Auto Generated Documentation
This commit is contained in:
github-actions[bot]
+76
-101
@@ -1,143 +1,118 @@
|
||||
<!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="Parsing interface for parsing a token stream into a syntax tree node."><meta name="keywords" content="rust, rustlang, rust-lang, parse"><title>syn::parse - Rust</title><link rel="stylesheet" type="text/css" href="../../normalize.css"><link rel="stylesheet" type="text/css" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../light.css" id="themeStyle"><link rel="stylesheet" type="text/css" href="../../dark.css" disabled ><link rel="stylesheet" type="text/css" href="../../ayu.css" disabled ><script id="default-settings"></script><script src="../../storage.js"></script><script src="../../crates.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="icon" type="image/svg+xml" href="../../favicon.svg">
|
||||
<link rel="alternate icon" type="image/png" href="../../favicon-16x16.png">
|
||||
<link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><style type="text/css">#crate-search{background-image:url("../../down-arrow.svg");}</style></head><body class="rustdoc mod"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu" role="button">☰</div><a href='../../syn/index.html'><div class='logo-container rust-logo'><img src='../../rust-logo.png' alt='logo'></div></a><p class="location">Module parse</p><div class="sidebar-elems"><div class="block items"><ul><li><a href="#modules">Modules</a></li><li><a href="#structs">Structs</a></li><li><a href="#traits">Traits</a></li><li><a href="#types">Type Definitions</a></li></ul></div><p class="location"><a href="../index.html">syn</a></p><div id="sidebar-vars" data-name="parse" data-ty="mod" data-relpath="../"></div><script defer src="../sidebar-items.js"></script></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu"><img src="../../brush.svg" width="18" height="18" alt="Pick another theme!"></button><div id="theme-choices" role="menu"></div></div><nav class="sub"><form class="search-form"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" disabled autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><button type="button" class="help-button">?</button>
|
||||
<a id="settings-menu" href="../../settings.html"><img src="../../wheel.svg" width="18" height="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class="fqn"><span class="in-band">Module <a href="../index.html">syn</a>::<wbr><a class="mod" href="">parse</a><button id="copy-path" onclick="copy_path(this)">⎘</button></span><span class="out-of-band"><span id="render-detail"><a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span><a class="srclink" href="../../src/syn/parse.rs.html#1-1287" title="goto source code">[src]</a></span></h1><div class="docblock"><p>Parsing interface for parsing a token stream into a syntax tree node.</p>
|
||||
<p>Parsing in Syn is built on parser functions that take in a <a href="type.ParseStream.html" title="ParseStream"><code>ParseStream</code></a>
|
||||
and produce a <a href="type.Result.html"><code>Result<T></code></a> where <code>T</code> is some syntax tree node. Underlying
|
||||
<!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="Parsing interface for parsing a token stream into a syntax tree node."><title>syn::parse - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-46132b98.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="syn" data-themes="" data-resource-suffix="" data-rustdoc-version="1.85.1 (4eb161250 2025-03-15)" data-channel="1.85.1" data-search-js="search-75f5ac3e.js" data-settings-js="settings-0f613d39.js" ><script src="../../static.files/storage-59e33391.js"></script><script defer src="../sidebar-items.js"></script><script defer src="../../static.files/main-5f194d8c.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-893ab5e7.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-6580c154.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc mod"><!--[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" title="show sidebar"></button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../syn/index.html">syn</a><span class="version">2.0.100</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">Module parse</a></h2><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#example" title="Example">Example</a></li><li><a href="#the-synparse-functions" title="The `syn::parse*` functions">The <code>syn::parse*</code> functions</a></li><li><a href="#the-parser-trait" title="The `Parser` trait">The <code>Parser</code> trait</a></li></ul><h3><a href="#modules">Module Items</a></h3><ul class="block"><li><a href="#modules" title="Modules">Modules</a></li><li><a href="#structs" title="Structs">Structs</a></li><li><a href="#traits" title="Traits">Traits</a></li><li><a href="#types" title="Type Aliases">Type Aliases</a></li></ul></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="../index.html">In crate syn</a></h2></div></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><span class="rustdoc-breadcrumbs"><a href="../index.html">syn</a></span><h1>Module <span>parse</span><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../../src/syn/parse.rs.html#1-1419">Source</a> </span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Parsing interface for parsing a token stream into a syntax tree node.</p>
