| <!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, syn"><title>syn - 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="../syn/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="../syn/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Crate syn</a></h2><div class="sidebar-elems"><ul class="block"><li class="version">Version 2.0.18</li><li><a id="all-types" href="all.html">All Items</a></li></ul><section><ul class="block"><li><a href="#modules">Modules</a></li><li><a href="#macros">Macros</a></li><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li><li><a href="#functions">Functions</a></li><li><a href="#types">Type Definitions</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="#">syn</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/syn/lib.rs.html#1-967">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/syn"><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/syn"><img src="https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust" alt="crates-io" /></a> <a href="index.html"><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>Syn is a parsing library for parsing a stream of Rust tokens into a syntax |
| tree of Rust source code.</p> |
| <p>Currently this library is geared toward use in Rust procedural macros, but |
| contains some APIs that may be useful more generally.</p> |
| <ul> |
| <li> |
| <p><strong>Data structures</strong> — Syn provides a complete syntax tree that can |
| represent any valid Rust source code. The syntax tree is rooted at |
| <a href="struct.File.html"><code>syn::File</code></a> which represents a full source file, but there are other |
| entry points that may be useful to procedural macros including |
| <a href="enum.Item.html"><code>syn::Item</code></a>, <a href="enum.Expr.html"><code>syn::Expr</code></a> and <a href="enum.Type.html"><code>syn::Type</code></a>.</p> |
| </li> |
| <li> |
| <p><strong>Derives</strong> — Of particular interest to derive macros is |
| <a href="struct.DeriveInput.html"><code>syn::DeriveInput</code></a> which is any of the three legal input items to a |
| derive macro. An example below shows using this type in a library that can |
| derive implementations of a user-defined trait.</p> |
| </li> |
| <li> |
| <p><strong>Parsing</strong> — Parsing in Syn is built around <a href="parse/index.html">parser functions</a> with the |
| signature <code>fn(ParseStream) -> Result<T></code>. Every syntax tree node defined |
| by Syn is individually parsable and may be used as a building block for |
| custom syntaxes, or you may dream up your own brand new syntax without |
| involving any of our syntax tree types.</p> |
| </li> |
| <li> |
| <p><strong>Location information</strong> — Every token parsed by Syn is associated with a |
| <code>Span</code> that tracks line and column information back to the source of that |
| token. These spans allow a procedural macro to display detailed error |
| messages pointing to all the right places in the user’s code. There is an |
| example of this below.</p> |
| </li> |
| <li> |
| <p><strong>Feature flags</strong> — Functionality is aggressively feature gated so your |
| procedural macros enable only what they need, and do not pay in compile |
| time for all the rest.</p> |
| </li> |
| </ul> |
| <br> |
| <h2 id="example-of-a-derive-macro"><a href="#example-of-a-derive-macro">Example of a derive macro</a></h2> |
| <p>The canonical derive macro using Syn looks like this. We write an ordinary |
| Rust function tagged with a <code>proc_macro_derive</code> attribute and the name of |
| the trait we are deriving. Any time that derive appears in the user’s code, |
| the Rust compiler passes their data structure as tokens into our macro. We |
| get to execute arbitrary Rust code to figure out what to do with those |
| tokens, then hand some tokens back to the compiler to compile into the |
| user’s crate.</p> |
| <div class="example-wrap"><pre class="language-toml"><code>[dependencies] |
| syn = "2.0" |
| quote = "1.0" |
| |
| [lib] |
| proc-macro = true</code></pre></div> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>proc_macro::TokenStream; |
| <span class="kw">use </span>quote::quote; |
| <span class="kw">use </span>syn::{parse_macro_input, DeriveInput}; |
| |
| <span class="attribute">#[proc_macro_derive(MyMacro)] |
| </span><span class="kw">pub fn </span>my_macro(input: TokenStream) -> TokenStream { |
| <span class="comment">// Parse the input tokens into a syntax tree |
| </span><span class="kw">let </span>input = <span class="macro">parse_macro_input!</span>(input <span class="kw">as </span>DeriveInput); |
| |
| <span class="comment">// Build the output, possibly using quasi-quotation |
| </span><span class="kw">let </span>expanded = <span class="macro">quote! </span>{ |
| <span class="comment">// ... |
| </span>}; |
| |
| <span class="comment">// Hand the output tokens back to the compiler |
| </span>TokenStream::from(expanded) |
| }</code></pre></div> |
| <p>The <a href="https://github.com/dtolnay/syn/tree/master/examples/heapsize"><code>heapsize</code></a> example directory shows a complete working implementation |
| of a derive macro. The example derives a <code>HeapSize</code> trait which computes an |
| estimate of the amount of heap memory owned by a value.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">pub trait </span>HeapSize { |
| <span class="doccomment">/// Total number of bytes of heap memory owned by `self`. |
| </span><span class="kw">fn </span>heap_size_of_children(<span class="kw-2">&</span><span class="self">self</span>) -> usize; |
| }</code></pre></div> |
| <p>The derive macro allows users to write <code>#[derive(HeapSize)]</code> on data |
| structures in their program.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="attribute">#[derive(HeapSize)] |
| </span><span class="kw">struct </span>Demo<<span class="lifetime">'a</span>, T: <span class="question-mark">?</span>Sized> { |
| a: Box<T>, |
| b: u8, |
| c: <span class="kw-2">&</span><span class="lifetime">'a </span>str, |
| d: String, |
| }</code></pre></div> |
| <p><br></p> |
| <h2 id="spans-and-error-reporting"><a href="#spans-and-error-reporting">Spans and error reporting</a></h2> |
| <p>The token-based procedural macro API provides great control over where the |
| compiler’s error messages are displayed in user code. Consider the error the |
| user sees if one of their field types does not implement <code>HeapSize</code>.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="attribute">#[derive(HeapSize)] |
| </span><span class="kw">struct </span>Broken { |
| ok: String, |
| bad: std::thread::Thread, |
| }</code></pre></div> |
| <p>By tracking span information all the way through the expansion of a |
| procedural macro as shown in the <code>heapsize</code> example, token-based macros in |
| Syn are able to trigger errors that directly pinpoint the source of the |
| problem.</p> |
| <div class="example-wrap"><pre class="language-text"><code>error[E0277]: the trait bound `std::thread::Thread: HeapSize` is not satisfied |
| --> src/main.rs:7:5 |
| | |
| 7 | bad: std::thread::Thread, |
| | ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `HeapSize` is not implemented for `Thread`</code></pre></div><br> |
| <h2 id="parsing-a-custom-syntax"><a href="#parsing-a-custom-syntax">Parsing a custom syntax</a></h2> |
| <p>The <a href="https://github.com/dtolnay/syn/tree/master/examples/lazy-static"><code>lazy-static</code></a> example directory shows the implementation of a |
