edg-l/edlang
1
1
Fork 0
mirror of https://github.com/edg-l/edlang.git synced 2024-11-09 17:48:24 +00:00
Code Issues Packages Projects Releases Wiki Activity
edlang/syn/parse/struct.ParseBuffer.html
edg-l df146223dd deploy: b3bd34a9bb
2024-07-26 09:42:18 +00:00

505 lines
64 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!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="Cursor position within a buffered token stream."><title>ParseBuffer in syn::parse - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.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-76eba96aa4d2e634.css"><link rel="stylesheet" href="../../static.files/rustdoc-dd39b87e5fcfba68.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="1.80.0 (051478957 2024-07-21)" data-channel="1.80.0" data-search-js="search-d52510db62a78183.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../../static.files/storage-118b08c4c78b968e.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../static.files/main-20a3ad099b048cf2.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-df360f571f6edeae.css"></noscript><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 struct"><!--[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">2.0.72</span></h2></div><h2 class="location"><a href="#">ParseBuffer</a></h2><div class="sidebar-elems"><section><h3><a href="#implementations">Methods</a></h3><ul class="block method"><li><a href="#method.call">call</a></li><li><a href="#method.cursor">cursor</a></li><li><a href="#method.error">error</a></li><li><a href="#method.fork">fork</a></li><li><a href="#method.is_empty">is_empty</a></li><li><a href="#method.lookahead1">lookahead1</a></li><li><a href="#method.parse">parse</a></li><li><a href="#method.parse_terminated">parse_terminated</a></li><li><a href="#method.peek">peek</a></li><li><a href="#method.peek2">peek2</a></li><li><a href="#method.peek3">peek3</a></li><li><a href="#method.span">span</a></li><li><a href="#method.step">step</a></li></ul><h3><a href="#trait-implementations">Trait Implementations</a></h3><ul class="block trait-implementation"><li><a href="#impl-AnyDelimiter-for-ParseBuffer%3C'a%3E">AnyDelimiter</a></li><li><a href="#impl-Debug-for-ParseBuffer%3C'a%3E">Debug</a></li><li><a href="#impl-Display-for-ParseBuffer%3C'a%3E">Display</a></li><li><a href="#impl-Drop-for-ParseBuffer%3C'a%3E">Drop</a></li><li><a href="#impl-RefUnwindSafe-for-ParseBuffer%3C'a%3E">RefUnwindSafe</a></li><li><a href="#impl-Speculative-for-ParseBuffer%3C'a%3E">Speculative</a></li><li><a href="#impl-UnwindSafe-for-ParseBuffer%3C'a%3E">UnwindSafe</a></li></ul><h3><a href="#synthetic-implementations">Auto Trait Implementations</a></h3><ul class="block synthetic-implementation"><li><a href="#impl-Freeze-for-ParseBuffer%3C'a%3E">!Freeze</a></li><li><a href="#impl-Send-for-ParseBuffer%3C'a%3E">!Send</a></li><li><a href="#impl-Sync-for-ParseBuffer%3C'a%3E">!Sync</a></li><li><a href="#impl-Unpin-for-ParseBuffer%3C'a%3E">Unpin</a></li></ul><h3><a href="#blanket-implementations">Blanket Implementations</a></h3><ul class="block blanket-implementation"><li><a href="#impl-Any-for-T">Any</a></li><li><a href="#impl-Borrow%3CT%3E-for-T">Borrow&lt;T&gt;</a></li><li><a href="#impl-BorrowMut%3CT%3E-for-T">BorrowMut&lt;T&gt;</a></li><li><a href="#impl-From%3CT%3E-for-T">From&lt;T&gt;</a></li><li><a href="#impl-Into%3CU%3E-for-T">Into&lt;U&gt;</a></li><li><a href="#impl-ToString-for-T">ToString</a></li><li><a href="#impl-TryFrom%3CU%3E-for-T">TryFrom&lt;U&gt;</a></li><li><a href="#impl-TryInto%3CU%3E-for-T">TryInto&lt;U&gt;</a></li></ul></section><h2><a href="index.html">In syn::parse</a></h2></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"><h1>Struct <a href="../index.html">syn</a>::<wbr><a href="index.html">parse</a>::<wbr><a class="struct" href="#">ParseBuffer</a><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><span class="out-of-band"><a class="src" href="../../src/syn/parse.rs.html#246-262">source</a> · <button id="toggle-all-docs" title="collapse all docs">[<span>&#x2212;</span>]</button></span></div><pre class="rust item-decl"><code>pub struct ParseBuffer&lt;'a&gt; { <span class="comment">/* private fields */</span> }</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Cursor position within a buffered token stream.</p>
<p>This type is more commonly used through the type alias <a href="type.ParseStream.html" title="type syn::parse::ParseStream"><code>ParseStream</code></a> which
is an alias for <code>&amp;ParseBuffer</code>.</p>
<p><code>ParseStream</code> is the input type for all parser functions in Syn. They have
the signature <code>fn(ParseStream) -&gt; Result&lt;T&gt;</code>.</p>
<h3 id="calling-a-parser-function"><a class="doc-anchor" href="#calling-a-parser-function">§</a>Calling a parser function</h3>
<p>There is no public way to construct a <code>ParseBuffer</code>. Instead, if you are
looking to invoke a parser function that requires <code>ParseStream</code> as input,
you will need to go through one of the public parsing entry points.</p>
<ul>
<li>The <a href="../macro.parse_macro_input.html" title="macro syn::parse_macro_input"><code>parse_macro_input!</code></a> macro if parsing input of a procedural macro;</li>
<li>One of <a href="index.html#the-synparse-functions" title="mod syn::parse">the <code>syn::parse*</code> functions</a>; or</li>
<li>A method of the <a href="trait.Parser.html" title="trait syn::parse::Parser"><code>Parser</code></a> trait.</li>
</ul>
</div></details><h2 id="implementations" class="section-header">Implementations<a href="#implementations" class="anchor">§</a></h2><div id="implementations-list"><details class="toggle implementors-toggle" open><summary><section id="impl-ParseBuffer%3C'a%3E" class="impl"><a class="src rightside" href="../../src/syn/parse.rs.html#461-1157">source</a><a href="#impl-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.parse" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#464-466">source</a><h4 class="code-header">pub fn <a href="#method.parse" class="fn">parse</a>&lt;T: <a class="trait" href="trait.Parse.html" title="trait syn::parse::Parse">Parse</a>&gt;(&amp;self) -&gt; <a class="type" href="type.Result.html" title="type syn::parse::Result">Result</a>&lt;T&gt;</h4></section></summary><div class="docblock"><p>Parses a syntax tree node of type <code>T</code>, advancing the position of our
parse stream past it.</p>
</div></details><details class="toggle method-toggle" open><summary><section id="method.call" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#504-506">source</a><h4 class="code-header">pub fn <a href="#method.call" class="fn">call</a>&lt;T&gt;(
&amp;self,
