How to Use Async Streams Effectively in Rust

Use async functions with await to pause execution until I/O completes, then chain calls to reduce boilerplate.

use scraper::{Html, Selector};
use reqwest;

async fn page_title(url: &str) -> Option<String> {
    let response_text = reqwest::get(url).await.ok()?.text().await.ok()?;
    Html::parse_document(&response_text)
        .select(&Selector::parse("title").ok()?)
        .next()
        .map(|title| title.text().collect::<String>())
}

This pattern allows your program to handle multiple network requests concurrently without blocking the main thread.

Async streams let your program start a task, like downloading a file, and then do other work while waiting for it to finish. Instead of freezing the whole app, it pauses just that specific task and picks it up again when the data arrives. Think of it like ordering coffee: you place the order and wait at the counter for other things, rather than standing in the kitchen watching the machine brew.