| <code>functionlike!(...)</code> procedural macro in which the input tokens are parsed |
| using Syn’s parsing API.</p> |
| <p>The example reimplements the popular <code>lazy_static</code> crate from crates.io as a |
| procedural macro.</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="macro">lazy_static! </span>{ |
| <span class="kw">static </span><span class="kw-2">ref </span>USERNAME: Regex = Regex::new(<span class="string">"^[a-z0-9_-]{3,16}$"</span>).unwrap(); |
| }</code></pre></div> |
| <p>The implementation shows how to trigger custom warnings and error messages |
| on the macro input.</p> |
| <div class="example-wrap"><pre class="language-text"><code>warning: come on, pick a more creative name |
| --> src/main.rs:10:16 |
| | |
| 10 | static ref FOO: String = "lazy_static".to_owned(); |
| | ^^^</code></pre></div><br> |
| <h2 id="testing"><a href="#testing">Testing</a></h2> |
| <p>When testing macros, we often care not just that the macro can be used |
| successfully but also that when the macro is provided with invalid input it |
| produces maximally helpful error messages. Consider using the <a href="https://github.com/dtolnay/trybuild"><code>trybuild</code></a> |
| crate to write tests for errors that are emitted by your macro or errors |
| detected by the Rust compiler in the expanded code following misuse of the |
| macro. Such tests help avoid regressions from later refactors that |
| mistakenly make an error no longer trigger or be less helpful than it used |
| to be.</p> |
| <br> |
| <h2 id="debugging"><a href="#debugging">Debugging</a></h2> |
| <p>When developing a procedural macro it can be helpful to look at what the |
| generated code looks like. Use <code>cargo rustc -- -Zunstable-options --pretty=expanded</code> or the <a href="https://github.com/dtolnay/cargo-expand"><code>cargo expand</code></a> subcommand.</p> |
| <p>To show the expanded code for some crate that uses your procedural macro, |
| run <code>cargo expand</code> from that crate. To show the expanded code for one of |
| your own test cases, run <code>cargo expand --test the_test_case</code> where the last |
| argument is the name of the test file without the <code>.rs</code> extension.</p> |
| <p>This write-up by Brandon W Maister discusses debugging in more detail: |
| <a href="https://quodlibetor.github.io/posts/debugging-rusts-new-custom-derive-system/">Debugging Rust’s new Custom Derive system</a>.</p> |
| <br> |
| <h2 id="optional-features"><a href="#optional-features">Optional features</a></h2> |
| <p>Syn puts a lot of functionality behind optional features in order to |
| optimize compile time for the most common use cases. The following features |
| are available.</p> |
| <ul> |
| <li><strong><code>derive</code></strong> <em>(enabled by default)</em> — Data structures for representing the |
| possible input to a derive macro, including structs and enums and types.</li> |
| <li><strong><code>full</code></strong> — Data structures for representing the syntax tree of all valid |
| Rust source code, including items and expressions.</li> |
| <li><strong><code>parsing</code></strong> <em>(enabled by default)</em> — Ability to parse input tokens into |
| a syntax tree node of a chosen type.</li> |
| <li><strong><code>printing</code></strong> <em>(enabled by default)</em> — Ability to print a syntax tree |
| node as tokens of Rust source code.</li> |
| <li><strong><code>visit</code></strong> — Trait for traversing a syntax tree.</li> |
| <li><strong><code>visit-mut</code></strong> — Trait for traversing and mutating in place a syntax |
| tree.</li> |
| <li><strong><code>fold</code></strong> — Trait for transforming an owned syntax tree.</li> |
| <li><strong><code>clone-impls</code></strong> <em>(enabled by default)</em> — Clone impls for all syntax tree |
| types.</li> |
| <li><strong><code>extra-traits</code></strong> — Debug, Eq, PartialEq, Hash impls for all syntax tree |
| types.</li> |
| <li><strong><code>proc-macro</code></strong> <em>(enabled by default)</em> — Runtime dependency on the |
| dynamic library libproc_macro from rustc toolchain.</li> |
| </ul> |
| </div></details><h2 id="modules" class="small-section-header"><a href="#modules">Modules</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="mod" href="buffer/index.html" title="syn::buffer mod">buffer</a></div><div class="item-right docblock-short">A stably addressed token buffer supporting efficient traversal based on a |
| cheaply copyable cursor.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="ext/index.html" title="syn::ext mod">ext</a></div><div class="item-right docblock-short">Extension traits to provide parsing methods on foreign types.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="meta/index.html" title="syn::meta mod">meta</a></div><div class="item-right docblock-short">Facility for interpreting structured content inside of an <code>Attribute</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="parse/index.html" title="syn::parse mod">parse</a></div><div class="item-right docblock-short">Parsing interface for parsing a token stream into a syntax tree node.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="punctuated/index.html" title="syn::punctuated mod">punctuated</a></div><div class="item-right docblock-short">A punctuated sequence of syntax tree nodes separated by punctuation.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="spanned/index.html" title="syn::spanned mod">spanned</a></div><div class="item-right docblock-short">A trait that can provide the <code>Span</code> of the complete contents of a syntax |
| tree node.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="token/index.html" title="syn::token mod">token</a></div><div class="item-right docblock-short">Tokens representing Rust punctuation, keywords, and delimiters.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="visit/index.html" title="syn::visit mod">visit</a></div><div class="item-right docblock-short">Syntax tree traversal to walk a shared borrow of a syntax tree.</div></div><div class="item-row"><div class="item-left module-item"><a class="mod" href="visit_mut/index.html" title="syn::visit_mut mod">visit_mut</a></div><div class="item-right docblock-short">Syntax tree traversal to mutate an exclusive borrow of a syntax tree in |
| place.</div></div></div><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.Token.html" title="syn::Token macro">Token</a></div><div class="item-right docblock-short">A type-macro that expands to the name of the Rust type representation of a |
| given token.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.braced.html" title="syn::braced macro">braced</a></div><div class="item-right docblock-short">Parse a set of curly braces and expose their content to subsequent parsers.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.bracketed.html" title="syn::bracketed macro">bracketed</a></div><div class="item-right docblock-short">Parse a set of square brackets and expose their content to subsequent |
| parsers.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.custom_keyword.html" title="syn::custom_keyword macro">custom_keyword</a></div><div class="item-right docblock-short">Define a type that supports parsing and printing a given identifier as if it |
| were a keyword.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.custom_punctuation.html" title="syn::custom_punctuation macro">custom_punctuation</a></div><div class="item-right docblock-short">Define a type that supports parsing and printing a multi-character symbol |