|
||||
<p>Parsing in Syn is built on parser functions that take in a <a href="type.ParseStream.html" title="type syn::parse::ParseStream"><code>ParseStream</code></a>
|
||||
and produce a <a href="../type.Result.html" title="type syn::Result"><code>Result<T></code></a> where <code>T</code> is some syntax tree node. Underlying
|
||||
these parser functions is a lower level mechanism built around the
|
||||
<a href="../buffer/struct.Cursor.html"><code>Cursor</code></a> type. <code>Cursor</code> is a cheaply copyable cursor over a range of
|
||||
<a href="../buffer/struct.Cursor.html" title="struct syn::buffer::Cursor"><code>Cursor</code></a> type. <code>Cursor</code> is a cheaply copyable cursor over a range of
|
||||
tokens in a token stream.</p>
|
||||
<h1 id="example" class="section-header"><a href="#example">Example</a></h1>
|
||||
<h2 id="example"><a class="doc-anchor" href="#example">§</a>Example</h2>
|
||||
<p>Here is a snippet of parsing code to get a feel for the style of the
|
||||
library. We define data structures for a subset of Rust syntax including
|
||||
enums (not shown) and structs, then provide implementations of the <a href="trait.Parse.html" title="Parse"><code>Parse</code></a>
|
||||
enums (not shown) and structs, then provide implementations of the <a href="trait.Parse.html" title="trait syn::parse::Parse"><code>Parse</code></a>
|
||||
trait to parse these syntax tree data structures from a token stream.</p>
|
||||
<p>Once <code>Parse</code> impls have been defined, they can be called conveniently from a
|
||||
procedural macro through <a href="../macro.parse_macro_input.html"><code>parse_macro_input!</code></a> as shown at the bottom of
|
||||
procedural macro through <a href="../macro.parse_macro_input.html" title="macro syn::parse_macro_input"><code>parse_macro_input!</code></a> as shown at the bottom of
|
||||
the snippet. If the caller provides syntactically invalid input to the
|
||||
procedural macro, they will receive a helpful compiler error message
|
||||
pointing out the exact token that triggered the failure to parse.</p>
|
||||
|
||||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||||
<span class="kw">use</span> <span class="ident">proc_macro::TokenStream</span>;
|
||||
<span class="kw">use</span> <span class="ident">syn</span>::{<span class="ident">braced</span>, <span class="ident">parse_macro_input</span>, <span class="ident">token</span>, <span class="ident">Field</span>, <span class="ident">Ident</span>, <span class="prelude-ty">Result</span>, <span class="ident">Token</span>};
|
||||
<span class="kw">use</span> <span class="ident">syn::parse</span>::{<span class="ident">Parse</span>, <span class="ident">ParseStream</span>};
|
||||
<span class="kw">use</span> <span class="ident">syn::punctuated::Punctuated</span>;
|
||||
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>proc_macro::TokenStream;
|
||||
<span class="kw">use </span>syn::{braced, parse_macro_input, token, Field, Ident, <span class="prelude-ty">Result</span>, Token};
|
||||
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
|
||||
<span class="kw">use </span>syn::punctuated::Punctuated;
|
||||
|
||||
<span class="kw">enum</span> <span class="ident">Item</span> {
|
||||
<span class="ident">Struct</span>(<span class="ident">ItemStruct</span>),
|
||||
<span class="ident">Enum</span>(<span class="ident">ItemEnum</span>),
|
||||
<span class="kw">enum </span>Item {
|
||||
Struct(ItemStruct),
|
||||
Enum(ItemEnum),
|
||||
}
|
||||
|
||||
<span class="kw">struct</span> <span class="ident">ItemStruct</span> {
|
||||
<span class="ident">struct_token</span>: <span class="macro">Token!</span>[<span class="kw">struct</span>],
|
||||
<span class="ident">ident</span>: <span class="ident">Ident</span>,
|
||||
<span class="ident">brace_token</span>: <span class="ident">token::Brace</span>,
|
||||
<span class="ident">fields</span>: <span class="ident">Punctuated</span><span class="op"><</span><span class="ident">Field</span>, <span class="macro">Token!</span>[,]<span class="op">></span>,
|
||||
<span class="kw">struct </span>ItemStruct {
|
||||
struct_token: <span class="macro">Token!</span>[<span class="kw">struct</span>],
|
||||
ident: Ident,
|
||||
brace_token: token::Brace,
|
||||