function: <a class="primitive" href="https://doc.rust-lang.org/1.80.0/std/primitive.fn.html">fn</a>(_: <a class="type" href="type.ParseStream.html" title="type syn::parse::ParseStream">ParseStream</a>&lt;'_&gt;) -&gt; <a class="type" href="type.Result.html" title="type syn::parse::Result">Result</a>&lt;T&gt;,
) -&gt; <a class="type" href="type.Result.html" title="type syn::parse::Result">Result</a>&lt;T&gt;</h4></section></summary><div class="docblock"><p>Calls the given parser function to parse a syntax tree node of type <code>T</code>
from this stream.</p>
<h5 id="example"><a class="doc-anchor" href="#example">§</a>Example</h5>
<p>The parser below invokes <a href="../struct.Attribute.html#method.parse_outer" title="associated function syn::Attribute::parse_outer"><code>Attribute::parse_outer</code></a> to parse a vector of
zero or more outer attributes.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{Attribute, Ident, <span class="prelude-ty">Result</span>, Token};
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
<span class="comment">// Parses a unit struct with attributes.
//
// #[path = "s.tmpl"]
// struct S;
</span><span class="kw">struct </span>UnitStruct {
attrs: Vec&lt;Attribute&gt;,
struct_token: <span class="macro">Token!</span>[<span class="kw">struct</span>],
name: Ident,
semi_token: <span class="macro">Token!</span>[;],
}
<span class="kw">impl </span>Parse <span class="kw">for </span>UnitStruct {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="prelude-val">Ok</span>(UnitStruct {
attrs: input.call(Attribute::parse_outer)<span class="question-mark">?</span>,
struct_token: input.parse()<span class="question-mark">?</span>,
name: input.parse()<span class="question-mark">?</span>,
semi_token: input.parse()<span class="question-mark">?</span>,
})
}
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.peek" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#580-583">source</a><h4 class="code-header">pub fn <a href="#method.peek" class="fn">peek</a>&lt;T: <a class="trait" href="trait.Peek.html" title="trait syn::parse::Peek">Peek</a>&gt;(&amp;self, token: T) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.80.0/std/primitive.bool.html">bool</a></h4></section></summary><div class="docblock"><p>Looks at the next token in the parse stream to determine whether it
matches the requested type of token.</p>
<p>Does not advance the position of the parse stream.</p>
<h5 id="syntax"><a class="doc-anchor" href="#syntax">§</a>Syntax</h5>
<p>Note that this method does not use turbofish syntax. Pass the peek type
inside of parentheses.</p>
<ul>
<li><code>input.peek(Token![struct])</code></li>
<li><code>input.peek(Token![==])</code></li>
<li><code>input.peek(syn::Ident)</code> <em>(does not accept keywords)</em></li>
<li><code>input.peek(syn::Ident::peek_any)</code></li>
<li><code>input.peek(Lifetime)</code></li>
<li><code>input.peek(token::Brace)</code></li>
</ul>
<h5 id="example-1"><a class="doc-anchor" href="#example-1">§</a>Example</h5>
<p>In this example we finish parsing the list of supertraits when the next
token in the input is either <code>where</code> or an opening curly brace.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{braced, token, Generics, Ident, <span class="prelude-ty">Result</span>, Token, TypeParamBound};
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
<span class="kw">use </span>syn::punctuated::Punctuated;
<span class="comment">// Parses a trait definition containing no associated items.
//
// trait Marker&lt;'de, T&gt;: A + B&lt;'de&gt; where Box&lt;T&gt;: Clone {}
</span><span class="kw">struct </span>MarkerTrait {
trait_token: <span class="macro">Token!</span>[<span class="kw">trait</span>],
ident: Ident,
generics: Generics,
colon_token: <span class="prelude-ty">Option</span>&lt;<span class="macro">Token!</span>[:]&gt;,
supertraits: Punctuated&lt;TypeParamBound, <span class="macro">Token!</span>[+]&gt;,
brace_token: token::Brace,
}
<span class="kw">impl </span>Parse <span class="kw">for </span>MarkerTrait {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="kw">let </span>trait_token: <span class="macro">Token!</span>[<span class="kw">trait</span>] = input.parse()<span class="question-mark">?</span>;
<span class="kw">let </span>ident: Ident = input.parse()<span class="question-mark">?</span>;
<span class="kw">let </span><span class="kw-2">mut </span>generics: Generics = input.parse()<span class="question-mark">?</span>;
<span class="kw">let </span>colon_token: <span class="prelude-ty">Option</span>&lt;<span class="macro">Token!</span>[:]&gt; = input.parse()<span class="question-mark">?</span>;
<span class="kw">let </span><span class="kw-2">mut </span>supertraits = Punctuated::new();
<span class="kw">if </span>colon_token.is_some() {
<span class="kw">loop </span>{
supertraits.push_value(input.parse()<span class="question-mark">?</span>);
<span class="kw">if </span>input.peek(<span class="macro">Token!</span>[<span class="kw">where</span>]) || input.peek(token::Brace) {
<span class="kw">break</span>;
}
supertraits.push_punct(input.parse()<span class="question-mark">?</span>);
}
}
generics.where_clause = input.parse()<span class="question-mark">?</span>;
<span class="kw">let </span>content;
<span class="kw">let </span>empty_brace_token = <span class="macro">braced!</span>(content <span class="kw">in </span>input);
<span class="prelude-val">Ok</span>(MarkerTrait {
trait_token,
ident,
generics,
colon_token,
supertraits,
brace_token: empty_brace_token,
})
}
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.peek2" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#619-626">source</a><h4 class="code-header">pub fn <a href="#method.peek2" class="fn">peek2</a>&lt;T: <a class="trait" href="trait.Peek.html" title="trait syn::parse::Peek">Peek</a>&gt;(&amp;self, token: T) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.80.0/std/primitive.bool.html">bool</a></h4></section></summary><div class="docblock"><p>Looks at the second-next token in the parse stream.</p>
<p>This is commonly useful as a way to implement contextual keywords.</p>
<h5 id="example-2"><a class="doc-anchor" href="#example-2">§</a>Example</h5>
<p>This example needs to use <code>peek2</code> because the symbol <code>union</code> is not a
keyword in Rust. We can’t use just <code>peek</code> and decide to parse a union if
the very next token is <code>union</code>, because someone is free to write a <code>mod union</code> and a macro invocation that looks like <code>union::some_macro! { ... }</code>. In other words <code>union</code> is a contextual keyword.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{Ident, ItemUnion, Macro, <span class="prelude-ty">Result</span>, Token};
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
<span class="comment">// Parses either a union or a macro invocation.