| as if it were a punctuation token.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.parenthesized.html" title="syn::parenthesized macro">parenthesized</a></div><div class="item-right docblock-short">Parse a set of parentheses and expose their content to subsequent parsers.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.parse_macro_input.html" title="syn::parse_macro_input macro">parse_macro_input</a></div><div class="item-right docblock-short">Parse the input TokenStream of a macro, triggering a compile error if the |
| tokens fail to parse.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.parse_quote.html" title="syn::parse_quote macro">parse_quote</a></div><div class="item-right docblock-short">Quasi-quotation macro that accepts input like the <a href="https://docs.rs/quote/1.0/quote/index.html"><code>quote!</code></a> macro but uses |
| type inference to figure out a return type for those tokens.</div></div><div class="item-row"><div class="item-left module-item"><a class="macro" href="macro.parse_quote_spanned.html" title="syn::parse_quote_spanned macro">parse_quote_spanned</a></div><div class="item-right docblock-short">This macro is <a href="macro.parse_quote.html" title="parse_quote!"><code>parse_quote!</code></a> + <a href="../quote/macro.quote_spanned.html" title="quote::quote_spanned"><code>quote_spanned!</code></a>.</div></div></div><h2 id="structs" class="small-section-header"><a href="#structs">Structs</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Abi.html" title="syn::Abi struct">Abi</a></div><div class="item-right docblock-short">The binary interface of a function: <code>extern "C"</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.AngleBracketedGenericArguments.html" title="syn::AngleBracketedGenericArguments struct">AngleBracketedGenericArguments</a></div><div class="item-right docblock-short">Angle bracketed arguments of a path segment: the <code><K, V></code> in <code>HashMap<K, V></code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Arm.html" title="syn::Arm struct">Arm</a></div><div class="item-right docblock-short">One arm of a <code>match</code> expression: <code>0..=10 => { return true; }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.AssocConst.html" title="syn::AssocConst struct">AssocConst</a></div><div class="item-right docblock-short">An equality constraint on an associated constant: the <code>PANIC = false</code> in |
| <code>Trait<PANIC = false></code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.AssocType.html" title="syn::AssocType struct">AssocType</a></div><div class="item-right docblock-short">A binding (equality constraint) on an associated type: the <code>Item = u8</code> |
| in <code>Iterator<Item = u8></code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Attribute.html" title="syn::Attribute struct">Attribute</a></div><div class="item-right docblock-short">An attribute, like <code>#[repr(transparent)]</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.BareFnArg.html" title="syn::BareFnArg struct">BareFnArg</a></div><div class="item-right docblock-short">An argument in a function type: the <code>usize</code> in <code>fn(usize) -> bool</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.BareVariadic.html" title="syn::BareVariadic struct">BareVariadic</a></div><div class="item-right docblock-short">The variadic argument of a function pointer like <code>fn(usize, ...)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Block.html" title="syn::Block struct">Block</a></div><div class="item-right docblock-short">A braced block containing Rust statements.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.BoundLifetimes.html" title="syn::BoundLifetimes struct">BoundLifetimes</a></div><div class="item-right docblock-short">A set of bound lifetimes: <code>for<'a, 'b, 'c></code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ConstParam.html" title="syn::ConstParam struct">ConstParam</a></div><div class="item-right docblock-short">A const generic parameter: <code>const LENGTH: usize</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Constraint.html" title="syn::Constraint struct">Constraint</a></div><div class="item-right docblock-short">An associated type bound: <code>Iterator<Item: Display></code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.DataEnum.html" title="syn::DataEnum struct">DataEnum</a></div><div class="item-right docblock-short">An enum input to a <code>proc_macro_derive</code> macro.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.DataStruct.html" title="syn::DataStruct struct">DataStruct</a></div><div class="item-right docblock-short">A struct input to a <code>proc_macro_derive</code> macro.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.DataUnion.html" title="syn::DataUnion struct">DataUnion</a></div><div class="item-right docblock-short">An untagged union input to a <code>proc_macro_derive</code> macro.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.DeriveInput.html" title="syn::DeriveInput struct">DeriveInput</a></div><div class="item-right docblock-short">Data structure sent to a <code>proc_macro_derive</code> macro.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Error.html" title="syn::Error struct">Error</a></div><div class="item-right docblock-short">Error returned when a Syn parser cannot parse the input tokens.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprArray.html" title="syn::ExprArray struct">ExprArray</a></div><div class="item-right docblock-short">A slice literal expression: <code>[a, b, c, d]</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprAssign.html" title="syn::ExprAssign struct">ExprAssign</a></div><div class="item-right docblock-short">An assignment expression: <code>a = compute()</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprAsync.html" title="syn::ExprAsync struct">ExprAsync</a></div><div class="item-right docblock-short">An async block: <code>async { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprAwait.html" title="syn::ExprAwait struct">ExprAwait</a></div><div class="item-right docblock-short">An await expression: <code>fut.await</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprBinary.html" title="syn::ExprBinary struct">ExprBinary</a></div><div class="item-right docblock-short">A binary operation: <code>a + b</code>, <code>a += b</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprBlock.html" title="syn::ExprBlock struct">ExprBlock</a></div><div class="item-right docblock-short">A blocked scope: <code>{ ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprBreak.html" title="syn::ExprBreak struct">ExprBreak</a></div><div class="item-right docblock-short">A <code>break</code>, with an optional label to break and an optional |