fields: Punctuated<Field, <span class="macro">Token!</span>[,]>,
|
||||
}
|
||||
|
||||
<span class="kw">impl</span> <span class="ident">Parse</span> <span class="kw">for</span> <span class="ident">Item</span> {
|
||||
<span class="kw">fn</span> <span class="ident">parse</span>(<span class="ident">input</span>: <span class="ident">ParseStream</span>) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Result</span><span class="op"><</span><span class="self">Self</span><span class="op">></span> {
|
||||
<span class="kw">let</span> <span class="ident">lookahead</span> <span class="op">=</span> <span class="ident">input</span>.<span class="ident">lookahead1</span>();
|
||||
<span class="kw">if</span> <span class="ident">lookahead</span>.<span class="ident">peek</span>(<span class="macro">Token!</span>[<span class="kw">struct</span>]) {
|
||||
<span class="ident">input</span>.<span class="ident">parse</span>().<span class="ident">map</span>(<span class="ident">Item::Struct</span>)
|
||||
} <span class="kw">else</span> <span class="kw">if</span> <span class="ident">lookahead</span>.<span class="ident">peek</span>(<span class="macro">Token!</span>[<span class="kw">enum</span>]) {
|
||||
<span class="ident">input</span>.<span class="ident">parse</span>().<span class="ident">map</span>(<span class="ident">Item::Enum</span>)
|
||||
} <span class="kw">else</span> {
|
||||
<span class="prelude-val">Err</span>(<span class="ident">lookahead</span>.<span class="ident">error</span>())
|
||||
<span class="kw">impl </span>Parse <span class="kw">for </span>Item {
|
||||
<span class="kw">fn </span>parse(input: ParseStream) -> <span class="prelude-ty">Result</span><<span class="self">Self</span>> {
|
||||
<span class="kw">let </span>lookahead = input.lookahead1();
|
||||
<span class="kw">if </span>lookahead.peek(<span class="macro">Token!</span>[<span class="kw">struct</span>]) {
|
||||
input.parse().map(Item::Struct)
|
||||
} <span class="kw">else if </span>lookahead.peek(<span class="macro">Token!</span>[<span class="kw">enum</span>]) {
|
||||
input.parse().map(Item::Enum)
|
||||
} <span class="kw">else </span>{
|
||||
<span class="prelude-val">Err</span>(lookahead.error())
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
<span class="kw">impl</span> <span class="ident">Parse</span> <span class="kw">for</span> <span class="ident">ItemStruct</span> {
|
||||
<span class="kw">fn</span> <span class="ident">parse</span>(<span class="ident">input</span>: <span class="ident">ParseStream</span>) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Result</span><span class="op"><</span><span class="self">Self</span><span class="op">></span> {
|
||||
<span class="kw">let</span> <span class="ident">content</span>;
|
||||
<span class="prelude-val">Ok</span>(<span class="ident">ItemStruct</span> {
|
||||
<span class="ident">struct_token</span>: <span class="ident">input</span>.<span class="ident">parse</span>()<span class="question-mark">?</span>,
|
||||
<span class="ident">ident</span>: <span class="ident">input</span>.<span class="ident">parse</span>()<span class="question-mark">?</span>,
|
||||
<span class="ident">brace_token</span>: <span class="macro">braced!</span>(<span class="ident">content</span> <span class="kw">in</span> <span class="ident">input</span>),
|
||||
<span class="ident">fields</span>: <span class="ident">content</span>.<span class="ident">parse_terminated</span>(<span class="ident">Field::parse_named</span>)<span class="question-mark">?</span>,
|
||||
<span class="kw">impl </span>Parse <span class="kw">for </span>ItemStruct {
|
||||
<span class="kw">fn </span>parse(input: ParseStream) -> <span class="prelude-ty">Result</span><<span class="self">Self</span>> {
|
||||
<span class="kw">let </span>content;
|
||||
<span class="prelude-val">Ok</span>(ItemStruct {
|
||||
struct_token: input.parse()<span class="question-mark">?</span>,
|
||||
ident: input.parse()<span class="question-mark">?</span>,
|
||||
brace_token: <span class="macro">braced!</span>(content <span class="kw">in </span>input),
|
||||
fields: content.parse_terminated(Field::parse_named, <span class="macro">Token!</span>[,])<span class="question-mark">?</span>,
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
<span class="attribute">#[<span class="ident">proc_macro</span>]</span>
|
||||
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">my_macro</span>(<span class="ident">tokens</span>: <span class="ident">TokenStream</span>) <span class="op">-</span><span class="op">></span> <span class="ident">TokenStream</span> {
|
||||
<span class="kw">let</span> <span class="ident">input</span> <span class="op">=</span> <span class="macro">parse_macro_input!</span>(<span class="ident">tokens</span> <span class="kw">as</span> <span class="ident">Item</span>);
|
||||
<span class="attr">#[proc_macro]
|