</span><span class="kw">enum </span>UnionOrMacro {
<span class="comment">// union MaybeUninit&lt;T&gt; { uninit: (), value: T }
</span>Union(ItemUnion),
<span class="comment">// lazy_static! { ... }
</span>Macro(Macro),
}
<span class="kw">impl </span>Parse <span class="kw">for </span>UnionOrMacro {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="kw">if </span>input.peek(<span class="macro">Token!</span>[union]) &amp;&amp; input.peek2(Ident) {
input.parse().map(UnionOrMacro::Union)
} <span class="kw">else </span>{
input.parse().map(UnionOrMacro::Macro)
}
}
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.peek3" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#629-640">source</a><h4 class="code-header">pub fn <a href="#method.peek3" class="fn">peek3</a>&lt;T: <a class="trait" href="trait.Peek.html" title="trait syn::parse::Peek">Peek</a>&gt;(&amp;self, token: T) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.80.0/std/primitive.bool.html">bool</a></h4></section></summary><div class="docblock"><p>Looks at the third-next token in the parse stream.</p>
</div></details><details class="toggle method-toggle" open><summary><section id="method.parse_terminated" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#733-744">source</a><h4 class="code-header">pub fn <a href="#method.parse_terminated" class="fn">parse_terminated</a>&lt;T, P&gt;(
&amp;self,
parser: <a class="primitive" href="https://doc.rust-lang.org/1.80.0/std/primitive.fn.html">fn</a>(_: <a class="type" href="type.ParseStream.html" title="type syn::parse::ParseStream">ParseStream</a>&lt;'_&gt;) -&gt; <a class="type" href="type.Result.html" title="type syn::parse::Result">Result</a>&lt;T&gt;,
separator: P,
) -&gt; <a class="type" href="type.Result.html" title="type syn::parse::Result">Result</a>&lt;<a class="struct" href="../punctuated/struct.Punctuated.html" title="struct syn::punctuated::Punctuated">Punctuated</a>&lt;T, P::<a class="associatedtype" href="trait.Peek.html#associatedtype.Token" title="type syn::parse::Peek::Token">Token</a>&gt;&gt;<div class="where">where
P: <a class="trait" href="trait.Peek.html" title="trait syn::parse::Peek">Peek</a>,
P::<a class="associatedtype" href="trait.Peek.html#associatedtype.Token" title="type syn::parse::Peek::Token">Token</a>: <a class="trait" href="trait.Parse.html" title="trait syn::parse::Parse">Parse</a>,</div></h4></section></summary><div class="docblock"><p>Parses zero or more occurrences of <code>T</code> separated by punctuation of type
<code>P</code>, with optional trailing punctuation.</p>
<p>Parsing continues until the end of this parse stream. The entire content
of this parse stream must consist of <code>T</code> and <code>P</code>.</p>
<h5 id="example-3"><a class="doc-anchor" href="#example-3">§</a>Example</h5>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{parenthesized, token, Ident, <span class="prelude-ty">Result</span>, Token, Type};
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
<span class="kw">use </span>syn::punctuated::Punctuated;
<span class="comment">// Parse a simplified tuple struct syntax like:
//
// struct S(A, B);
</span><span class="kw">struct </span>TupleStruct {
struct_token: <span class="macro">Token!</span>[<span class="kw">struct</span>],
ident: Ident,
paren_token: token::Paren,
fields: Punctuated&lt;Type, <span class="macro">Token!</span>[,]&gt;,
semi_token: <span class="macro">Token!</span>[;],
}
<span class="kw">impl </span>Parse <span class="kw">for </span>TupleStruct {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="kw">let </span>content;
<span class="prelude-val">Ok</span>(TupleStruct {
struct_token: input.parse()<span class="question-mark">?</span>,
ident: input.parse()<span class="question-mark">?</span>,
paren_token: <span class="macro">parenthesized!</span>(content <span class="kw">in </span>input),
fields: content.parse_terminated(Type::parse, <span class="macro">Token!</span>[,])<span class="question-mark">?</span>,
semi_token: input.parse()<span class="question-mark">?</span>,
})
}
}</code></pre></div>
<h5 id="see-also"><a class="doc-anchor" href="#see-also">§</a>See also</h5>
<p>If your separator is anything more complicated than an invocation of the
<code>Token!</code> macro, this method won’t be applicable and you can instead
directly use <code>Punctuated</code>’s parser functions: <a href="../punctuated/struct.Punctuated.html#method.parse_terminated" title="associated function syn::punctuated::Punctuated::parse_terminated"><code>parse_terminated</code></a>,
<a href="../punctuated/struct.Punctuated.html#method.parse_separated_nonempty" title="associated function syn::punctuated::Punctuated::parse_separated_nonempty"><code>parse_separated_nonempty</code></a> etc.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{custom_keyword, Expr, <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">mod </span>kw {
<span class="macro">syn::custom_keyword!</span>(fin);
}
<span class="kw">struct </span>Fin(kw::fin, <span class="macro">Token!</span>[;]);
<span class="kw">impl </span>Parse <span class="kw">for </span>Fin {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="prelude-val">Ok</span>(<span class="self">Self</span>(input.parse()<span class="question-mark">?</span>, input.parse()<span class="question-mark">?</span>))
}
}
<span class="kw">struct </span>Thing {
steps: Punctuated&lt;Expr, Fin&gt;,
}
<span class="kw">impl </span>Parse <span class="kw">for </span>Thing {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="prelude-val">Ok</span>(Thing {
steps: Punctuated::parse_terminated(input)<span class="question-mark">?</span>,
})
<span class="comment">// or equivalently, this means the same thing:
</span>steps: input.call(Punctuated::parse_terminated)<span class="question-mark">?</span>,
}
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.is_empty" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#785-787">source</a><h4 class="code-header">pub fn <a href="#method.is_empty" class="fn">is_empty</a>(&amp;self) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.80.0/std/primitive.bool.html">bool</a></h4></section></summary><div class="docblock"><p>Returns whether there are no more tokens remaining to be parsed from
this stream.</p>
<p>This method returns true upon reaching the end of the content within a
set of delimiters, as well as at the end of the tokens provided to the
outermost parsing entry point.</p>
<h5 id="example-4"><a class="doc-anchor" href="#example-4">§</a>Example</h5>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{braced, token, Ident, Item, <span class="prelude-ty">Result</span>, Token};
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
<span class="comment">// Parses a Rust `mod m { ... }` containing zero or more items.
