| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/async-stream-0.3.5/src/lib.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>lib.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../async_stream/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../async_stream/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="attribute">#![warn( |
| missing_debug_implementations, |
| missing_docs, |
| rust_2018_idioms, |
| unreachable_pub |
| )] |
| #![doc(test(no_crate_inject, attr(deny(rust_2018_idioms))))] |
| |
| </span><span class="doccomment">//! Asynchronous stream of elements. |
| //! |
| //! Provides two macros, `stream!` and `try_stream!`, allowing the caller to |
| //! define asynchronous streams of elements. These are implemented using `async` |
| //! & `await` notation. This crate works without unstable features. |
| //! |
| //! The `stream!` macro returns an anonymous type implementing the [`Stream`] |
| //! trait. The `Item` associated type is the type of the values yielded from the |
| //! stream. The `try_stream!` also returns an anonymous type implementing the |
| //! [`Stream`] trait, but the `Item` associated type is `Result<T, Error>`. The |
| //! `try_stream!` macro supports using `?` notation as part of the |
| //! implementation. |
| //! |
| //! # Usage |
| //! |
| //! A basic stream yielding numbers. Values are yielded using the `yield` |
| //! keyword. The stream block must return `()`. |
| //! |
| //! ```rust |
| //! use async_stream::stream; |
| //! |
| //! use futures_util::pin_mut; |
| //! use futures_util::stream::StreamExt; |
| //! |
| //! #[tokio::main] |
| //! async fn main() { |
| //! let s = stream! { |
| //! for i in 0..3 { |
| //! yield i; |
| //! } |
| //! }; |
| //! |
| //! pin_mut!(s); // needed for iteration |
| //! |
| //! while let Some(value) = s.next().await { |
| //! println!("got {}", value); |
| //! } |
| //! } |
| //! ``` |
| //! |
| //! Streams may be returned by using `impl Stream<Item = T>`: |
| //! |
| //! ```rust |
| //! use async_stream::stream; |
| //! |
| //! use futures_core::stream::Stream; |
| //! use futures_util::pin_mut; |
| //! use futures_util::stream::StreamExt; |
| //! |
| //! fn zero_to_three() -> impl Stream<Item = u32> { |
| //! stream! { |
| //! for i in 0..3 { |
| //! yield i; |
| //! } |
| //! } |
| //! } |
| //! |
| //! #[tokio::main] |
| //! async fn main() { |
| //! let s = zero_to_three(); |
| //! pin_mut!(s); // needed for iteration |
| //! |
| //! while let Some(value) = s.next().await { |
| //! println!("got {}", value); |
| //! } |
| //! } |
| //! ``` |
| //! |
| //! Streams may be implemented in terms of other streams - `async-stream` provides `for await` |
| //! syntax to assist with this: |
| //! |
| //! ```rust |
| //! use async_stream::stream; |
| //! |
| //! use futures_core::stream::Stream; |
| //! use futures_util::pin_mut; |
| //! use futures_util::stream::StreamExt; |
| //! |
| //! fn zero_to_three() -> impl Stream<Item = u32> { |
| //! stream! { |
| //! for i in 0..3 { |
| //! yield i; |
| //! } |
| //! } |
| //! } |
| //! |
| //! fn double<S: Stream<Item = u32>>(input: S) |
| //! -> impl Stream<Item = u32> |
| //! { |
| //! stream! { |
| //! for await value in input { |
| //! yield value * 2; |
| //! } |
| //! } |
| //! } |
| //! |
| //! #[tokio::main] |
| //! async fn main() { |
| //! let s = double(zero_to_three()); |
| //! pin_mut!(s); // needed for iteration |
| //! |
| //! while let Some(value) = s.next().await { |
| //! println!("got {}", value); |
| //! } |
| //! } |
| //! ``` |
| //! |
| //! Rust try notation (`?`) can be used with the `try_stream!` macro. The `Item` |
| //! of the returned stream is `Result` with `Ok` being the value yielded and |
| //! `Err` the error type returned by `?`. |
| //! |
| //! ```rust |
| //! use tokio::net::{TcpListener, TcpStream}; |
| //! |
| //! use async_stream::try_stream; |
| //! use futures_core::stream::Stream; |
| //! |
| //! use std::io; |
| //! use std::net::SocketAddr; |
| //! |
| //! fn bind_and_accept(addr: SocketAddr) |
| //! -> impl Stream<Item = io::Result<TcpStream>> |
| //! { |
| //! try_stream! { |
