| <!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="github crates-io docs-rs"><meta name="keywords" content="rust, rustlang, rust-lang, quote"><title>quote - Rust</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="../crates.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 mod crate"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../quote/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../quote/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Crate quote</a></h2><div class="sidebar-elems"><ul class="block"><li class="version">Version 1.0.28</li><li><a id="all-types" href="all.html">All Items</a></li></ul><section><ul class="block"><li><a href="#macros">Macros</a></li><li><a href="#traits">Traits</a></li></ul></section></div></nav><main><div class="width-limiter"><nav class="sub"><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="main-heading"><h1 class="fqn">Crate <a class="mod" href="#">quote</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../src/quote/lib.rs.html#1-1442">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p><a href="https://github.com/dtolnay/quote"><img src="https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github" alt="github" /></a> <a href="https://crates.io/crates/quote"><img src="https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust" alt="crates-io" /></a> <a href="https://docs.rs/quote"><img src="https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs" alt="docs-rs" /></a></p> |
| <br> |
| <p>This crate provides the <a href="macro.quote.html"><code>quote!</code></a> macro for turning Rust syntax tree data |
| structures into tokens of source code.</p> |
| <p>Procedural macros in Rust receive a stream of tokens as input, execute |
| arbitrary Rust code to determine how to manipulate those tokens, and produce |
| a stream of tokens to hand back to the compiler to compile into the caller’s |
| crate. Quasi-quoting is a solution to one piece of that — producing |
| tokens to return to the compiler.</p> |
| <p>The idea of quasi-quoting is that we write <em>code</em> that we treat as <em>data</em>. |
| Within the <code>quote!</code> macro, we can write what looks like code to our text |
| editor or IDE. We get all the benefits of the editor’s brace matching, |
| syntax highlighting, indentation, and maybe autocompletion. But rather than |
| compiling that as code into the current crate, we can treat it as data, pass |
| it around, mutate it, and eventually hand it back to the compiler as tokens |
| to compile into the macro caller’s crate.</p> |
| <p>This crate is motivated by the procedural macro use case, but is a |
| general-purpose Rust quasi-quoting library and is not specific to procedural |
| macros.</p> |
| <div class="example-wrap"><pre class="language-toml"><code>[dependencies] |
| quote = "1.0"</code></pre></div><br> |
| <h2 id="example"><a href="#example">Example</a></h2> |
| <p>The following quasi-quoted block of code is something you might find in <a href="https://serde.rs/">a</a> |
| procedural macro having to do with data structure serialization. The <code>#var</code> |
| syntax performs interpolation of runtime variables into the quoted tokens. |
| Check out the documentation of the <a href="macro.quote.html"><code>quote!</code></a> macro for more detail about |
| the syntax. See also the <a href="macro.quote_spanned.html"><code>quote_spanned!</code></a> macro which is important for |
| implementing hygienic procedural macros.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">let </span>tokens = <span class="macro">quote! </span>{ |
| <span class="kw">struct </span>SerializeWith #generics #where_clause { |
| value: <span class="kw-2">&</span><span class="lifetime">'a </span>#field_ty, |
| phantom: core::marker::PhantomData<#item_ty>, |
| } |
| |
| <span class="kw">impl </span>#generics serde::Serialize <span class="kw">for </span>SerializeWith #generics #where_clause { |
| <span class="kw">fn </span>serialize<S>(<span class="kw-2">&</span><span class="self">self</span>, serializer: S) -> <span class="prelude-ty">Result</span><S::Ok, S::Error> |
| <span class="kw">where |
| </span>S: serde::Serializer, |
| { |
| #path(<span class="self">self</span>.value, serializer) |
| } |
| } |
| |
| SerializeWith { |
| value: #value, |
| phantom: core::marker::PhantomData::<#item_ty>, |
| } |
| };</code></pre></div> |
| <br> |
| <h2 id="non-macro-code-generators"><a href="#non-macro-code-generators">Non-macro code generators</a></h2> |
| <p>When using <code>quote</code> in a build.rs or main.rs and writing the output out to a |
| file, consider having the code generator pass the tokens through |
| <a href="https://github.com/dtolnay/prettyplease">prettyplease</a> before writing. This way if an error occurs in the generated |
| code it is convenient for a human to read and debug.</p> |
| </div></details><h2 id="macros" class="small-section-header"><a href="#macros">Macros</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.format_ident.html" title="quote::format_ident macro">format_ident</a></div><div class="item-right docblock-short">Formatting macro for constructing <code>Ident</code>s.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.quote.html" title="quote::quote macro">quote</a></div><div class="item-right docblock-short">The whole point.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.quote_spanned.html" title="quote::quote_spanned macro">quote_spanned</a></div><div class="item-right docblock-short">Same as <code>quote!</code>, but applies a given span to all tokens originating within |
| the macro invocation.</div></div></div><h2 id="traits" class="small-section-header"><a href="#traits">Traits</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="trait" href="trait.IdentFragment.html" title="quote::IdentFragment trait">IdentFragment</a></div><div class="item-right docblock-short">Specialized formatting trait used by <code>format_ident!</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="trait" href="trait.ToTokens.html" title="quote::ToTokens trait">ToTokens</a></div><div class="item-right docblock-short">Types that can be interpolated inside a <code>quote!</code> invocation.</div></div><div class="item-row"><div class="item-left module-item"><a class="trait" href="trait.TokenStreamExt.html" title="quote::TokenStreamExt trait">TokenStreamExt</a></div><div class="item-right docblock-short">TokenStream extension trait with methods for appending tokens.</div></div></div></section></div></main><div id="rustdoc-vars" data-root-path="../" data-current-crate="quote" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
