Async Patterns

Patterns สำหรับ async/await programming

Async Function Basics

// async fn returns impl Future
async fn fetch_data() -> String {
    // Simulated async work
    "data from server".to_string()
}

async fn process_data(data: String) -> usize {
    data.len()
}

async fn main_workflow() -> usize {
    // .await suspends until complete
    let data = fetch_data().await;
    let result = process_data(data).await;
    result
}

fn main() {
    // Block on async in sync context
    // In real code, use tokio::main or async-std::main

    println!("Async patterns demonstration");

    // Futures are lazy - nothing runs until polled
    let future = fetch_data();  // Not executed yet
    println!("Future created");

    // Would need runtime to execute:
    // let result = tokio::runtime::Runtime::new()
    //     .unwrap()
    //     .block_on(main_workflow());
}