| //! let mut listener = TcpListener::bind(addr).await?; |
| //! |
| //! loop { |
| //! let (stream, addr) = listener.accept().await?; |
| //! println!("received on {:?}", addr); |
| //! yield stream; |
| //! } |
| //! } |
| //! } |
| //! ``` |
| //! |
| //! # Implementation |
| //! |
| //! The `stream!` and `try_stream!` macros are implemented using proc macros. |
| //! The macro searches the syntax tree for instances of `yield $expr` and |
| //! transforms them into `sender.send($expr).await`. |
| //! |
| //! The stream uses a lightweight sender to send values from the stream |
| //! implementation to the caller. When entering the stream, an `Option<T>` is |
| //! stored on the stack. A pointer to the cell is stored in a thread local and |
| //! `poll` is called on the async block. When `poll` returns. |
| //! `sender.send(value)` stores the value that cell and yields back to the |
| //! caller. |
| //! |
| //! [`Stream`]: https://docs.rs/futures-core/*/futures_core/stream/trait.Stream.html |
| |
| </span><span class="kw">mod </span>async_stream; |
| <span class="kw">mod </span>next; |
| <span class="kw">mod </span>yielder; |
| |
| <span class="doccomment">/// Asynchronous stream |
| /// |
| /// See [crate](index.html) documentation for more details. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use async_stream::stream; |
| /// |
| /// use futures_util::pin_mut; |
| /// use futures_util::stream::StreamExt; |
| /// |
| /// #[tokio::main] |
| /// async fn main() { |
| /// let s = stream! { |
| /// for i in 0..3 { |
| /// yield i; |
| /// } |
| /// }; |
| /// |
| /// pin_mut!(s); // needed for iteration |
| /// |
| /// while let Some(value) = s.next().await { |
| /// println!("got {}", value); |
| /// } |
| /// } |
| /// ``` |
| </span><span class="attribute">#[macro_export] |
| </span><span class="macro">macro_rules! </span>stream { |
| ($(<span class="macro-nonterminal">$tt</span>:tt)<span class="kw-2">*</span>) => { |
| <span class="macro-nonterminal">$</span><span class="macro">crate::__private::stream_inner!</span>((<span class="macro-nonterminal">$</span><span class="kw">crate</span>) $(<span class="macro-nonterminal">$tt</span>)<span class="kw-2">*</span>) |
| } |
| } |
| |
| <span class="doccomment">/// Asynchronous fallible stream |
| /// |
| /// See [crate](index.html) documentation for more details. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use tokio::net::{TcpListener, TcpStream}; |
| /// |
| /// use async_stream::try_stream; |
| /// use futures_core::stream::Stream; |
| /// |
| /// use std::io; |
| /// use std::net::SocketAddr; |
| /// |
| /// fn bind_and_accept(addr: SocketAddr) |
| /// -> impl Stream<Item = io::Result<TcpStream>> |
| /// { |
| /// try_stream! { |
| /// let mut listener = TcpListener::bind(addr).await?; |
| /// |
| /// loop { |
| /// let (stream, addr) = listener.accept().await?; |
| /// println!("received on {:?}", addr); |
| /// yield stream; |
| /// } |
| /// } |
| /// } |
| /// ``` |
| </span><span class="attribute">#[macro_export] |
| </span><span class="macro">macro_rules! </span>try_stream { |
| ($(<span class="macro-nonterminal">$tt</span>:tt)<span class="kw-2">*</span>) => { |
| <span class="macro-nonterminal">$</span><span class="macro">crate::__private::try_stream_inner!</span>((<span class="macro-nonterminal">$</span><span class="kw">crate</span>) $(<span class="macro-nonterminal">$tt</span>)<span class="kw-2">*</span>) |
| } |
| } |
| |
| <span class="comment">// Not public API. |
| </span><span class="attribute">#[doc(hidden)] |
| </span><span class="kw">pub mod </span>__private { |
| <span class="kw">pub use </span><span class="kw">crate</span>::async_stream::AsyncStream; |
| <span class="kw">pub use </span><span class="kw">crate</span>::next::next; |
| <span class="kw">pub use </span>async_stream_impl::{stream_inner, try_stream_inner}; |
| <span class="kw">pub mod </span>yielder { |
| <span class="kw">pub use </span><span class="kw">crate</span>::yielder::pair; |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="async_stream" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