</span><span class="kw">struct </span>Mod {
mod_token: <span class="macro">Token!</span>[<span class="kw">mod</span>],
name: Ident,
brace_token: token::Brace,
items: Vec&lt;Item&gt;,
}
<span class="kw">impl </span>Parse <span class="kw">for </span>Mod {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="kw">let </span>content;
<span class="prelude-val">Ok</span>(Mod {
mod_token: input.parse()<span class="question-mark">?</span>,
name: input.parse()<span class="question-mark">?</span>,
brace_token: <span class="macro">braced!</span>(content <span class="kw">in </span>input),
items: {
<span class="kw">let </span><span class="kw-2">mut </span>items = Vec::new();
<span class="kw">while </span>!content.is_empty() {
items.push(content.parse()<span class="question-mark">?</span>);
}
items
},
})
}
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.lookahead1" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#830-832">source</a><h4 class="code-header">pub fn <a href="#method.lookahead1" class="fn">lookahead1</a>(&amp;self) -&gt; <a class="struct" href="struct.Lookahead1.html" title="struct syn::parse::Lookahead1">Lookahead1</a>&lt;'a&gt;</h4></section></summary><div class="docblock"><p>Constructs a helper for peeking at the next token in this stream and
building an error message if it is not one of a set of expected tokens.</p>
<h5 id="example-5"><a class="doc-anchor" href="#example-5">§</a>Example</h5>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{ConstParam, Ident, Lifetime, LifetimeParam, <span class="prelude-ty">Result</span>, Token, TypeParam};
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
<span class="comment">// A generic parameter, a single one of the comma-separated elements inside
// angle brackets in:
//
// fn f&lt;T: Clone, 'a, 'b: 'a, const N: usize&gt;() { ... }
//
// On invalid input, lookahead gives us a reasonable error message.
//
// error: expected one of: identifier, lifetime, `const`
// |
// 5 | fn f&lt;!Sized&gt;() {}
// | ^
</span><span class="kw">enum </span>GenericParam {
Type(TypeParam),
Lifetime(LifetimeParam),
Const(ConstParam),
}
<span class="kw">impl </span>Parse <span class="kw">for </span>GenericParam {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="kw">let </span>lookahead = input.lookahead1();
<span class="kw">if </span>lookahead.peek(Ident) {
input.parse().map(GenericParam::Type)
} <span class="kw">else if </span>lookahead.peek(Lifetime) {
input.parse().map(GenericParam::Lifetime)
} <span class="kw">else if </span>lookahead.peek(<span class="macro">Token!</span>[<span class="kw">const</span>]) {
input.parse().map(GenericParam::Const)
} <span class="kw">else </span>{
<span class="prelude-val">Err</span>(lookahead.error())
}
}
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.fork" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#960-969">source</a><h4 class="code-header">pub fn <a href="#method.fork" class="fn">fork</a>(&amp;self) -&gt; Self</h4></section></summary><div class="docblock"><p>Forks a parse stream so that parsing tokens out of either the original
or the fork does not advance the position of the other.</p>
<h5 id="performance"><a class="doc-anchor" href="#performance">§</a>Performance</h5>
<p>Forking a parse stream is a cheap fixed amount of work and does not
involve copying token buffers. Where you might hit performance problems
is if your macro ends up parsing a large amount of content more than
once.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="comment">// Do not do this.