| expression.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprCall.html" title="syn::ExprCall struct">ExprCall</a></div><div class="item-right docblock-short">A function call expression: <code>invoke(a, b)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprCast.html" title="syn::ExprCast struct">ExprCast</a></div><div class="item-right docblock-short">A cast expression: <code>foo as f64</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprClosure.html" title="syn::ExprClosure struct">ExprClosure</a></div><div class="item-right docblock-short">A closure expression: <code>|a, b| a + b</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprConst.html" title="syn::ExprConst struct">ExprConst</a></div><div class="item-right docblock-short">A const block: <code>const { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprContinue.html" title="syn::ExprContinue struct">ExprContinue</a></div><div class="item-right docblock-short">A <code>continue</code>, with an optional label.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprField.html" title="syn::ExprField struct">ExprField</a></div><div class="item-right docblock-short">Access of a named struct field (<code>obj.k</code>) or unnamed tuple struct |
| field (<code>obj.0</code>).</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprForLoop.html" title="syn::ExprForLoop struct">ExprForLoop</a></div><div class="item-right docblock-short">A for loop: <code>for pat in expr { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprGroup.html" title="syn::ExprGroup struct">ExprGroup</a></div><div class="item-right docblock-short">An expression contained within invisible delimiters.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprIf.html" title="syn::ExprIf struct">ExprIf</a></div><div class="item-right docblock-short">An <code>if</code> expression with an optional <code>else</code> block: <code>if expr { ... } else { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprIndex.html" title="syn::ExprIndex struct">ExprIndex</a></div><div class="item-right docblock-short">A square bracketed indexing expression: <code>vector[2]</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprInfer.html" title="syn::ExprInfer struct">ExprInfer</a></div><div class="item-right docblock-short">The inferred value of a const generic argument, denoted <code>_</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprLet.html" title="syn::ExprLet struct">ExprLet</a></div><div class="item-right docblock-short">A <code>let</code> guard: <code>let Some(x) = opt</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprLit.html" title="syn::ExprLit struct">ExprLit</a></div><div class="item-right docblock-short">A literal in place of an expression: <code>1</code>, <code>"foo"</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprLoop.html" title="syn::ExprLoop struct">ExprLoop</a></div><div class="item-right docblock-short">Conditionless loop: <code>loop { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprMacro.html" title="syn::ExprMacro struct">ExprMacro</a></div><div class="item-right docblock-short">A macro invocation expression: <code>format!("{}", q)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprMatch.html" title="syn::ExprMatch struct">ExprMatch</a></div><div class="item-right docblock-short">A <code>match</code> expression: <code>match n { Some(n) => {}, None => {} }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprMethodCall.html" title="syn::ExprMethodCall struct">ExprMethodCall</a></div><div class="item-right docblock-short">A method call expression: <code>x.foo::<T>(a, b)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprParen.html" title="syn::ExprParen struct">ExprParen</a></div><div class="item-right docblock-short">A parenthesized expression: <code>(a + b)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprPath.html" title="syn::ExprPath struct">ExprPath</a></div><div class="item-right docblock-short">A path like <code>std::mem::replace</code> possibly containing generic |
| parameters and a qualified self-type.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprRange.html" title="syn::ExprRange struct">ExprRange</a></div><div class="item-right docblock-short">A range expression: <code>1..2</code>, <code>1..</code>, <code>..2</code>, <code>1..=2</code>, <code>..=2</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprReference.html" title="syn::ExprReference struct">ExprReference</a></div><div class="item-right docblock-short">A referencing operation: <code>&a</code> or <code>&mut a</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprRepeat.html" title="syn::ExprRepeat struct">ExprRepeat</a></div><div class="item-right docblock-short">An array literal constructed from one repeated element: <code>[0u8; N]</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprReturn.html" title="syn::ExprReturn struct">ExprReturn</a></div><div class="item-right docblock-short">A <code>return</code>, with an optional value to be returned.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprStruct.html" title="syn::ExprStruct struct">ExprStruct</a></div><div class="item-right docblock-short">A struct literal expression: <code>Point { x: 1, y: 1 }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprTry.html" title="syn::ExprTry struct">ExprTry</a></div><div class="item-right docblock-short">A try-expression: <code>expr?</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprTryBlock.html" title="syn::ExprTryBlock struct">ExprTryBlock</a></div><div class="item-right docblock-short">A try block: <code>try { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprTuple.html" title="syn::ExprTuple struct">ExprTuple</a></div><div class="item-right docblock-short">A tuple expression: <code>(a, b, c, d)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprUnary.html" title="syn::ExprUnary struct">ExprUnary</a></div><div class="item-right docblock-short">A unary operation: <code>!x</code>, <code>*x</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprUnsafe.html" title="syn::ExprUnsafe struct">ExprUnsafe</a></div><div class="item-right docblock-short">An unsafe block: <code>unsafe { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprWhile.html" title="syn::ExprWhile struct">ExprWhile</a></div><div class="item-right docblock-short">A while loop: <code>while expr { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ExprYield.html" title="syn::ExprYield struct">ExprYield</a></div><div class="item-right docblock-short">A yield expression: <code>yield expr</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Field.html" title="syn::Field struct">Field</a></div><div class="item-right docblock-short">A field of a struct or enum variant.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.FieldPat.html" title="syn::FieldPat struct">FieldPat</a></div><div class="item-right docblock-short">A single field in a struct pattern.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.FieldValue.html" title="syn::FieldValue struct">FieldValue</a></div><div class="item-right docblock-short">A field-value pair in a struct literal.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.FieldsNamed.html" title="syn::FieldsNamed struct">FieldsNamed</a></div><div class="item-right docblock-short">Named fields of a struct or struct variant such as <code>Point { x: f64, y: f64 }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.FieldsUnnamed.html" title="syn::FieldsUnnamed struct">FieldsUnnamed</a></div><div class="item-right docblock-short">Unnamed fields of a tuple struct or tuple variant such as <code>Some(T)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.File.html" title="syn::File struct">File</a></div><div class="item-right docblock-short">A complete file of Rust source code.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ForeignItemFn.html" title="syn::ForeignItemFn struct">ForeignItemFn</a></div><div class="item-right docblock-short">A foreign function in an <code>extern</code> block.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ForeignItemMacro.html" title="syn::ForeignItemMacro struct">ForeignItemMacro</a></div><div class="item-right docblock-short">A macro invocation within an extern block.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ForeignItemStatic.html" title="syn::ForeignItemStatic struct">ForeignItemStatic</a></div><div class="item-right docblock-short">A foreign static item in an <code>extern</code> block: <code>static ext: u8</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ForeignItemType.html" title="syn::ForeignItemType struct">ForeignItemType</a></div><div class="item-right docblock-short">A foreign type in an <code>extern</code> block: <code>type void</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Generics.html" title="syn::Generics struct">Generics</a></div><div class="item-right docblock-short">Lifetimes and type parameters attached to a declaration of a function, |