||||
</span><span class="kw">pub fn </span>my_macro(tokens: TokenStream) -> TokenStream {
|
||||
<span class="kw">let </span>input = <span class="macro">parse_macro_input!</span>(tokens <span class="kw">as </span>Item);
|
||||
|
||||
<span class="comment">/* ... */</span>
|
||||
}</pre></div>
|
||||
<h1 id="the-synparse-functions" class="section-header"><a href="#the-synparse-functions">The <code>syn::parse*</code> functions</a></h1>
|
||||
<p>The <a href="../fn.parse.html"><code>syn::parse</code></a>, <a href="../fn.parse2.html"><code>syn::parse2</code></a>, and <a href="../fn.parse_str.html"><code>syn::parse_str</code></a> functions serve
|
||||
<span class="comment">/* ... */
|
||||
</span>}</code></pre></div>
|
||||
<h2 id="the-synparse-functions"><a class="doc-anchor" href="#the-synparse-functions">§</a>The <code>syn::parse*</code> functions</h2>
|
||||
<p>The <a href="../fn.parse.html" title="fn syn::parse"><code>syn::parse</code></a>, <a href="../fn.parse2.html" title="fn syn::parse2"><code>syn::parse2</code></a>, and <a href="../fn.parse_str.html" title="fn syn::parse_str"><code>syn::parse_str</code></a> functions serve
|
||||
as an entry point for parsing syntax tree nodes that can be parsed in an
|
||||
obvious default way. These functions can return any syntax tree node that
|
||||
implements the <a href="trait.Parse.html" title="Parse"><code>Parse</code></a> trait, which includes most types in Syn.</p>
|
||||
implements the <a href="trait.Parse.html" title="trait syn::parse::Parse"><code>Parse</code></a> trait, which includes most types in Syn.</p>
|
||||
|
||||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||||
<span class="kw">use</span> <span class="ident">syn::Type</span>;
|
||||
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::Type;
|
||||
|
||||
<span class="kw">let</span> <span class="ident">t</span>: <span class="ident">Type</span> <span class="op">=</span> <span class="ident">syn::parse_str</span>(<span class="string">"std::collections::HashMap<String, Value>"</span>)<span class="question-mark">?</span>;</pre></div>
|
||||
<p>The <a href="../macro.parse_quote.html"><code>parse_quote!</code></a> macro also uses this approach.</p>
|
||||
<h1 id="the-parser-trait" class="section-header"><a href="#the-parser-trait">The <code>Parser</code> trait</a></h1>
|
||||
<span class="kw">let </span>t: Type = syn::parse_str(<span class="string">"std::collections::HashMap<String, Value>"</span>)<span class="question-mark">?</span>;</code></pre></div>
|
||||
<p>The <a href="../macro.parse_quote.html" title="macro syn::parse_quote"><code>parse_quote!</code></a> macro also uses this approach.</p>
|
||||
<h2 id="the-parser-trait"><a class="doc-anchor" href="#the-parser-trait">§</a>The <code>Parser</code> trait</h2>
|
||||
<p>Some types can be parsed in several ways depending on context. For example
|
||||
an <a href="../struct.Attribute.html"><code>Attribute</code></a> can be either “outer” like <code>#[...]</code> or “inner” like
|
||||
<code>#![...]</code> and parsing the wrong one would be a bug. Similarly <a href="../punctuated/index.html"><code>Punctuated</code></a>
|
||||
an <a href="../struct.Attribute.html" title="struct syn::Attribute"><code>Attribute</code></a> can be either “outer” like <code>#[...]</code> or “inner” like
|
||||
<code>#![...]</code> and parsing the wrong one would be a bug. Similarly <a href="../punctuated/index.html" title="mod syn::punctuated"><code>Punctuated</code></a>
|
||||
may or may not allow trailing punctuation, and parsing it the wrong way
|
||||
would either reject valid input or accept invalid input.</p>
|
||||
<p>The <code>Parse</code> trait is not implemented in these cases because there is no good
|
||||
behavior to consider the default.</p>
|
||||
|
||||
<div class='information'><div class='tooltip compile_fail'>ⓘ</div></div><div class="example-wrap"><pre class="rust rust-example-rendered compile_fail">
|
||||
<span class="comment">// Can't parse `Punctuated` without knowing whether trailing punctuation</span>
|
||||
<span class="comment">// should be allowed in this context.</span>
|
||||
<span class="kw">let</span> <span class="ident">path</span>: <span class="ident">Punctuated</span><span class="op"><</span><span class="ident">PathSegment</span>, <span class="macro">Token!</span>[::]<span class="op">></span> <span class="op">=</span> <span class="ident">syn::parse</span>(<span class="ident">tokens</span>)<span class="question-mark">?</span>;</pre></div>
|
||||
<div class="example-wrap compile_fail"><a href="#" class="tooltip" title="This example deliberately fails to compile">ⓘ</a><pre class="rust rust-example-rendered"><code><span class="comment">// Can't parse `Punctuated` without knowing whether trailing punctuation
|
||||
// should be allowed in this context.
