关于异步编程的思考

// 回调地狱
getData(function(a) {
    getMoreData(a, function(b) {
        getEvenMoreData(b, function(c) {
            console.log(c);
        });
    });
});

// async/await
async function main() {
    const a = await getData();
    const b = await getMoreData(a);
    const c = await getEvenMoreData(b);
    console.log(c);
}

use tokio::time::sleep;

#[tokio::main]
async fn main() {
    let handle = tokio::spawn(async {
        sleep(std::time::Duration::from_secs(1)).await;
        println!("background task done");
    });

    println!("waiting...");
    handle.await.unwrap();
}