| enum, trait, etc.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Ident.html" title="syn::Ident struct">Ident</a></div><div class="item-right docblock-short">A word of Rust code, which may be a keyword or legal variable name.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ImplGenerics.html" title="syn::ImplGenerics struct">ImplGenerics</a></div><div class="item-right docblock-short">Returned by <code>Generics::split_for_impl</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ImplItemConst.html" title="syn::ImplItemConst struct">ImplItemConst</a></div><div class="item-right docblock-short">An associated constant within an impl block.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ImplItemFn.html" title="syn::ImplItemFn struct">ImplItemFn</a></div><div class="item-right docblock-short">An associated function within an impl block.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ImplItemMacro.html" title="syn::ImplItemMacro struct">ImplItemMacro</a></div><div class="item-right docblock-short">A macro invocation within an impl block.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ImplItemType.html" title="syn::ImplItemType struct">ImplItemType</a></div><div class="item-right docblock-short">An associated type within an impl block.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Index.html" title="syn::Index struct">Index</a></div><div class="item-right docblock-short">The index of an unnamed tuple struct field.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemConst.html" title="syn::ItemConst struct">ItemConst</a></div><div class="item-right docblock-short">A constant item: <code>const MAX: u16 = 65535</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemEnum.html" title="syn::ItemEnum struct">ItemEnum</a></div><div class="item-right docblock-short">An enum definition: <code>enum Foo<A, B> { A(A), B(B) }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemExternCrate.html" title="syn::ItemExternCrate struct">ItemExternCrate</a></div><div class="item-right docblock-short">An <code>extern crate</code> item: <code>extern crate serde</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemFn.html" title="syn::ItemFn struct">ItemFn</a></div><div class="item-right docblock-short">A free-standing function: <code>fn process(n: usize) -> Result<()> { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemForeignMod.html" title="syn::ItemForeignMod struct">ItemForeignMod</a></div><div class="item-right docblock-short">A block of foreign items: <code>extern "C" { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemImpl.html" title="syn::ItemImpl struct">ItemImpl</a></div><div class="item-right docblock-short">An impl block providing trait or associated items: <code>impl<A> Trait for Data<A> { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemMacro.html" title="syn::ItemMacro struct">ItemMacro</a></div><div class="item-right docblock-short">A macro invocation, which includes <code>macro_rules!</code> definitions.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemMod.html" title="syn::ItemMod struct">ItemMod</a></div><div class="item-right docblock-short">A module or module declaration: <code>mod m</code> or <code>mod m { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemStatic.html" title="syn::ItemStatic struct">ItemStatic</a></div><div class="item-right docblock-short">A static item: <code>static BIKE: Shed = Shed(42)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemStruct.html" title="syn::ItemStruct struct">ItemStruct</a></div><div class="item-right docblock-short">A struct definition: <code>struct Foo<A> { x: A }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemTrait.html" title="syn::ItemTrait struct">ItemTrait</a></div><div class="item-right docblock-short">A trait definition: <code>pub trait Iterator { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemTraitAlias.html" title="syn::ItemTraitAlias struct">ItemTraitAlias</a></div><div class="item-right docblock-short">A trait alias: <code>pub trait SharableIterator = Iterator + Sync</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemType.html" title="syn::ItemType struct">ItemType</a></div><div class="item-right docblock-short">A type alias: <code>type Result<T> = std::result::Result<T, MyError></code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemUnion.html" title="syn::ItemUnion struct">ItemUnion</a></div><div class="item-right docblock-short">A union definition: <code>union Foo<A, B> { x: A, y: B }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ItemUse.html" title="syn::ItemUse struct">ItemUse</a></div><div class="item-right docblock-short">A use declaration: <code>use std::collections::HashMap</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Label.html" title="syn::Label struct">Label</a></div><div class="item-right docblock-short">A lifetime labeling a <code>for</code>, <code>while</code>, or <code>loop</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Lifetime.html" title="syn::Lifetime struct">Lifetime</a></div><div class="item-right docblock-short">A Rust lifetime: <code>'a</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LifetimeParam.html" title="syn::LifetimeParam struct">LifetimeParam</a></div><div class="item-right docblock-short">A lifetime definition: <code>'a: 'b + 'c + 'd</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LitBool.html" title="syn::LitBool struct">LitBool</a></div><div class="item-right docblock-short">A boolean literal: <code>true</code> or <code>false</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LitByte.html" title="syn::LitByte struct">LitByte</a></div><div class="item-right docblock-short">A byte literal: <code>b'f'</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LitByteStr.html" title="syn::LitByteStr struct">LitByteStr</a></div><div class="item-right docblock-short">A byte string literal: <code>b"foo"</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LitChar.html" title="syn::LitChar struct">LitChar</a></div><div class="item-right docblock-short">A character literal: <code>'a'</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LitFloat.html" title="syn::LitFloat struct">LitFloat</a></div><div class="item-right docblock-short">A floating point literal: <code>1f64</code> or <code>1.0e10f64</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LitInt.html" title="syn::LitInt struct">LitInt</a></div><div class="item-right docblock-short">An integer literal: <code>1</code> or <code>1u16</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LitStr.html" title="syn::LitStr struct">LitStr</a></div><div class="item-right docblock-short">A UTF-8 string literal: <code>"foo"</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Local.html" title="syn::Local struct">Local</a></div><div class="item-right docblock-short">A local <code>let</code> binding: <code>let x: u64 = s.parse()?</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.LocalInit.html" title="syn::LocalInit struct">LocalInit</a></div><div class="item-right docblock-short">The expression assigned in a local <code>let</code> binding, including optional |