|
||||
</span><span class="kw">let </span>path: Punctuated<PathSegment, <span class="macro">Token!</span>[::]> = syn::parse(tokens)<span class="question-mark">?</span>;</code></pre></div>
|
||||
<p>In these cases the types provide a choice of parser functions rather than a
|
||||
single <code>Parse</code> implementation, and those parser functions can be invoked
|
||||
through the <a href="trait.Parser.html" title="Parser"><code>Parser</code></a> trait.</p>
|
||||
through the <a href="trait.Parser.html" title="trait syn::parse::Parser"><code>Parser</code></a> trait.</p>
|
||||
|
||||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||||
<span class="kw">use</span> <span class="ident">proc_macro::TokenStream</span>;
|
||||
<span class="kw">use</span> <span class="ident">syn::parse::Parser</span>;
|
||||
<span class="kw">use</span> <span class="ident">syn::punctuated::Punctuated</span>;
|
||||
<span class="kw">use</span> <span class="ident">syn</span>::{<span class="ident">Attribute</span>, <span class="ident">Expr</span>, <span class="ident">PathSegment</span>, <span class="prelude-ty">Result</span>, <span class="ident">Token</span>};
|
||||
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>proc_macro::TokenStream;
|
||||
<span class="kw">use </span>syn::parse::Parser;
|
||||
<span class="kw">use </span>syn::punctuated::Punctuated;
|
||||
<span class="kw">use </span>syn::{Attribute, Expr, PathSegment, <span class="prelude-ty">Result</span>, Token};
|
||||
|
||||
<span class="kw">fn</span> <span class="ident">call_some_parser_methods</span>(<span class="ident">input</span>: <span class="ident">TokenStream</span>) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Result</span><span class="op"><</span>()<span class="op">></span> {
|
||||
<span class="comment">// Parse a nonempty sequence of path segments separated by `::` punctuation</span>
|
||||
<span class="comment">// with no trailing punctuation.</span>
|
||||
<span class="kw">let</span> <span class="ident">tokens</span> <span class="op">=</span> <span class="ident">input</span>.<span class="ident">clone</span>();
|
||||
<span class="kw">let</span> <span class="ident">parser</span> <span class="op">=</span> <span class="ident">Punctuated</span>::<span class="op"><</span><span class="ident">PathSegment</span>, <span class="macro">Token!</span>[::]<span class="op">></span><span class="ident">::parse_separated_nonempty</span>;
|
||||
<span class="kw">let</span> <span class="ident">_path</span> <span class="op">=</span> <span class="ident">parser</span>.<span class="ident">parse</span>(<span class="ident">tokens</span>)<span class="question-mark">?</span>;
|
||||
<span class="kw">fn </span>call_some_parser_methods(input: TokenStream) -> <span class="prelude-ty">Result</span><()> {
|
||||
<span class="comment">// Parse a nonempty sequence of path segments separated by `::` punctuation
|
||||
// with no trailing punctuation.