</span><span class="kw">if </span>input.fork().parse::&lt;Expr&gt;().is_ok() {
<span class="kw">return </span>input.parse::&lt;Expr&gt;();
}</code></pre></div>
<p>As a rule, avoid parsing an unbounded amount of tokens out of a forked
parse stream. Only use a fork when the amount of work performed against
the fork is small and bounded.</p>
<p>When complex speculative parsing against the forked stream is
unavoidable, use <a href="discouraged/trait.Speculative.html" title="trait syn::parse::discouraged::Speculative"><code>parse::discouraged::Speculative</code></a> to advance the
original stream once the fork’s parse is determined to have been
successful.</p>
<p>For a lower level way to perform speculative parsing at the token level,
consider using <a href="struct.ParseBuffer.html#method.step" title="method syn::parse::ParseBuffer::step"><code>ParseStream::step</code></a> instead.</p>
<h5 id="example-6"><a class="doc-anchor" href="#example-6">§</a>Example</h5>
<p>The parse implementation shown here parses possibly restricted <code>pub</code>
visibilities.</p>
<ul>
<li><code>pub</code></li>
<li><code>pub(crate)</code></li>
<li><code>pub(self)</code></li>
<li><code>pub(super)</code></li>
<li><code>pub(in some::path)</code></li>
</ul>
<p>To handle the case of visibilities inside of tuple structs, the parser
needs to distinguish parentheses that specify visibility restrictions
from parentheses that form part of a tuple type.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">struct </span>S(<span class="kw">pub</span>(<span class="kw">crate</span>) A, <span class="kw">pub </span>(B, C));</code></pre></div>
<p>In this example input the first tuple struct element of <code>S</code> has
<code>pub(crate)</code> visibility while the second tuple struct element has <code>pub</code>
visibility; the parentheses around <code>(B, C)</code> are part of the type rather
than part of a visibility restriction.</p>
<p>The parser uses a forked parse stream to check the first token inside of
parentheses after the <code>pub</code> keyword. This is a small bounded amount of
work performed against the forked parse stream.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{parenthesized, token, Ident, Path, <span class="prelude-ty">Result</span>, Token};
<span class="kw">use </span>syn::ext::IdentExt;
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
<span class="kw">struct </span>PubVisibility {
pub_token: <span class="macro">Token!</span>[<span class="kw">pub</span>],
restricted: <span class="prelude-ty">Option</span>&lt;Restricted&gt;,
}
<span class="kw">struct </span>Restricted {
paren_token: token::Paren,
in_token: <span class="prelude-ty">Option</span>&lt;<span class="macro">Token!</span>[<span class="kw">in</span>]&gt;,
path: Path,
}
<span class="kw">impl </span>Parse <span class="kw">for </span>PubVisibility {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="kw">let </span>pub_token: <span class="macro">Token!</span>[<span class="kw">pub</span>] = input.parse()<span class="question-mark">?</span>;
<span class="kw">if </span>input.peek(token::Paren) {
<span class="kw">let </span>ahead = input.fork();
<span class="kw">let </span><span class="kw-2">mut </span>content;
<span class="macro">parenthesized!</span>(content <span class="kw">in </span>ahead);
<span class="kw">if </span>content.peek(<span class="macro">Token!</span>[<span class="kw">crate</span>])
|| content.peek(<span class="macro">Token!</span>[<span class="self">self</span>])
|| content.peek(<span class="macro">Token!</span>[<span class="kw">super</span>])
{
<span class="kw">return </span><span class="prelude-val">Ok</span>(PubVisibility {
pub_token,
restricted: <span class="prelude-val">Some</span>(Restricted {
paren_token: <span class="macro">parenthesized!</span>(content <span class="kw">in </span>input),
in_token: <span class="prelude-val">None</span>,
path: Path::from(content.call(Ident::parse_any)<span class="question-mark">?</span>),
}),
});
} <span class="kw">else if </span>content.peek(<span class="macro">Token!</span>[<span class="kw">in</span>]) {
<span class="kw">return </span><span class="prelude-val">Ok</span>(PubVisibility {
pub_token,
restricted: <span class="prelude-val">Some</span>(Restricted {
paren_token: <span class="macro">parenthesized!</span>(content <span class="kw">in </span>input),
in_token: <span class="prelude-val">Some</span>(content.parse()<span class="question-mark">?</span>),
path: content.call(Path::parse_mod_style)<span class="question-mark">?</span>,
}),
});
}
}
<span class="prelude-val">Ok</span>(PubVisibility {
pub_token,
restricted: <span class="prelude-val">None</span>,
})
}
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.error" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#999-1001">source</a><h4 class="code-header">pub fn <a href="#method.error" class="fn">error</a>&lt;T: <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/fmt/trait.Display.html" title="trait core::fmt::Display">Display</a>&gt;(&amp;self, message: T) -&gt; <a class="struct" href="struct.Error.html" title="struct syn::parse::Error">Error</a></h4></section></summary><div class="docblock"><p>Triggers an error at the current position of the parse stream.</p>
<h5 id="example-7"><a class="doc-anchor" href="#example-7">§</a>Example</h5>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{Expr, <span class="prelude-ty">Result</span>, Token};
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
<span class="comment">// Some kind of loop: `while` or `for` or `loop`.
</span><span class="kw">struct </span>Loop {
expr: Expr,
}
<span class="kw">impl </span>Parse <span class="kw">for </span>Loop {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="kw">if </span>input.peek(<span class="macro">Token!</span>[<span class="kw">while</span>])
|| input.peek(<span class="macro">Token!</span>[<span class="kw">for</span>])
|| input.peek(<span class="macro">Token!</span>[<span class="kw">loop</span>])
{
<span class="prelude-val">Ok</span>(Loop {
expr: input.parse()<span class="question-mark">?</span>,
})
} <span class="kw">else </span>{
<span class="prelude-val">Err</span>(input.error(<span class="string">"expected some kind of loop"</span>))
}
}
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.step" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#1048-1076">source</a><h4 class="code-header">pub fn <a href="#method.step" class="fn">step</a>&lt;F, R&gt;(&amp;self, function: F) -&gt; <a class="type" href="type.Result.html" title="type syn::parse::Result">Result</a>&lt;R&gt;<div class="where">where
F: for&lt;'c&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(<a class="struct" href="struct.StepCursor.html" title="struct syn::parse::StepCursor">StepCursor</a>&lt;'c, 'a&gt;) -&gt; <a class="type" href="type.Result.html" title="type syn::parse::Result">Result</a>&lt;(R, <a class="struct" href="../buffer/struct.Cursor.html" title="struct syn::buffer::Cursor">Cursor</a>&lt;'c&gt;)&gt;,</div></h4></section></summary><div class="docblock"><p>Speculatively parses tokens from this parse stream, advancing the
position of this stream only if parsing succeeds.</p>
<p>This is a powerful low-level API used for defining the <code>Parse</code> impls of
the basic built-in token types. It is not something that will be used
widely outside of the Syn codebase.</p>
<h5 id="example-8"><a class="doc-anchor" href="#example-8">§</a>Example</h5>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>proc_macro2::TokenTree;
<span class="kw">use </span>syn::Result;
<span class="kw">use </span>syn::parse::ParseStream;
<span class="comment">// This function advances the stream past the next occurrence of `@`. If
// no `@` is present in the stream, the stream position is unchanged and
// an error is returned.
