edg-l/edlang
1
1
Fork 0
mirror of https://github.com/edg-l/edlang.git synced 2024-11-10 01:58:23 +00:00
Code Issues Packages Projects Releases Wiki Activity
edlang/syn/fn.parse.html

28 lines
5.6 KiB
HTML
Raw Normal View History

deploy: d99059405e7534be8cc5d2d985d63e2d8daa2bcc
2024-03-02 09:26:34 +00:00
<!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="Parse tokens of source code into the chosen syntax tree node."><title>parse in syn - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2"><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-ac92e1bbe349e143.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="1.76.0 (07dca489a 2024-02-04)" data-channel="1.76.0" data-search-js="search-2b6ce74ff89ae146.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../static.files/storage-f2adc0d6ca4d09fb.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-305769736d49e732.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-feafe1bb7466e4bd.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-16x16-8b506e7a72182f1c.png"><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc fn"><!--[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">&#9776;</button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../syn/index.html">syn</a><span class="version">2.0.52</span></h2></div><div class="sidebar-elems"></div></nav><div class="sidebar-resizer"></div>
deploy: cc1e3679829ec7c574392bace9092ffa4ecb73c2
2024-02-27 06:59:44 +00:00
<main><div class="width-limiter"><nav class="sub"><form class="search-form"><span></span><div id="sidebar-button" tabindex="-1"><a href="../syn/all.html" title="show sidebar"></a></div><input class="search-input" name="search" aria-label="Run search in the documentation" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" tabindex="-1"><a href="../help.html" title="help">?</a></div><div id="settings-menu" tabindex="-1"><a href="../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1>Function <a href="index.html">syn</a>::<wbr><a class="fn" href="#">parse</a><button id="copy-path" title="Copy item path to clipboard"><img src="../static.files/clipboard-7571035ce49a181d.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="src" href="../src/syn/lib.rs.html#896-898">source</a> · <button id="toggle-all-docs" title="collapse all docs">[<span>&#x2212;</span>]</button></span></div><pre class="rust item-decl"><code>pub fn parse&lt;T: <a class="trait" href="parse/trait.Parse.html" title="trait syn::parse::Parse">Parse</a>&gt;(tokens: <a class="struct" href="https://doc.rust-lang.org/1.76.0/proc_macro/struct.TokenStream.html" title="struct proc_macro::TokenStream">TokenStream</a>) -&gt; <a class="type" href="parse/type.Result.html" title="type syn::parse::Result">Result</a>&lt;T&gt;</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Parse tokens of source code into the chosen syntax tree node.</p>
deploy: 4a83cfd6f9c58b14a87234162281aad1aef83c3e
2024-02-13 06:38:44 +00:00
<p>This is preferred over parsing a string because tokens are able to preserve
information about where in the user’s code they were originally written (the
“span” of the token), possibly allowing the compiler to produce better error
messages.</p>
<p>This function parses a <code>proc_macro::TokenStream</code> which is the type used for
interop with the compiler in a procedural macro. To parse a
<code>proc_macro2::TokenStream</code>, use <a href="fn.parse2.html" title="fn syn::parse2"><code>syn::parse2</code></a> instead.</p>
<h2 id="examples"><a href="#examples">Examples</a></h2>
<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::DeriveInput;
<span class="attr">#[proc_macro_derive(MyMacro)]
</span><span class="kw">pub fn </span>my_macro(input: TokenStream) -&gt; TokenStream {
<span class="comment">// Parse the tokens into a syntax tree
</span><span class="kw">let </span>ast: DeriveInput = syn::parse(input).unwrap();
<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">// Convert into a token stream and return it
</span>expanded.into()
}</code></pre></div>
</div></details></section></div></main></body></html>
Reference in a new issue Copy permalink