something (the blog post was linked on the end of it)

Have a look at these: https://github.com/async-rs/async-std/tree/main/examples

In fact, there are a lot of crates in Rust where in other programming languages, it would be included in the standard library. Examples are regex, random number generators, additional iterator methods, macros for other collections, num traits, loggers, HTTP libraries, error handling, async runtimes, serialization and deserialization, date and time, and many more.

Two major projects (non std lib but extremely commonly used) stand out in the area of async programming: Async std and Tokio - no doubt familiar to anyone that has turned an eye towards Rust for a second too long. Async architecture in general is likely very familiar to JavaScript programmers but in Rust there are some extra considerations (like ownership of the data that is thrown into an async function). Tokio is fast becoming a heavily supported and road tested async framework, with a thread scheduling runtime "baked in" that has learned from the history of Go, Erlang, and Java thread schedulers.

Ah... https://github.com/tokio-rs/tokio and https://github.com/async-rs/async-std ?

async-std: Basically a Tokio alternative with a few different design decisions.

Go's solution is for the scheduler to notice after a while when a goroutine has blocked execution and to shift goroutines waiting their turn to another thread. async-std pondered a similar approach with tasks, but it proved controversial and was never merged.

This indicates curl, zlib, openssl, and libnghttp2 as well as a bunch of WASM-related things are being dynamically linked into my executable. To resolve this, I looked at the build features exposed by surf and found that it selects the "curl_client" feature by default, which can be turned off and replaced with "h1-client-rustls" which uses an HTTP client backed by rustls and async-std and no dynamically linked libraries. Enabling this build feature removed all -sys dependencies from androidx-release-watcher, allowing me to build static executables of it.

And also, the actual PR never got merged.

Async in rust needs a runtime (aka executor) to run. You can maybe get a better description from the rust docs. As an example, Tokio attempts to provide an interface for a developer that is minimal change to the more common blocking code. So you'd end up putting #[tokio::main] above your main function to spin up the executor and most of the rest of the code is similar to a non-async version with a few sprinkles of .await, which you can see in the hello world for tokio. In contrast, async-std provides a more hands-on/low-level approach. If you are unlucky enough to have libraries that choose different stacks to work on, you'll possibly (probably?) have to handle both.