Async-Await

Deprecated in favour to the standard RFC that just has been approved:

https://github.com/rust-lang/rfcs/blob/master/text/2394-async_await.md

Just two macros to emulate a simple Async and Await using Futures (provided by futures-rs thanks to @cmgriffing for port it).

Usage

This is available in crates.io. Add this to your Cargo.toml:

[dependencies]
async-await = "0.2.1"

Example

Here is a simple example, you need to do the #[macro_use] and use async_await::*; because of the expansion of the macros :)

#[macro_use]
extern crate async_await;

use async_await::*;

fn main() {
    let computation = async!{"Hello world!"};
    println!("{}", await!(computation));
}

Another example using hyper, a shared client and a block in async :)

#[macro_use]
extern crate async_await;
extern crate hyper;

use std::io::Read;
use std::sync::Arc;

use async_await::*;

use hyper::Client;
use hyper::header::Connection;

fn main() {
    let client = Arc::new(Client::new());

    let client_comp = client.clone();
    let computation = async!{{
        let mut res = client_comp.get("http://rust-lang.org/")
            .header(Connection::close())
            .send().unwrap();
        let mut body = String::new();
        res.read_to_string(&mut body).unwrap();
        body
    }};

    println!("Before await!");
    println!("{}", await!{computation});
    println!("After await!");
}

You can also provide a default value in case that the computation fails:

#[macro_use]
extern crate async_await;

use async_await::*;

fn main() {
    let computation = async!{panic!(":()")};
    assert_eq!("Recovered!", await!{computation, "Recovered!"});
}

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.