| diverging <code>else</code> block.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Macro.html" title="syn::Macro struct">Macro</a></div><div class="item-right docblock-short">A macro invocation: <code>println!("{}", mac)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.MetaList.html" title="syn::MetaList struct">MetaList</a></div><div class="item-right docblock-short">A structured list within an attribute, like <code>derive(Copy, Clone)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.MetaNameValue.html" title="syn::MetaNameValue struct">MetaNameValue</a></div><div class="item-right docblock-short">A name-value pair within an attribute, like <code>feature = "nightly"</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.ParenthesizedGenericArguments.html" title="syn::ParenthesizedGenericArguments struct">ParenthesizedGenericArguments</a></div><div class="item-right docblock-short">Arguments of a function path segment: the <code>(A, B) -> C</code> in <code>Fn(A,B) -> C</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatConst.html" title="syn::PatConst struct">PatConst</a></div><div class="item-right docblock-short">A const block: <code>const { ... }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatIdent.html" title="syn::PatIdent struct">PatIdent</a></div><div class="item-right docblock-short">A pattern that binds a new variable: <code>ref mut binding @ SUBPATTERN</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatLit.html" title="syn::PatLit struct">PatLit</a></div><div class="item-right docblock-short">A literal in place of an expression: <code>1</code>, <code>"foo"</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatMacro.html" title="syn::PatMacro struct">PatMacro</a></div><div class="item-right docblock-short">A macro invocation expression: <code>format!("{}", q)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatOr.html" title="syn::PatOr struct">PatOr</a></div><div class="item-right docblock-short">A pattern that matches any one of a set of cases.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatParen.html" title="syn::PatParen struct">PatParen</a></div><div class="item-right docblock-short">A parenthesized pattern: <code>(A | B)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatPath.html" title="syn::PatPath struct">PatPath</a></div><div class="item-right docblock-short">A path like <code>std::mem::replace</code> possibly containing generic |
| parameters and a qualified self-type.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatRange.html" title="syn::PatRange struct">PatRange</a></div><div class="item-right docblock-short">A range expression: <code>1..2</code>, <code>1..</code>, <code>..2</code>, <code>1..=2</code>, <code>..=2</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatReference.html" title="syn::PatReference struct">PatReference</a></div><div class="item-right docblock-short">A reference pattern: <code>&mut var</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatRest.html" title="syn::PatRest struct">PatRest</a></div><div class="item-right docblock-short">The dots in a tuple or slice pattern: <code>[0, 1, ..]</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatSlice.html" title="syn::PatSlice struct">PatSlice</a></div><div class="item-right docblock-short">A dynamically sized slice pattern: <code>[a, b, ref i @ .., y, z]</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatStruct.html" title="syn::PatStruct struct">PatStruct</a></div><div class="item-right docblock-short">A struct or struct variant pattern: <code>Variant { x, y, .. }</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatTuple.html" title="syn::PatTuple struct">PatTuple</a></div><div class="item-right docblock-short">A tuple pattern: <code>(a, b)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatTupleStruct.html" title="syn::PatTupleStruct struct">PatTupleStruct</a></div><div class="item-right docblock-short">A tuple struct or tuple variant pattern: <code>Variant(x, y, .., z)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatType.html" title="syn::PatType struct">PatType</a></div><div class="item-right docblock-short">A type ascription pattern: <code>foo: f64</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PatWild.html" title="syn::PatWild struct">PatWild</a></div><div class="item-right docblock-short">A pattern that matches any value: <code>_</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Path.html" title="syn::Path struct">Path</a></div><div class="item-right docblock-short">A path at which a named item is exported (e.g. <code>std::collections::HashMap</code>).</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PathSegment.html" title="syn::PathSegment struct">PathSegment</a></div><div class="item-right docblock-short">A segment of a path together with any path arguments on that segment.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PredicateLifetime.html" title="syn::PredicateLifetime struct">PredicateLifetime</a></div><div class="item-right docblock-short">A lifetime predicate in a <code>where</code> clause: <code>'a: 'b + 'c</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.PredicateType.html" title="syn::PredicateType struct">PredicateType</a></div><div class="item-right docblock-short">A type predicate in a <code>where</code> clause: <code>for<'c> Foo<'c>: Trait<'c></code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.QSelf.html" title="syn::QSelf struct">QSelf</a></div><div class="item-right docblock-short">The explicit Self type in a qualified path: the <code>T</code> in <code><T as Display>::fmt</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Receiver.html" title="syn::Receiver struct">Receiver</a></div><div class="item-right docblock-short">The <code>self</code> argument of an associated method.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Signature.html" title="syn::Signature struct">Signature</a></div><div class="item-right docblock-short">A function signature in a trait or implementation: <code>unsafe fn initialize(&self)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.StmtMacro.html" title="syn::StmtMacro struct">StmtMacro</a></div><div class="item-right docblock-short">A macro invocation in statement position.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TraitBound.html" title="syn::TraitBound struct">TraitBound</a></div><div class="item-right docblock-short">A trait used as a bound on a type parameter.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TraitItemConst.html" title="syn::TraitItemConst struct">TraitItemConst</a></div><div class="item-right docblock-short">An associated constant within the definition of a trait.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TraitItemFn.html" title="syn::TraitItemFn struct">TraitItemFn</a></div><div class="item-right docblock-short">An associated function within the definition of a trait.