</span><span class="kw">fn </span>skip_past_next_at(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;()&gt; {
input.step(|cursor| {
<span class="kw">let </span><span class="kw-2">mut </span>rest = <span class="kw-2">*</span>cursor;
<span class="kw">while let </span><span class="prelude-val">Some</span>((tt, next)) = rest.token_tree() {
<span class="kw">match </span><span class="kw-2">&amp;</span>tt {
TokenTree::Punct(punct) <span class="kw">if </span>punct.as_char() == <span class="string">'@' </span>=&gt; {
<span class="kw">return </span><span class="prelude-val">Ok</span>(((), next));
}
<span class="kw">_ </span>=&gt; rest = next,
}
}
<span class="prelude-val">Err</span>(cursor.error(<span class="string">"no `@` was found after this point"</span>))
})
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.span" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#1081-1088">source</a><h4 class="code-header">pub fn <a href="#method.span" class="fn">span</a>(&amp;self) -&gt; <a class="struct" href="../../proc_macro2/struct.Span.html" title="struct proc_macro2::Span">Span</a></h4></section></summary><div class="docblock"><p>Returns the <code>Span</code> of the next token in the parse stream, or
<code>Span::call_site()</code> if this parse stream has completely exhausted its
input <code>TokenStream</code>.</p>
</div></details><details class="toggle method-toggle" open><summary><section id="method.cursor" class="method"><a class="src rightside" href="../../src/syn/parse.rs.html#1147-1149">source</a><h4 class="code-header">pub fn <a href="#method.cursor" class="fn">cursor</a>(&amp;self) -&gt; <a class="struct" href="../buffer/struct.Cursor.html" title="struct syn::buffer::Cursor">Cursor</a>&lt;'a&gt;</h4></section></summary><div class="docblock"><p>Provides low-level access to the token representation underlying this
parse stream.</p>
<p>Cursors are immutable so no operations you perform against the cursor
will affect the state of this parse stream.</p>
<h5 id="example-9"><a class="doc-anchor" href="#example-9">§</a>Example</h5>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>proc_macro2::TokenStream;
<span class="kw">use </span>syn::buffer::Cursor;
<span class="kw">use </span>syn::parse::{ParseStream, <span class="prelude-ty">Result</span>};
<span class="comment">// Run a parser that returns T, but get its output as TokenStream instead of T.
// This works without T needing to implement ToTokens.
</span><span class="kw">fn </span>recognize_token_stream&lt;T&gt;(
recognizer: <span class="kw">fn</span>(ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;T&gt;,
) -&gt; <span class="kw">impl </span>Fn(ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;TokenStream&gt; {
<span class="kw">move </span>|input| {
<span class="kw">let </span>begin = input.cursor();
recognizer(input)<span class="question-mark">?</span>;
<span class="kw">let </span>end = input.cursor();
<span class="prelude-val">Ok</span>(tokens_between(begin, end))
}
}
<span class="comment">// Collect tokens between two cursors as a TokenStream.
</span><span class="kw">fn </span>tokens_between(begin: Cursor, end: Cursor) -&gt; TokenStream {
<span class="macro">assert!</span>(begin &lt;= end);
<span class="kw">let </span><span class="kw-2">mut </span>cursor = begin;
<span class="kw">let </span><span class="kw-2">mut </span>tokens = TokenStream::new();
<span class="kw">while </span>cursor &lt; end {
<span class="kw">let </span>(token, next) = cursor.token_tree().unwrap();
tokens.extend(std::iter::once(token));
cursor = next;
}
tokens
}
<span class="kw">fn </span>main() {
<span class="kw">use </span>quote::quote;
<span class="kw">use </span>syn::parse::{Parse, Parser};
<span class="kw">use </span>syn::Token;
<span class="comment">// Parse syn::Type as a TokenStream, surrounded by angle brackets.
</span><span class="kw">fn </span>example(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;TokenStream&gt; {
<span class="kw">let </span>_langle: <span class="macro">Token!</span>[&lt;] = input.parse()<span class="question-mark">?</span>;
<span class="kw">let </span>ty = recognize_token_stream(syn::Type::parse)(input)<span class="question-mark">?</span>;
<span class="kw">let </span>_rangle: <span class="macro">Token!</span>[&gt;] = input.parse()<span class="question-mark">?</span>;
<span class="prelude-val">Ok</span>(ty)
}
<span class="kw">let </span>tokens = <span class="macro">quote!</span> { &lt;<span class="kw">fn</span>() -&gt; u8&gt; };
<span class="macro">println!</span>(<span class="string">"{}"</span>, example.parse2(tokens).unwrap());
}</code></pre></div>
</div></details></div></details></div><h2 id="trait-implementations" class="section-header">Trait Implementations<a href="#trait-implementations" class="anchor">§</a></h2><div id="trait-implementations-list"><details class="toggle implementors-toggle" open><summary><section id="impl-AnyDelimiter-for-ParseBuffer%3C'a%3E" class="impl"><a class="src rightside" href="../../src/syn/discouraged.rs.html#211-225">source</a><a href="#impl-AnyDelimiter-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; <a class="trait" href="discouraged/trait.AnyDelimiter.html" title="trait syn::parse::discouraged::AnyDelimiter">AnyDelimiter</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.parse_any_delimiter" class="method trait-impl"><a class="src rightside" href="../../src/syn/discouraged.rs.html#212-224">source</a><a href="#method.parse_any_delimiter" class="anchor">§</a><h4 class="code-header">fn <a href="discouraged/trait.AnyDelimiter.html#tymethod.parse_any_delimiter" class="fn">parse_any_delimiter</a>(&amp;self) -&gt; <a class="type" href="type.Result.html" title="type syn::parse::Result">Result</a>&lt;(<a class="enum" href="../../proc_macro2/enum.Delimiter.html" title="enum proc_macro2::Delimiter">Delimiter</a>, <a class="struct" href="../../proc_macro2/extra/struct.DelimSpan.html" title="struct proc_macro2::extra::DelimSpan">DelimSpan</a>, <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'_&gt;)&gt;</h4></section></summary><div class='docblock'>Returns the delimiter, the span of the delimiter token, and the nested
