embedded_io_adapters::unblock::Unblock: adapter from embedded_io::{Read, Write} to embedded_io_async::{Read, Write}

[alsuren]

Funny story: I burned a bunch of time writing this because I couldn't get embassy's examples/std/src/bin/serial.rs working. I assumed that there was some problem with their serial port adapter or something because it was never returning any data. It turns out my USB UART adapter has a developed broken RX, so this was a bit pointless 😢. I thought I'd share it anyway.

I'm not sure how useful it will be to people:

• It doesn't currently implement Seek.
• it's kind-of inefficient.
• the ergonomics are a bit naff, because it can't just assume embedded_io::ErrorType::Error = std::io::Error (there might be a way around this: I haven't thought about it too hard)

If anything, its main usefulness would probably be to point people towards async_io::Async, and give people a good chuckle at my expense. Feel free to close this PR if you don't think that it is useful. I'm also happy to re-work it, if you think it could be useful but just has the wrong shape.

[alsuren]

Turns out this can also be done with blocking::Unblock::new(). I can't get any of these approaches to read from stdin when porting my embassy project to work on desktop though. Probably best to close this until I have something that actually works.

[dess83-maker]

when

[alsuren]

@dess83-maker when is not a useful comment. Assuming that you are not a spam bot, please expand on your comment. [Edit: it's definitely a spam bot. I have blocked it. If enough people do, maybe GitHub will suspend the account for us?]

For anyone who came here tryng to turn a blocking stdin reader into an async reader in a std+embassy environment:

I think that a cleaner approach is to just write a blocking parser and then spawn a thread to dump the messages on a channel. See this code as an example:

https://github.com/hoverkite/hoverkite/pull/245/files#diff-2009529c3fa33e0843368f5f842d3ca1845ba36c7aedcd6751d3fe7121742730R124

It means that you end up with an awkward mix of blocking and async parsers dotted around your codebase, but I think it's fine.