feature: builder pattern for application about bluer HOT 3 OPEN

This would be a good extension to the API.

It would also make sense to provide a wrapper function around CharacteristicWriteMethod::Fun and similar types that perform the boxing of the specified closure, i.e. Box::new(move |...| { async move { ... }.boxed() }).

I'd start out with the inner ones (e.g.: Characteristic::builder) and progressively add the higher one.

Yes, we can then discuss the proposed builder pattern in more detail.

from bluer.

It would also make sense to provide a wrapper function around CharacteristicWriteMethod::Fun and similar types that perform the boxing of the specified closure, i.e. Box::new(move |...| { async move { ... }.boxed() }).

Yeah, that's also kind ugly and repetitive. Ideally, the following:

CharacteristicWriteMethod::Fun(Box::new(move |new_value, req| {
    async move {
        todo!("{:?} {:?}", new_value, req);
    }
    .boxed()
})),

Could be written as:

CharacteristicWriteMethod::from(async move {
    todo!("{:?} {:?}", new_value, req);
}),

However, async closures are unstable: rust-lang/rust#62290.

I used bluer/examples/gatt_server_cb.rs for some experimenting around simplifying this bit anyway. I ended up hitting lifetime issues that come up due to the async block moving variables into its scope.

I'm not sure that there's anything actionable on simplifying CharacteristicWriteMethod definition.

from bluer.

You don't need async closures for that. You can create a wrapper function like this:

use futures::future::FutureExt;
use std::future::Future;
use std::io::Result;
use std::pin::Pin; // 0.3.30

pub type CharacteristicWriteFun =
    Box<dyn Fn(Vec<u8>, String) -> Pin<Box<dyn Future<Output = Result<()>> + Send>> + Send + Sync>;

pub enum CharacteristicWriteMethod {
    Fun(CharacteristicWriteFun),
    Io,
}

impl CharacteristicWriteMethod {
    pub fn fun<Fut>(f: impl Fn(Vec<u8>, String) -> Fut + Send + Sync + 'static) -> Self
    where
        Fut: Future<Output = Result<()>> + Send + 'static,
    {
        Self::Fun(Box::new(move |a, b| f(a, b).boxed()))
    }
}

fn main() {
    CharacteristicWriteMethod::fun(|a, b| async move { Ok(()) });
}

See https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=e1d0f1b90e94971cade64cc536713070

from bluer.