contents for further parsing.</div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-Debug-for-ParseBuffer%3C'a%3E" class="impl"><a class="src rightside" href="../../src/syn/parse.rs.html#281-285">source</a><a href="#impl-Debug-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.fmt" class="method trait-impl"><a class="src rightside" href="../../src/syn/parse.rs.html#282-284">source</a><a href="#method.fmt" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/fmt/trait.Debug.html#tymethod.fmt" class="fn">fmt</a>(&amp;self, f: &amp;mut <a class="struct" href="https://doc.rust-lang.org/1.80.0/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>&lt;'_&gt;) -&gt; <a class="type" href="https://doc.rust-lang.org/1.80.0/core/fmt/type.Result.html" title="type core::fmt::Result">Result</a></h4></section></summary><div class='docblock'>Formats the value using the given formatter. <a href="https://doc.rust-lang.org/1.80.0/core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-Display-for-ParseBuffer%3C'a%3E" class="impl"><a class="src rightside" href="../../src/syn/parse.rs.html#275-279">source</a><a href="#impl-Display-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/fmt/trait.Display.html" title="trait core::fmt::Display">Display</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.fmt-1" class="method trait-impl"><a class="src rightside" href="../../src/syn/parse.rs.html#276-278">source</a><a href="#method.fmt-1" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/fmt/trait.Display.html#tymethod.fmt" class="fn">fmt</a>(&amp;self, f: &amp;mut <a class="struct" href="https://doc.rust-lang.org/1.80.0/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>&lt;'_&gt;) -&gt; <a class="type" href="https://doc.rust-lang.org/1.80.0/core/fmt/type.Result.html" title="type core::fmt::Result">Result</a></h4></section></summary><div class='docblock'>Formats the value using the given formatter. <a href="https://doc.rust-lang.org/1.80.0/core/fmt/trait.Display.html#tymethod.fmt">Read more</a></div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-Drop-for-ParseBuffer%3C'a%3E" class="impl"><a class="src rightside" href="../../src/syn/parse.rs.html#264-273">source</a><a href="#impl-Drop-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/ops/drop/trait.Drop.html" title="trait core::ops::drop::Drop">Drop</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.drop" class="method trait-impl"><a class="src rightside" href="../../src/syn/parse.rs.html#265-272">source</a><a href="#method.drop" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/ops/drop/trait.Drop.html#tymethod.drop" class="fn">drop</a>(&amp;mut self)</h4></section></summary><div class='docblock'>Executes the destructor for this type. <a href="https://doc.rust-lang.org/1.80.0/core/ops/drop/trait.Drop.html#tymethod.drop">Read more</a></div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-Speculative-for-ParseBuffer%3C'a%3E" class="impl"><a class="src rightside" href="../../src/syn/discouraged.rs.html#167-201">source</a><a href="#impl-Speculative-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; <a class="trait" href="discouraged/trait.Speculative.html" title="trait syn::parse::discouraged::Speculative">Speculative</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.advance_to" class="method trait-impl"><a class="src rightside" href="../../src/syn/discouraged.rs.html#168-200">source</a><a href="#method.advance_to" class="anchor">§</a><h4 class="code-header">fn <a href="discouraged/trait.Speculative.html#tymethod.advance_to" class="fn">advance_to</a>(&amp;self, fork: <a class="primitive" href="https://doc.rust-lang.org/1.80.0/std/primitive.reference.html">&amp;Self</a>)</h4></section></summary><div class='docblock'>Advance this parse stream to the position of a forked parse stream. <a href="discouraged/trait.Speculative.html#tymethod.advance_to">Read more</a></div></details></div></details><section id="impl-RefUnwindSafe-for-ParseBuffer%3C'a%3E" class="impl"><a class="src rightside" href="../../src/syn/parse.rs.html#288">source</a><a href="#impl-RefUnwindSafe-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/panic/unwind_safe/trait.RefUnwindSafe.html" title="trait core::panic::unwind_safe::RefUnwindSafe">RefUnwindSafe</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section><section id="impl-UnwindSafe-for-ParseBuffer%3C'a%3E" class="impl"><a class="src rightside" href="../../src/syn/parse.rs.html#287">source</a><a href="#impl-UnwindSafe-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/panic/unwind_safe/trait.UnwindSafe.html" title="trait core::panic::unwind_safe::UnwindSafe">UnwindSafe</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section></div><h2 id="synthetic-implementations" class="section-header">Auto Trait Implementations<a href="#synthetic-implementations" class="anchor">§</a></h2><div id="synthetic-implementations-list"><section id="impl-Freeze-for-ParseBuffer%3C'a%3E" class="impl"><a href="#impl-Freeze-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; !<a class="trait" href="https://doc.rust-lang.org/1.80.0/core/marker/trait.Freeze.html" title="trait core::marker::Freeze">Freeze</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section><section id="impl-Send-for-ParseBuffer%3C'a%3E" class="impl"><a href="#impl-Send-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; !<a class="trait" href="https://doc.rust-lang.org/1.80.0/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section><section id="impl-Sync-for-ParseBuffer%3C'a%3E" class="impl"><a href="#impl-Sync-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; !<a class="trait" href="https://doc.rust-lang.org/1.80.0/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section><section id="impl-Unpin-for-ParseBuffer%3C'a%3E" class="impl"><a href="#impl-Unpin-for-ParseBuffer%3C'a%3E" class="anchor">§</a><h3 class="code-header">impl&lt;'a&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/marker/trait.Unpin.html" title="trait core::marker::Unpin">Unpin</a> for <a class="struct" href="struct.ParseBuffer.html" title="struct syn::parse::ParseBuffer">ParseBuffer</a>&lt;'a&gt;</h3></section></div><h2 id="blanket-implementations" class="section-header">Blanket Implementations<a href="#blanket-implementations" class="anchor">§</a></h2><div id="blanket-implementations-list"><details class="toggle implementors-toggle"><summary><section id="impl-Any-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/any.rs.html#140">source</a><a href="#impl-Any-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/any/trait.Any.html" title="trait core::any::Any">Any</a> for T<div class="where">where
T: 'static + ?<a class="trait" href="https://doc.rust-lang.org/1.80.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.type_id" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/any.rs.html#141">source</a><a href="#method.type_id" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/any/trait.Any.html#tymethod.type_id" class="fn">type_id</a>(&amp;self) -&gt; <a class="struct" href="https://doc.rust-lang.org/1.80.0/core/any/struct.TypeId.html" title="struct core::any::TypeId">TypeId</a></h4></section></summary><div class='docblock'>Gets the <code>TypeId</code> of <code>self</code>. <a href="https://doc.rust-lang.org/1.80.0/core/any/trait.Any.html#tymethod.type_id">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-Borrow%3CT%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/borrow.rs.html#208">source</a><a href="#impl-Borrow%3CT%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/borrow/trait.Borrow.html" title="trait core::borrow::Borrow">Borrow</a>&lt;T&gt; for T<div class="where">where
