185 lines
No EOL
9 KiB
HTML
185 lines
No EOL
9 KiB
HTML
<!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 `quote` macro in crate `quote`.">
|
||
<meta name="keywords" content="rust, rustlang, rust-lang, quote">
|
||
|
||
<title>quote::quote - 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="../main.css" id="themeStyle">
|
||
<script src="../storage.js"></script>
|
||
|
||
|
||
|
||
|
||
</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">☰</div>
|
||
|
||
<p class='location'><a href='index.html'>quote</a></p><script>window.sidebarCurrent = {name: 'quote', ty: 'macro', relpath: ''};</script><script defer src="sidebar-items.js"></script>
|
||
</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">
|
||
<input class="search-input" name="search"
|
||
autocomplete="off"
|
||
placeholder="Click or press ‘S’ to search, ‘?’ for more options…"
|
||
type="search">
|
||
</div>
|
||
</form>
|
||
</nav>
|
||
|
||
<section id='main' class="content">
|
||
<h1 class='fqn'><span class='in-band'>Macro <a href='index.html'>quote</a>::<wbr><a class="macro" href=''>quote</a></span><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'>−</span>]
|
||
</a>
|
||
</span><a class='srclink' href='../src/quote/lib.rs.html#321-323' 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">quote</span> {
|
||
($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">tt</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> { ... };
|
||
}</pre>
|
||
<div class='docblock'><p>The whole point.</p>
|
||
<p>Performs variable interpolation against the input and produces it as
|
||
<a href="https://docs.rs/proc-macro2/0.4/proc_macro2/struct.TokenStream.html"><code>TokenStream</code></a>. For returning tokens to the compiler in a procedural macro, use
|
||
<code>into()</code> to build a <code>TokenStream</code>.</p>
|
||
<h1 id="interpolation" class="section-header"><a href="#interpolation">Interpolation</a></h1>
|
||
<p>Variable interpolation is done with <code>#var</code> (similar to <code>$var</code> in
|
||
<code>macro_rules!</code> macros). This grabs the <code>var</code> variable that is currently in
|
||
scope and inserts it in that location in the output tokens. Any type
|
||
implementing the <a href="trait.ToTokens.html"><code>ToTokens</code></a> trait can be interpolated. This includes most
|
||
Rust primitive types as well as most of the syntax tree types from the <a href="https://github.com/dtolnay/syn">Syn</a>
|
||
crate.</p>
|
||
<p>Repetition is done using <code>#(...)*</code> or <code>#(...),*</code> again similar to
|
||
<code>macro_rules!</code>. This iterates through the elements of any variable
|
||
interpolated within the repetition and inserts a copy of the repetition body
|
||
for each one. The variables in an interpolation may be anything that
|
||
implements <code>IntoIterator</code>, including <code>Vec</code> or a pre-existing iterator.</p>
|
||
<ul>
|
||
<li><code>#(#var)*</code> — no separators</li>
|
||
<li><code>#(#var),*</code> — the character before the asterisk is used as a separator</li>
|
||
<li><code>#( struct #var; )*</code> — the repetition can contain other tokens</li>
|
||
<li><code>#( #k => println!("{}", #v), )*</code> — even multiple interpolations</li>
|
||
</ul>
|
||
<h1 id="hygiene" class="section-header"><a href="#hygiene">Hygiene</a></h1>
|
||
<p>Any interpolated tokens preserve the <code>Span</code> information provided by their
|
||
<code>ToTokens</code> implementation. Tokens that originate within the <code>quote!</code>
|
||
invocation are spanned with <a href="https://docs.rs/proc-macro2/0.4/proc_macro2/struct.Span.html#method.call_site"><code>Span::call_site()</code></a>.</p>
|
||
