| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro-error-attr-1.0.4/src/parse.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>parse.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../proc_macro_error_attr/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../proc_macro_error_attr/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use crate</span>::{Error, <span class="prelude-ty">Result</span>}; |
| <span class="kw">use </span>proc_macro2::{Delimiter, Ident, Span, TokenStream, TokenTree}; |
| <span class="kw">use </span>quote::ToTokens; |
| <span class="kw">use </span>std::iter::Peekable; |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>parse_input( |
| input: TokenStream, |
| ) -> <span class="prelude-ty">Result</span><(Vec<Attribute>, Vec<TokenTree>, TokenTree)> { |
| <span class="kw">let </span><span class="kw-2">mut </span>input = input.into_iter().peekable(); |
| <span class="kw">let </span><span class="kw-2">mut </span>attrs = Vec::new(); |
| |
| <span class="kw">while let </span><span class="prelude-val">Some</span>(attr) = parse_next_attr(<span class="kw-2">&mut </span>input)<span class="question-mark">? </span>{ |
| attrs.push(attr); |
| } |
| |
| <span class="kw">let </span>sig = parse_signature(<span class="kw-2">&mut </span>input); |
| <span class="kw">let </span>body = input.next().ok_or_else(|| { |
| Error::new( |
| Span::call_site(), |
| <span class="string">"`#[proc_macro_error]` can be applied only to functions"</span>.to_string(), |
| ) |
| })<span class="question-mark">?</span>; |
| |
| <span class="prelude-val">Ok</span>((attrs, sig, body)) |
| } |
| |
| <span class="kw">fn </span>parse_next_attr( |
| input: <span class="kw-2">&mut </span>Peekable<<span class="kw">impl </span>Iterator<Item = TokenTree>>, |
| ) -> <span class="prelude-ty">Result</span><<span class="prelude-ty">Option</span><Attribute>> { |
| <span class="kw">let </span>shebang = <span class="kw">match </span>input.peek() { |
| <span class="prelude-val">Some</span>(TokenTree::Punct(<span class="kw-2">ref </span>punct)) <span class="kw">if </span>punct.as_char() == <span class="string">'#' </span>=> input.next().unwrap(), |
| <span class="kw">_ </span>=> <span class="kw">return </span><span class="prelude-val">Ok</span>(<span class="prelude-val">None</span>), |
| }; |
| |
| <span class="kw">let </span>group = <span class="kw">match </span>input.peek() { |
| <span class="prelude-val">Some</span>(TokenTree::Group(<span class="kw-2">ref </span>group)) <span class="kw">if </span>group.delimiter() == Delimiter::Bracket => { |
| <span class="kw">let </span>res = group.clone(); |
| input.next(); |
| res |
| } |
| other => { |
| <span class="kw">let </span>span = other.map_or(Span::call_site(), |tt| tt.span()); |
| <span class="kw">return </span><span class="prelude-val">Err</span>(Error::new(span, <span class="string">"expected `[`"</span>.to_string())); |
| } |
| }; |
| |
| <span class="kw">let </span>path = <span class="kw">match </span>group.stream().into_iter().next() { |
| <span class="prelude-val">Some</span>(TokenTree::Ident(ident)) => <span class="prelude-val">Some</span>(ident), |
| <span class="kw">_ </span>=> <span class="prelude-val">None</span>, |
| }; |
| |
| <span class="prelude-val">Ok</span>(<span class="prelude-val">Some</span>(Attribute { |
| shebang, |
| group: TokenTree::Group(group), |
| path, |
| })) |
| } |
| |
| <span class="kw">fn </span>parse_signature(input: <span class="kw-2">&mut </span>Peekable<<span class="kw">impl </span>Iterator<Item = TokenTree>>) -> Vec<TokenTree> { |
| <span class="kw">let </span><span class="kw-2">mut </span>sig = Vec::new(); |
| <span class="kw">loop </span>{ |
| <span class="kw">match </span>input.peek() { |
| <span class="prelude-val">Some</span>(TokenTree::Group(<span class="kw-2">ref </span>group)) <span class="kw">if </span>group.delimiter() == Delimiter::Brace => { |
| <span class="kw">return </span>sig; |
| } |
| <span class="prelude-val">None </span>=> <span class="kw">return </span>sig, |
| <span class="kw">_ </span>=> sig.push(input.next().unwrap()), |
| } |
| } |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>Attribute { |
| <span class="kw">pub</span>(<span class="kw">crate</span>) shebang: TokenTree, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) group: TokenTree, |
| <span class="kw">pub</span>(<span class="kw">crate</span>) path: <span class="prelude-ty">Option</span><Ident>, |
| } |
| |
| <span class="kw">impl </span>Attribute { |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>path_is_ident(<span class="kw-2">&</span><span class="self">self</span>, ident: <span class="kw-2">&</span>str) -> bool { |
| <span class="self">self</span>.path.as_ref().map_or(<span class="bool-val">false</span>, |p| <span class="kw-2">*</span>p == ident) |
| } |
| } |
| |
| <span class="kw">impl </span>ToTokens <span class="kw">for </span>Attribute { |
| <span class="kw">fn </span>to_tokens(<span class="kw-2">&</span><span class="self">self</span>, ts: <span class="kw-2">&mut </span>TokenStream) { |
| <span class="self">self</span>.shebang.to_tokens(ts); |
| <span class="self">self</span>.group.to_tokens(ts); |
| } |
| } |
| </code></pre></div> |
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