T: ?<a class="trait" href="https://doc.rust-lang.org/1.80.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.borrow" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/borrow.rs.html#210">source</a><a href="#method.borrow" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/borrow/trait.Borrow.html#tymethod.borrow" class="fn">borrow</a>(&amp;self) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.80.0/std/primitive.reference.html">&amp;T</a></h4></section></summary><div class='docblock'>Immutably borrows from an owned value. <a href="https://doc.rust-lang.org/1.80.0/core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-BorrowMut%3CT%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/borrow.rs.html#216">source</a><a href="#impl-BorrowMut%3CT%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/borrow/trait.BorrowMut.html" title="trait core::borrow::BorrowMut">BorrowMut</a>&lt;T&gt; for T<div class="where">where
T: ?<a class="trait" href="https://doc.rust-lang.org/1.80.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.borrow_mut" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/borrow.rs.html#217">source</a><a href="#method.borrow_mut" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut" class="fn">borrow_mut</a>(&amp;mut self) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.80.0/std/primitive.reference.html">&amp;mut T</a></h4></section></summary><div class='docblock'>Mutably borrows from an owned value. <a href="https://doc.rust-lang.org/1.80.0/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-From%3CT%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#765">source</a><a href="#impl-From%3CT%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;T&gt; for T</h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.from" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#768">source</a><a href="#method.from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/convert/trait.From.html#tymethod.from" class="fn">from</a>(t: T) -&gt; T</h4></section></summary><div class="docblock"><p>Returns the argument unchanged.</p>
</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-Into%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#748-750">source</a><a href="#impl-Into%3CU%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T, U&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a>&lt;U&gt; for T<div class="where">where
U: <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;T&gt;,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.into" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#758">source</a><a href="#method.into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/convert/trait.Into.html#tymethod.into" class="fn">into</a>(self) -&gt; U</h4></section></summary><div class="docblock"><p>Calls <code>U::from(self)</code>.</p>
<p>That is, this conversion is whatever the implementation of
<code><a href="https://doc.rust-lang.org/1.80.0/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;T&gt; for U</code> chooses to do.</p>
</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-ToString-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/alloc/string.rs.html#2552">source</a><a href="#impl-ToString-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/alloc/string/trait.ToString.html" title="trait alloc::string::ToString">ToString</a> for T<div class="where">where
T: <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/fmt/trait.Display.html" title="trait core::fmt::Display">Display</a> + ?<a class="trait" href="https://doc.rust-lang.org/1.80.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.to_string" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/alloc/string.rs.html#2558">source</a><a href="#method.to_string" class="anchor">§</a><h4 class="code-header">default fn <a href="https://doc.rust-lang.org/1.80.0/alloc/string/trait.ToString.html#tymethod.to_string" class="fn">to_string</a>(&amp;self) -&gt; <a class="struct" href="https://doc.rust-lang.org/1.80.0/alloc/string/struct.String.html" title="struct alloc::string::String">String</a></h4></section></summary><div class='docblock'>Converts the given value to a <code>String</code>. <a href="https://doc.rust-lang.org/1.80.0/alloc/string/trait.ToString.html#tymethod.to_string">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-TryFrom%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#805-807">source</a><a href="#impl-TryFrom%3CU%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T, U&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;U&gt; for T<div class="where">where
U: <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a>&lt;T&gt;,</div></h3></section></summary><div class="impl-items"><details class="toggle" open><summary><section id="associatedtype.Error" class="associatedtype trait-impl"><a href="#associatedtype.Error" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error" class="associatedtype">Error</a> = <a class="enum" href="https://doc.rust-lang.org/1.80.0/core/convert/enum.Infallible.html" title="enum core::convert::Infallible">Infallible</a></h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="toggle method-toggle" open><summary><section id="method.try_from" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#812">source</a><a href="#method.try_from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#tymethod.try_from" class="fn">try_from</a>(value: U) -&gt; <a class="enum" href="https://doc.rust-lang.org/1.80.0/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;T, &lt;T as <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;U&gt;&gt;::<a class="associatedtype" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>&gt;</h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-TryInto%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#790-792">source</a><a href="#impl-TryInto%3CU%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T, U&gt; <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryInto.html" title="trait core::convert::TryInto">TryInto</a>&lt;U&gt; for T<div class="where">where
U: <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;T&gt;,</div></h3></section></summary><div class="impl-items"><details class="toggle" open><summary><section id="associatedtype.Error-1" class="associatedtype trait-impl"><a href="#associatedtype.Error-1" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryInto.html#associatedtype.Error" class="associatedtype">Error</a> = &lt;U as <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;T&gt;&gt;::<a class="associatedtype" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a></h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="toggle method-toggle" open><summary><section id="method.try_into" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.80.0/src/core/convert/mod.rs.html#797">source</a><a href="#method.try_into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryInto.html#tymethod.try_into" class="fn">try_into</a>(self) -&gt; <a class="enum" href="https://doc.rust-lang.org/1.80.0/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;U, &lt;U as <a class="trait" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;T&gt;&gt;::<a class="associatedtype" href="https://doc.rust-lang.org/1.80.0/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>&gt;</h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details></div></section></div></main></body></html>
Reference in a new issue View git blame Copy permalink