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TraitItemMacro.html" title="syn::TraitItemMacro struct">TraitItemMacro</a></div><div class="item-right docblock-short">A macro invocation within the definition of a trait.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TraitItemType.html" title="syn::TraitItemType struct">TraitItemType</a></div><div class="item-right docblock-short">An associated type within the definition of a trait.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Turbofish.html" title="syn::Turbofish struct">Turbofish</a></div><div class="item-right docblock-short">Returned by <code>TypeGenerics::as_turbofish</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeArray.html" title="syn::TypeArray struct">TypeArray</a></div><div class="item-right docblock-short">A fixed size array type: <code>[T; n]</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeBareFn.html" title="syn::TypeBareFn struct">TypeBareFn</a></div><div class="item-right docblock-short">A bare function type: <code>fn(usize) -> bool</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeGenerics.html" title="syn::TypeGenerics struct">TypeGenerics</a></div><div class="item-right docblock-short">Returned by <code>Generics::split_for_impl</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeGroup.html" title="syn::TypeGroup struct">TypeGroup</a></div><div class="item-right docblock-short">A type contained within invisible delimiters.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeImplTrait.html" title="syn::TypeImplTrait struct">TypeImplTrait</a></div><div class="item-right docblock-short">An <code>impl Bound1 + Bound2 + Bound3</code> type where <code>Bound</code> is a trait or |
| a lifetime.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeInfer.html" title="syn::TypeInfer struct">TypeInfer</a></div><div class="item-right docblock-short">Indication that a type should be inferred by the compiler: <code>_</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeMacro.html" title="syn::TypeMacro struct">TypeMacro</a></div><div class="item-right docblock-short">A macro in the type position.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeNever.html" title="syn::TypeNever struct">TypeNever</a></div><div class="item-right docblock-short">The never type: <code>!</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeParam.html" title="syn::TypeParam struct">TypeParam</a></div><div class="item-right docblock-short">A generic type parameter: <code>T: Into<String></code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeParen.html" title="syn::TypeParen struct">TypeParen</a></div><div class="item-right docblock-short">A parenthesized type equivalent to the inner type.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypePath.html" title="syn::TypePath struct">TypePath</a></div><div class="item-right docblock-short">A path like <code>std::slice::Iter</code>, optionally qualified with a |
| self-type as in <code><Vec<T> as SomeTrait>::Associated</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypePtr.html" title="syn::TypePtr struct">TypePtr</a></div><div class="item-right docblock-short">A raw pointer type: <code>*const T</code> or <code>*mut T</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeReference.html" title="syn::TypeReference struct">TypeReference</a></div><div class="item-right docblock-short">A reference type: <code>&'a T</code> or <code>&'a mut T</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeSlice.html" title="syn::TypeSlice struct">TypeSlice</a></div><div class="item-right docblock-short">A dynamically sized slice type: <code>[T]</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeTraitObject.html" title="syn::TypeTraitObject struct">TypeTraitObject</a></div><div class="item-right docblock-short">A trait object type <code>dyn Bound1 + Bound2 + Bound3</code> where <code>Bound</code> is a |
| trait or a lifetime.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.TypeTuple.html" title="syn::TypeTuple struct">TypeTuple</a></div><div class="item-right docblock-short">A tuple type: <code>(A, B, C, String)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.UseGlob.html" title="syn::UseGlob struct">UseGlob</a></div><div class="item-right docblock-short">A glob import in a <code>use</code> item: <code>*</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.UseGroup.html" title="syn::UseGroup struct">UseGroup</a></div><div class="item-right docblock-short">A braced group of imports in a <code>use</code> item: <code>{A, B, C}</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.UseName.html" title="syn::UseName struct">UseName</a></div><div class="item-right docblock-short">An identifier imported by a <code>use</code> item: <code>HashMap</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.UsePath.html" title="syn::UsePath struct">UsePath</a></div><div class="item-right docblock-short">A path prefix of imports in a <code>use</code> item: <code>std::...</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.UseRename.html" title="syn::UseRename struct">UseRename</a></div><div class="item-right docblock-short">An renamed identifier imported by a <code>use</code> item: <code>HashMap as Map</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Variadic.html" title="syn::Variadic struct">Variadic</a></div><div class="item-right docblock-short">The variadic argument of a foreign function.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.Variant.html" title="syn::Variant struct">Variant</a></div><div class="item-right docblock-short">An enum variant.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.VisRestricted.html" title="syn::VisRestricted struct">VisRestricted</a></div><div class="item-right docblock-short">A visibility level restricted to some path: <code>pub(self)</code> or |
| <code>pub(super)</code> or <code>pub(crate)</code> or <code>pub(in some::module)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="struct" href="struct.WhereClause.html" title="syn::WhereClause struct">WhereClause</a></div><div class="item-right docblock-short">A <code>where</code> clause in a definition: <code>where T: Deserialize<'de>, D: 'static</code>.</div></div></div><h2 id="enums" class="small-section-header"><a href="#enums">Enums</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.AttrStyle.html" title="syn::AttrStyle enum">AttrStyle</a></div><div class="item-right docblock-short">Distinguishes between attributes that decorate an item and attributes |
| that are contained within an item.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.BinOp.html" title="syn::BinOp enum">BinOp</a></div><div class="item-right docblock-short">A binary operator: <code>+</code>, <code>+=</code>, <code>&</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Data.html" title="syn::Data enum">Data</a></div><div class="item-right docblock-short">The storage of a struct, enum or union data structure.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Expr.html" title="syn::Expr enum">Expr</a></div><div class="item-right docblock-short">A Rust expression.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.FieldMutability.html" title="syn::FieldMutability enum">FieldMutability</a></div><div class="item-right docblock-short">Unused, but reserved for RFC 3323 restrictions.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Fields.html" title="syn::Fields enum">Fields</a></div><div class="item-right docblock-short">Data stored within an enum variant or struct.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.FnArg.html" title="syn::FnArg enum">FnArg</a></div><div class="item-right docblock-short">An argument in a function signature: the <code>n: usize</code> in <code>fn f(n: usize)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.ForeignItem.html" title="syn::ForeignItem enum">ForeignItem</a></div><div class="item-right docblock-short">An item within an <code>extern</code> block.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.GenericArgument.html" title="syn::GenericArgument enum">GenericArgument</a></div><div class="item-right docblock-short">An individual generic argument, like <code>'a</code>, <code>T</code>, or <code>Item = T</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.GenericParam.html" title="syn::GenericParam enum">GenericParam</a></div><div class="item-right docblock-short">A generic type parameter, lifetime, or const generic: <code>T: Into<String></code>, |
