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<h1 class='fqn'><span class='in-band'>Macro <a href='index.html'>syn</a>::<wbr><a class="macro" href=''>do_parse</a></span><span class='out-of-band'><span id='render-detail'>
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[<span class='inner'>&#x2212;</span>]
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</span><a class='srclink' href='../src/syn/parsers.rs.html#955-1002' title='goto source code'>[src]</a></span></h1>
<pre class="rust macro">
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">do_parse</span> {
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">expr</span>, ( $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">expr</span>),<span class="op">*</span> )) <span class="op">=&gt;</span> { ... };
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">expr</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">e</span>:<span class="ident">ident</span> <span class="op">&gt;&gt;</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=&gt;</span> { ... };
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">expr</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">submac</span>:<span class="macro">ident</span><span class="macro">!</span>( $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">args</span>:<span class="ident">tt</span>)<span class="op">*</span> ) <span class="op">&gt;&gt;</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=&gt;</span> { ... };
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">expr</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">field</span>:<span class="ident">ident</span> : <span class="macro-nonterminal">$</span><span class="macro-nonterminal">e</span>:<span class="ident">ident</span> <span class="op">&gt;&gt;</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=&gt;</span> { ... };
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">expr</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">field</span>:<span class="ident">ident</span> : <span class="macro-nonterminal">$</span><span class="macro-nonterminal">submac</span>:<span class="macro">ident</span><span class="macro">!</span>( $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">args</span>:<span class="ident">tt</span>)<span class="op">*</span> ) <span class="op">&gt;&gt;</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=&gt;</span> { ... };
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">expr</span>, <span class="kw-2">mut</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">field</span>:<span class="ident">ident</span> : <span class="macro-nonterminal">$</span><span class="macro-nonterminal">e</span>:<span class="ident">ident</span> <span class="op">&gt;&gt;</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=&gt;</span> { ... };
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">i</span>:<span class="ident">expr</span>, <span class="kw-2">mut</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">field</span>:<span class="ident">ident</span> : <span class="macro-nonterminal">$</span><span class="macro-nonterminal">submac</span>:<span class="macro">ident</span><span class="macro">!</span>( $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">args</span>:<span class="ident">tt</span>)<span class="op">*</span> ) <span class="op">&gt;&gt;</span> $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=&gt;</span> { ... };
}</pre>
<div class='docblock'><p>Run a series of parsers, optionally naming each intermediate result,
followed by a step to combine the intermediate results.</p>
<p>Produces the result of evaluating the final expression in parentheses with
all of the previously named results bound.</p>
<ul>
<li><strong>Syntax:</strong> <code>do_parse!(name: THING1 &gt;&gt; THING2 &gt;&gt; (RESULT))</code></li>
<li><strong>Output:</strong> <code>RESULT</code></li>
</ul>
<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">extern</span> <span class="kw">crate</span> <span class="ident">proc_macro2</span>;
<span class="kw">use</span> <span class="ident">proc_macro2</span>::<span class="ident">Ident</span>;
<span class="kw">use</span> <span class="ident">proc_macro2</span>::<span class="ident">TokenStream</span>;
<span class="kw">use</span> <span class="ident">syn</span>::<span class="ident">token</span>::<span class="ident">Paren</span>;
<span class="kw">use</span> <span class="ident">syn</span>::<span class="ident">synom</span>::<span class="ident">Synom</span>;
<span class="doccomment">/// Parse a macro invocation that uses `(` `)` parentheses.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Example: `stringify!($args)`.</span>
<span class="kw">struct</span> <span class="ident">Macro</span> {
<span class="ident">name</span>: <span class="ident">Ident</span>,
<span class="ident">bang_token</span>: <span class="macro">Token</span><span class="macro">!</span>[<span class="op">!</span>],
<span class="ident">paren_token</span>: <span class="ident">Paren</span>,
<span class="ident">tts</span>: <span class="ident">TokenStream</span>,
}
<span class="kw">impl</span> <span class="ident">Synom</span> <span class="kw">for</span> <span class="ident">Macro</span> {
<span class="macro">named</span><span class="macro">!</span>(<span class="ident">parse</span> <span class="op">-&gt;</span> <span class="self">Self</span>, <span class="macro">do_parse</span><span class="macro">!</span>(
<span class="ident">name</span>: <span class="macro">syn</span><span class="macro">!</span>(<span class="ident">Ident</span>) <span class="op">&gt;&gt;</span>
<span class="ident">bang_token</span>: <span class="macro">punct</span><span class="macro">!</span>(<span class="op">!</span>) <span class="op">&gt;&gt;</span>
<span class="ident">body</span>: <span class="macro">parens</span><span class="macro">!</span>(<span class="macro">syn</span><span class="macro">!</span>(<span class="ident">TokenStream</span>)) <span class="op">&gt;&gt;</span>
(<span class="ident">Macro</span> {
<span class="ident">name</span>,
<span class="ident">bang_token</span>,
<span class="ident">paren_token</span>: <span class="ident">body</span>.<span class="number">0</span>,
<span class="ident">tts</span>: <span class="ident">body</span>.<span class="number">1</span>,
})
));
}</pre>
<p><em>This macro is available if Syn is built with the <code>&quot;parsing&quot;</code> feature.</em></p>
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