|
||||
</span><span class="kw">let </span>tokens = input.clone();
|
||||
<span class="kw">let </span>parser = Punctuated::<PathSegment, <span class="macro">Token!</span>[::]>::parse_separated_nonempty;
|
||||
<span class="kw">let </span>_path = parser.parse(tokens)<span class="question-mark">?</span>;
|
||||
|
||||
<span class="comment">// Parse a possibly empty sequence of expressions terminated by commas with</span>
|
||||
<span class="comment">// an optional trailing punctuation.</span>
|
||||
<span class="kw">let</span> <span class="ident">tokens</span> <span class="op">=</span> <span class="ident">input</span>.<span class="ident">clone</span>();
|
||||
<span class="kw">let</span> <span class="ident">parser</span> <span class="op">=</span> <span class="ident">Punctuated</span>::<span class="op"><</span><span class="ident">Expr</span>, <span class="macro">Token!</span>[,]<span class="op">></span><span class="ident">::parse_terminated</span>;
|
||||
<span class="kw">let</span> <span class="ident">_args</span> <span class="op">=</span> <span class="ident">parser</span>.<span class="ident">parse</span>(<span class="ident">tokens</span>)<span class="question-mark">?</span>;
|
||||
<span class="comment">// Parse a possibly empty sequence of expressions terminated by commas with
|
||||
// an optional trailing punctuation.
|
||||
</span><span class="kw">let </span>tokens = input.clone();
|
||||
<span class="kw">let </span>parser = Punctuated::<Expr, <span class="macro">Token!</span>[,]>::parse_terminated;
|
||||
<span class="kw">let </span>_args = parser.parse(tokens)<span class="question-mark">?</span>;
|
||||
|
||||
<span class="comment">// Parse zero or more outer attributes but not inner attributes.</span>
|
||||
<span class="kw">let</span> <span class="ident">tokens</span> <span class="op">=</span> <span class="ident">input</span>.<span class="ident">clone</span>();
|
||||
<span class="kw">let</span> <span class="ident">parser</span> <span class="op">=</span> <span class="ident">Attribute::parse_outer</span>;
|
||||
<span class="kw">let</span> <span class="ident">_attrs</span> <span class="op">=</span> <span class="ident">parser</span>.<span class="ident">parse</span>(<span class="ident">tokens</span>)<span class="question-mark">?</span>;
|
||||
<span class="comment">// Parse zero or more outer attributes but not inner attributes.
|
||||
</span><span class="kw">let </span>tokens = input.clone();
|
||||
<span class="kw">let </span>parser = Attribute::parse_outer;
|
||||
<span class="kw">let </span>_attrs = parser.parse(tokens)<span class="question-mark">?</span>;
|
||||
|
||||
<span class="prelude-val">Ok</span>(())
|
||||
}</pre></div>
|
||||
<hr />
|
||||
<p><em>This module is available only if Syn is built with the <code>"parsing"</code> feature.</em></p>
|
||||
</div><h2 id="modules" class="section-header"><a href="#modules">Modules</a></h2>
|
||||
<table><tr class="module-item"><td><a class="mod" href="discouraged/index.html" title="syn::parse::discouraged mod">discouraged</a></td><td class="docblock-short"><p>Extensions to the parsing API with niche applicability.</p>
|
||||
</td></tr></table><h2 id="structs" class="section-header"><a href="#structs">Structs</a></h2>
|
||||
<table><tr class="module-item"><td><a class="struct" href="struct.Error.html" title="syn::parse::Error struct">Error</a></td><td class="docblock-short"><p>Error returned when a Syn parser cannot parse the input tokens.</p>
|
||||
</td></tr><tr class="module-item"><td><a class="struct" href="struct.Lookahead1.html" title="syn::parse::Lookahead1 struct">Lookahead1</a></td><td class="docblock-short"><p>Support for checking the next token in a stream to decide how to parse.</p>
|
||||
</td></tr><tr class="module-item"><td><a class="struct" href="struct.Nothing.html" title="syn::parse::Nothing struct">Nothing</a></td><td class="docblock-short"><p>An empty syntax tree node that consumes no tokens when parsed.</p>
|
||||
</td></tr><tr class="module-item"><td><a class="struct" href="struct.ParseBuffer.html" title="syn::parse::ParseBuffer struct">ParseBuffer</a></td><td class="docblock-short"><p>Cursor position within a buffered token stream.</p>
|
||||
</td></tr><tr class="module-item"><td><a class="struct" href="struct.StepCursor.html" title="syn::parse::StepCursor struct">StepCursor</a></td><td class="docblock-short"><p>Cursor state associated with speculative parsing.</p>
|
||||
</td></tr></table><h2 id="traits" class="section-header"><a href="#traits">Traits</a></h2>
|
||||