<p>A different span can be provided through the <a href="macro.quote_spanned.html"><code>quote_spanned!</code></a> macro.</p>
|
||
<h1 id="example" class="section-header"><a href="#example">Example</a></h1>
|
||
<pre class="rust rust-example-rendered">
|
||
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">proc_macro</span>;
|
||
|
||
<span class="attribute">#[<span class="ident">macro_use</span>]</span>
|
||
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">quote</span>;
|
||
|
||
<span class="kw">use</span> <span class="ident">proc_macro</span>::<span class="ident">TokenStream</span>;
|
||
|
||
<span class="attribute">#[<span class="ident">proc_macro_derive</span>(<span class="ident">HeapSize</span>)]</span>
|
||
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">derive_heap_size</span>(<span class="ident">input</span>: <span class="ident">TokenStream</span>) <span class="op">-></span> <span class="ident">TokenStream</span> {
|
||
<span class="comment">// Parse the input and figure out what implementation to generate...</span>
|
||
<span class="kw">let</span> <span class="ident">name</span> <span class="op">=</span> <span class="comment">/* ... */</span>;
|
||
<span class="kw">let</span> <span class="ident">expr</span> <span class="op">=</span> <span class="comment">/* ... */</span>;
|
||
|
||
<span class="kw">let</span> <span class="ident">expanded</span> <span class="op">=</span> <span class="macro">quote</span><span class="macro">!</span> {
|
||
<span class="comment">// The generated impl.</span>
|
||
<span class="kw">impl</span> ::<span class="ident">heapsize</span>::<span class="ident">HeapSize</span> <span class="kw">for</span> #<span class="ident">name</span> {
|
||
<span class="kw">fn</span> <span class="ident">heap_size_of_children</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">usize</span> {
|
||
#<span class="ident">expr</span>
|
||
}
|
||
}
|
||
};
|
||
|
||
<span class="comment">// Hand the output tokens back to the compiler.</span>
|
||
<span class="ident">expanded</span>.<span class="ident">into</span>()
|
||
}</pre>
|
||
</div></section>
|
||
<section id='search' class="content hidden"></section>
|
||
|
||
<section class="footer"></section>
|
||
|
||
<aside id="help" class="hidden">
|
||
<div>
|
||
<h1 class="hidden">Help</h1>
|
||
|
||
<div class="shortcuts">
|
||
<h2>Keyboard Shortcuts</h2>
|
||
|
||
<dl>
|
||
<dt><kbd>?</kbd></dt>
|
||
<dd>Show this help dialog</dd>
|
||
<dt><kbd>S</kbd></dt>
|
||
<dd>Focus the search field</dd>
|
||
<dt><kbd>↑</kbd></dt>
|
||
<dd>Move up in search results</dd>
|
||
<dt><kbd>↓</kbd></dt>
|
||
<dd>Move down in search results</dd>
|
||
<dt><kbd>↹</kbd></dt>
|
||
<dd>Switch tab</dd>
|
||
<dt><kbd>⏎</kbd></dt>
|
||
<dd>Go to active search result</dd>
|
||
<dt><kbd>+</kbd></dt>
|
||
<dd>Expand all sections</dd>
|
||
<dt><kbd>-</kbd></dt>
|
||
<dd>Collapse all sections</dd>
|
||
</dl>
|
||
</div>
|
||
|
||
<div class="infos">
|
||
<h2>Search Tricks</h2>
|
||
|
||
<p>
|
||
Prefix searches with a type followed by a colon (e.g.
|
||
<code>fn:</code>) to restrict the search to a given type.
|
||
</p>
|
||
|
||
<p>
|
||
Accepted types are: <code>fn</code>, <code>mod</code>,
|
||
<code>struct</code>, <code>enum</code>,
|
||
<code>trait</code>, <code>type</code>, <code>macro</code>,
|
||
and <code>const</code>.
|
||
</p>
|
||
|
||
<p>
|
||
Search functions by type signature (e.g.
|
||
<code>vec -> usize</code> or <code>* -> vec</code>)
|
||
</p>
|
||
</div>
|
||
</div>
|
||
</aside>
|
||
|
||
|
||
|
||
<script>
|
||
window.rootPath = "../";
|
||
window.currentCrate = "quote";
|
||
</script>
|
||
<script src="../main.js"></script>
|
||
<script defer src="../search-index.js"></script>
|
||
</body>
|
||
</html> |