| <code>'a: 'b</code>, <code>const LEN: usize</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.ImplItem.html" title="syn::ImplItem enum">ImplItem</a></div><div class="item-right docblock-short">An item within an impl block.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.ImplRestriction.html" title="syn::ImplRestriction enum">ImplRestriction</a></div><div class="item-right docblock-short">Unused, but reserved for RFC 3323 restrictions.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Item.html" title="syn::Item enum">Item</a></div><div class="item-right docblock-short">Things that can appear directly inside of a module or scope.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Lit.html" title="syn::Lit enum">Lit</a></div><div class="item-right docblock-short">A Rust literal such as a string or integer or boolean.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.MacroDelimiter.html" title="syn::MacroDelimiter enum">MacroDelimiter</a></div><div class="item-right docblock-short">A grouping token that surrounds a macro body: <code>m!(...)</code> or <code>m!{...}</code> or <code>m![...]</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Member.html" title="syn::Member enum">Member</a></div><div class="item-right docblock-short">A struct or tuple struct field accessed in a struct literal or field |
| expression.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Meta.html" title="syn::Meta enum">Meta</a></div><div class="item-right docblock-short">Content of a compile-time structured attribute.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Pat.html" title="syn::Pat enum">Pat</a></div><div class="item-right docblock-short">A pattern in a local binding, function signature, match expression, or |
| various other places.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.PathArguments.html" title="syn::PathArguments enum">PathArguments</a></div><div class="item-right docblock-short">Angle bracketed or parenthesized arguments of a path segment.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.RangeLimits.html" title="syn::RangeLimits enum">RangeLimits</a></div><div class="item-right docblock-short">Limit types of a range, inclusive or exclusive.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.ReturnType.html" title="syn::ReturnType enum">ReturnType</a></div><div class="item-right docblock-short">Return type of a function signature.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.StaticMutability.html" title="syn::StaticMutability enum">StaticMutability</a></div><div class="item-right docblock-short">The mutability of an <code>Item::Static</code> or <code>ForeignItem::Static</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Stmt.html" title="syn::Stmt enum">Stmt</a></div><div class="item-right docblock-short">A statement, usually ending in a semicolon.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.StrStyle.html" title="syn::StrStyle enum">StrStyle</a></div><div class="item-right docblock-short">The style of a string literal, either plain quoted or a raw string like |
| <code>r##"data"##</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.TraitBoundModifier.html" title="syn::TraitBoundModifier enum">TraitBoundModifier</a></div><div class="item-right docblock-short">A modifier on a trait bound, currently only used for the <code>?</code> in |
| <code>?Sized</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.TraitItem.html" title="syn::TraitItem enum">TraitItem</a></div><div class="item-right docblock-short">An item declaration within the definition of a trait.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Type.html" title="syn::Type enum">Type</a></div><div class="item-right docblock-short">The possible types that a Rust value could have.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.TypeParamBound.html" title="syn::TypeParamBound enum">TypeParamBound</a></div><div class="item-right docblock-short">A trait or lifetime used as a bound on a type parameter.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.UnOp.html" title="syn::UnOp enum">UnOp</a></div><div class="item-right docblock-short">A unary operator: <code>*</code>, <code>!</code>, <code>-</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.UseTree.html" title="syn::UseTree enum">UseTree</a></div><div class="item-right docblock-short">A suffix of an import tree in a <code>use</code> item: <code>Type as Renamed</code> or <code>*</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.Visibility.html" title="syn::Visibility enum">Visibility</a></div><div class="item-right docblock-short">The visibility level of an item: inherited or <code>pub</code> or |
| <code>pub(restricted)</code>.</div></div><div class="item-row"><div class="item-left module-item"><a class="enum" href="enum.WherePredicate.html" title="syn::WherePredicate enum">WherePredicate</a></div><div class="item-right docblock-short">A single predicate in a <code>where</code> clause: <code>T: Deserialize<'de></code>.</div></div></div><h2 id="functions" class="small-section-header"><a href="#functions">Functions</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="fn" href="fn.parse.html" title="syn::parse fn">parse</a></div><div class="item-right docblock-short">Parse tokens of source code into the chosen syntax tree node.</div></div><div class="item-row"><div class="item-left module-item"><a class="fn" href="fn.parse2.html" title="syn::parse2 fn">parse2</a></div><div class="item-right docblock-short">Parse a proc-macro2 token stream into the chosen syntax tree node.</div></div><div class="item-row"><div class="item-left module-item"><a class="fn" href="fn.parse_file.html" title="syn::parse_file fn">parse_file</a></div><div class="item-right docblock-short">Parse the content of a file of Rust code.</div></div><div class="item-row"><div class="item-left module-item"><a class="fn" href="fn.parse_str.html" title="syn::parse_str fn">parse_str</a></div><div class="item-right docblock-short">Parse a string of Rust code into the chosen syntax tree node.</div></div></div><h2 id="types" class="small-section-header"><a href="#types">Type Definitions</a></h2><div class="item-table"><div class="item-row"><div class="item-left module-item"><a class="type" href="type.Result.html" title="syn::Result type">Result</a></div><div class="item-right docblock-short">The result of a Syn parser.</div></div></div></section></div></main><div id="rustdoc-vars" data-root-path="../" data-current-crate="syn" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
