How to terminate a worker that is in communication with subscription::channel

[wangxiaochuTHU]

Hello, firstly I'd like to thank for your working on this performant Rust UI library.

Currently I'm considering a simple app to show data from backend. Following the instruction of some_worker() in subscription::channel, I think I've managed to make such a tuple of (tx, rx) work.

But my question is how to terminate the worker and quit its inner async loop?

I tried to use a kill signal to break the inner async loop, but the compiler complains about the return type. How to fix it?

expected `[async block@src\serial.rs:746:22: 778:10]` to be a future that resolves to `Infallible`, but it resolves to `()`
expected `Infallible`, found `()`

code

pub fn some_worker() -> Subscription<Message> {
    subscription::channel(
        std::any::TypeId::of::<usize>(),
        100,
        |mut output| async move {
            let mut state = State::Starting;
            loop {
                match &mut state {
                    State::Starting => {
                        // Create channel
                        let (sender, receiver) = mpsc::channel(100);

                        // Send the sender back to the application
                        output.send(Event::Starting(sender)).await;

                        // We are ready to receive messages
                        state = State::Ready(receiver);
                    }
                    State::Ready(receiver) => {
                        use iced_native::futures::StreamExt;

                        // Read next input sent from `Application`
                        let input = receiver.select_next_some().await;

                        output
                            .send(Event::Data(input))
                            .await;
                        // `input >= 10` means a kill signal
                        if input >= 10 {
                            state = State::Stopping;
                        }
                    }
                    State::Stopping => {
                        break;
                    }
                }
            }
        },
    )
}