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Trac3r-rust/doc/syn/macro.input_end.html

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<!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="API documentation for the Rust `input_end` macro in crate `syn`."><meta name="keywords" content="rust, rustlang, rust-lang, input_end"><title>syn::input_end - 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="../dark.css"><link rel="stylesheet" type="text/css" href="../light.css" id="themeStyle"><script src="../storage.js"></script><noscript><link rel="stylesheet" href="../noscript.css"></noscript><link rel="shortcut icon" href="../favicon.ico"><style type="text/css">#crate-search{background-image:url("../down-arrow.svg");}</style></head><body class="rustdoc macro"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">&#9776;</div><a href='../syn/index.html'><div class='logo-container'><img src='../rust-logo.png' alt='logo'></div></a><div class="sidebar-elems"><p class='location'><a href='index.html'>syn</a></p><script>window.sidebarCurrent = {name: 'input_end', ty: 'macro', relpath: ''};</script><script defer src="sidebar-items.js"></script></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press S to search, ? for more options…" type="search"></div><a id="settings-menu" href="../settings.html"><img src="../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class='fqn'><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'>&#x2212;</span>]</a></span><a class='srclink' href='../src/syn/parsers.rs.html#1066-1070' title='goto source code'>[src]</a></span><span class='in-band'>Macro <a href='index.html'>syn</a>::<wbr><a class="macro" href=''>input_end</a></span></h1><div class="docblock type-decl hidden-by-usual-hider"><div class="example-wrap"><pre class="rust macro">
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">input_end</span> {
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">expr</span>,) <span class="op">=</span><span class="op">&gt;</span> { ... };
}</pre></div>
</div><div class='docblock'><p>Parse nothing and succeed only if the end of the enclosing block has been
reached.</p>
<p>The enclosing block may be the full input if we are parsing at the top
level, or the surrounding parenthesis/bracket/brace if we are parsing within
those.</p>
<ul>
<li><strong>Syntax:</strong> <code>input_end!()</code></li>
<li><strong>Output:</strong> <code>()</code></li>
</ul>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">macro_use</span>]</span>
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">syn</span>;
<span class="kw">use</span> <span class="ident">syn</span>::<span class="ident">Expr</span>;
<span class="kw">use</span> <span class="ident">syn</span>::<span class="ident">synom</span>::<span class="ident">Synom</span>;
<span class="doccomment">/// Parses any Rust expression followed either by a semicolon or by the end</span>
<span class="doccomment">/// of the input.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// For example `many0!(syn!(TerminatedExpr))` would successfully parse the</span>
<span class="doccomment">/// following input into three expressions.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// 1 + 1; second.two(); third!()</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Similarly within a block, `braced!(many0!(syn!(TerminatedExpr)))` would</span>
<span class="doccomment">/// successfully parse three expressions.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// { 1 + 1; second.two(); third!() }</span>
<span class="kw">struct</span> <span class="ident">TerminatedExpr</span> {
<span class="ident">expr</span>: <span class="ident">Expr</span>,
<span class="ident">semi_token</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="macro">Token</span><span class="macro">!</span>[;]<span class="op">&gt;</span>,
}
<span class="kw">impl</span> <span class="ident">Synom</span> <span class="kw">for</span> <span class="ident">TerminatedExpr</span> {
<span class="macro">named</span><span class="macro">!</span>(<span class="ident">parse</span> <span class="op">-</span><span class="op">&gt;</span> <span class="self">Self</span>, <span class="macro">do_parse</span><span class="macro">!</span>(
<span class="ident">expr</span>: <span class="macro">syn</span><span class="macro">!</span>(<span class="ident">Expr</span>) <span class="op">&gt;</span><span class="op">&gt;</span>
<span class="ident">semi_token</span>: <span class="macro">alt</span><span class="macro">!</span>(
<span class="macro">input_end</span><span class="macro">!</span>() <span class="op">=</span><span class="op">&gt;</span> { <span class="op">|</span><span class="kw">_</span><span class="op">|</span> <span class="prelude-val">None</span> }
<span class="op">|</span>
<span class="macro">punct</span><span class="macro">!</span>(;) <span class="op">=</span><span class="op">&gt;</span> { <span class="prelude-val">Some</span> }
) <span class="op">&gt;</span><span class="op">&gt;</span>
(<span class="ident">TerminatedExpr</span> {
<span class="ident">expr</span>,
<span class="ident">semi_token</span>,
})
));
}</pre></div>
<p><em>This macro is available if Syn is built with the <code>&quot;parsing&quot;</code> feature.</em></p>
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