<table><tr class="module-item"><td><a class="trait" href="trait.Parse.html" title="syn::parse::Parse trait">Parse</a></td><td class="docblock-short"><p>Parsing interface implemented by all types that can be parsed in a default
|
||||
way from a token stream.</p>
|
||||
</td></tr><tr class="module-item"><td><a class="trait" href="trait.Parser.html" title="syn::parse::Parser trait">Parser</a></td><td class="docblock-short"><p>Parser that can parse Rust tokens into a particular syntax tree node.</p>
|
||||
</td></tr><tr class="module-item"><td><a class="trait" href="trait.Peek.html" title="syn::parse::Peek trait">Peek</a></td><td class="docblock-short"><p>Types that can be parsed by looking at just one token.</p>
|
||||
</td></tr></table><h2 id="types" class="section-header"><a href="#types">Type Definitions</a></h2>
|
||||
<table><tr class="module-item"><td><a class="type" href="type.ParseStream.html" title="syn::parse::ParseStream type">ParseStream</a></td><td class="docblock-short"><p>Input to a Syn parser function.</p>
|
||||
</td></tr><tr class="module-item"><td><a class="type" href="type.Result.html" title="syn::parse::Result type">Result</a></td><td class="docblock-short"><p>The result of a Syn parser.</p>
|
||||
</td></tr></table></section><section id="search" class="content hidden"></section><div id="rustdoc-vars" data-root-path="../../" data-current-crate="syn" data-search-index-js="../../search-index.js" data-search-js="../../search.js"></div>
|
||||
<script src="../../main.js"></script></body></html>
|
||||
}</code></pre></div>
|
||||
</div></details><h2 id="modules" class="section-header">Modules<a href="#modules" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="mod" href="discouraged/index.html" title="mod syn::parse::discouraged">discouraged</a></div><div class="desc docblock-short">Extensions to the parsing API with niche applicability.</div></li></ul><h2 id="structs" class="section-header">Structs<a href="#structs" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="struct" href="struct.End.html" title="struct syn::parse::End">End</a></div><div class="desc docblock-short">Pseudo-token used for peeking the end of a parse stream.</div></li><li><div class="item-name"><a class="struct" href="struct.Error.html" title="struct syn::parse::Error">Error</a></div><div class="desc docblock-short">Error returned when a Syn parser cannot parse the input tokens.</div></li><li><div class="item-name"><a class="struct" href="struct.Lookahead1.html" title="struct syn::parse::Lookahead1">Lookahead1</a></div><div class="desc docblock-short">Support for checking the next token in a stream to decide how to parse.</div></li><li><div class="item-name"><a class="struct" href="struct.Nothing.html" title="struct syn::parse::Nothing">Nothing</a></div><div class="desc docblock-short">An empty syntax tree node that consumes no tokens when parsed.</div></li><li><div class="item-name"><a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">Parse<wbr>Buffer</a></div><div class="desc docblock-short">Cursor position within a buffered token stream.</div></li><li><div class="item-name"><a class="struct" href="struct.StepCursor.html" title="struct syn::parse::StepCursor">Step<wbr>Cursor</a></div><div class="desc docblock-short">Cursor state associated with speculative parsing.</div></li></ul><h2 id="traits" class="section-header">Traits<a href="#traits" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="trait" href="trait.Parse.html" title="trait syn::parse::Parse">Parse</a></div><div class="desc docblock-short">Parsing interface implemented by all types that can be parsed in a default
|
||||
way from a token stream.</div></li><li><div class="item-name"><a class="trait" href="trait.Parser.html" title="trait syn::parse::Parser">Parser</a></div><div class="desc docblock-short">Parser that can parse Rust tokens into a particular syntax tree node.</div></li><li><div class="item-name"><a class="trait" href="trait.Peek.html" title="trait syn::parse::Peek">Peek</a></div><div class="desc docblock-short">Types that can be parsed by looking at just one token.</div></li></ul><h2 id="types" class="section-header">Type Aliases<a href="#types" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="type" href="type.ParseStream.html" title="type syn::parse::ParseStream">Parse<wbr>Stream</a></div><div class="desc docblock-short">Input to a Syn parser function.</div></li><li><div class="item-name"><a class="type" href="type.Result.html" title="type syn::parse::Result">Result</a></div><div class="desc docblock-short">The result of a Syn parser.</div></li></ul></section></div></main></body></html>
|
||||
Reference in New Issue
Block a user