mentat/docs/apis/rust/syn/struct.Attribute.html
2018-06-22 12:08:32 +01:00

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<p class='location'>Struct Attribute</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#fields">Fields</a><div class="sidebar-links"><a href="#structfield.pound_token">pound_token</a><a href="#structfield.style">style</a><a href="#structfield.bracket_token">bracket_token</a><a href="#structfield.path">path</a><a href="#structfield.tts">tts</a><a href="#structfield.is_sugared_doc">is_sugared_doc</a></div><a class="sidebar-title" href="#methods">Methods</a><div class="sidebar-links"><a href="#method.parse_inner">parse_inner</a><a href="#method.parse_outer">parse_outer</a><a href="#method.interpret_meta">interpret_meta</a></div><a class="sidebar-title" href="#implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-ToTokens">ToTokens</a><a href="#impl-Clone">Clone</a></div><a class="sidebar-title" href="#synthetic-implementations">Auto Trait Implementations</a><div class="sidebar-links"><a href="#impl-Send">!Send</a><a href="#impl-Sync">!Sync</a></div></div><p class='location'><a href='index.html'>syn</a></p><script>window.sidebarCurrent = {name: 'Attribute', ty: 'struct', relpath: ''};</script><script defer src="sidebar-items.js"></script></div>
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<section id='main' class="content"><h1 class='fqn'><span class='in-band'>Struct <a href='index.html'>syn</a>::<wbr><a class="struct" href=''>Attribute</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'>&#x2212;</span>]
</a>
</span><a class='srclink' href='../src/syn/macros.rs.html#37' title='goto source code'>[src]</a></span></h1><div class="docblock type-decl"><pre class='rust struct'>pub struct Attribute {
pub pound_token: <a class="struct" href="../syn/token/struct.Pound.html" title="struct syn::token::Pound">Pound</a>,
pub style: <a class="enum" href="../syn/enum.AttrStyle.html" title="enum syn::AttrStyle">AttrStyle</a>,
pub bracket_token: <a class="struct" href="../syn/token/struct.Bracket.html" title="struct syn::token::Bracket">Bracket</a>,
pub path: <a class="struct" href="../syn/struct.Path.html" title="struct syn::Path">Path</a>,
pub tts: <a class="struct" href="../proc_macro2/struct.TokenStream.html" title="struct proc_macro2::TokenStream">TokenStream</a>,
pub is_sugared_doc: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a>,
}</pre></div><div class='docblock'><p>An attribute like <code>#[repr(transparent)]</code>.</p>
<p><em>This type is available if Syn is built with the <code>&quot;derive&quot;</code> or <code>&quot;full&quot;</code>
feature.</em></p>
<h1 id="syntax" class="section-header"><a href="#syntax">Syntax</a></h1>
<p>Rust has six types of attributes.</p>
<ul>
<li>Outer attributes like <code>#[repr(transparent)]</code>. These appear outside or
in front of the item they describe.</li>
<li>Inner attributes like <code>#![feature(proc_macro)]</code>. These appear inside
of the item they describe, usually a module.</li>
<li>Outer doc comments like <code>/// # Example</code>.</li>
<li>Inner doc comments like <code>//! Please file an issue</code>.</li>
<li>Outer block comments <code>/** # Example */</code>.</li>
<li>Inner block comments <code>/*! Please file an issue */</code>.</li>
</ul>
<p>The <code>style</code> field of type <code>AttrStyle</code> distinguishes whether an attribute
is outer or inner. Doc comments and block comments are promoted to
attributes that have <code>is_sugared_doc</code> set to true, as this is how they
are processed by the compiler and by <code>macro_rules!</code> macros.</p>
<p>The <code>path</code> field gives the possibly colon-delimited path against which
the attribute is resolved. It is equal to <code>&quot;doc&quot;</code> for desugared doc
comments. The <code>tts</code> field contains the rest of the attribute body as
tokens.</p>
<pre><code class="language-text">#[derive(Copy)] #[crate::precondition x &lt; 5]
^^^^^^~~~~~~ ^^^^^^^^^^^^^^^^^^^ ~~~~~
path tts path tts
</code></pre>
<p>Use the <a href="#method.interpret_meta"><code>interpret_meta</code></a> method to try parsing the tokens of an
attribute into the structured representation that is used by convention
across most Rust libraries.</p>
</div><h2 id='fields' class='fields small-section-header'>
Fields<a href='#fields' class='anchor'></a></h2><span id="structfield.pound_token" class="structfield small-section-header">
<a href="#structfield.pound_token" class="anchor field"></a>
<span id="pound_token.v" class='invisible'>
<code>pound_token: <a class="struct" href="../syn/token/struct.Pound.html" title="struct syn::token::Pound">Pound</a></code>
</span></span><span id="structfield.style" class="structfield small-section-header">
<a href="#structfield.style" class="anchor field"></a>
<span id="style.v" class='invisible'>
<code>style: <a class="enum" href="../syn/enum.AttrStyle.html" title="enum syn::AttrStyle">AttrStyle</a></code>
</span></span><span id="structfield.bracket_token" class="structfield small-section-header">
<a href="#structfield.bracket_token" class="anchor field"></a>
<span id="bracket_token.v" class='invisible'>
<code>bracket_token: <a class="struct" href="../syn/token/struct.Bracket.html" title="struct syn::token::Bracket">Bracket</a></code>
</span></span><span id="structfield.path" class="structfield small-section-header">
<a href="#structfield.path" class="anchor field"></a>
<span id="path.v" class='invisible'>
<code>path: <a class="struct" href="../syn/struct.Path.html" title="struct syn::Path">Path</a></code>
</span></span><span id="structfield.tts" class="structfield small-section-header">
<a href="#structfield.tts" class="anchor field"></a>
<span id="tts.v" class='invisible'>
<code>tts: <a class="struct" href="../proc_macro2/struct.TokenStream.html" title="struct proc_macro2::TokenStream">TokenStream</a></code>
</span></span><span id="structfield.is_sugared_doc" class="structfield small-section-header">
<a href="#structfield.is_sugared_doc" class="anchor field"></a>
<span id="is_sugared_doc.v" class='invisible'>
<code>is_sugared_doc: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code>
</span></span>
<h2 id='methods' class='small-section-header'>
Methods<a href='#methods' class='anchor'></a>
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<h3 id='impl' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="struct" href="../syn/struct.Attribute.html" title="struct syn::Attribute">Attribute</a></code><a href='#impl' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/syn/attr.rs.html#410-491' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.parse_inner' class="method"><span id='parse_inner.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.parse_inner' class='fnname'>parse_inner</a>(i: <a class="struct" href="../syn/buffer/struct.Cursor.html" title="struct syn::buffer::Cursor">Cursor</a>) -&gt; <a class="type" href="../syn/synom/type.PResult.html" title="type syn::synom::PResult">PResult</a>&lt;Self&gt;</code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/syn/parsers.rs.html#74-76' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><h4 id='method.parse_outer' class="method"><span id='parse_outer.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.parse_outer' class='fnname'>parse_outer</a>(i: <a class="struct" href="../syn/buffer/struct.Cursor.html" title="struct syn::buffer::Cursor">Cursor</a>) -&gt; <a class="type" href="../syn/synom/type.PResult.html" title="type syn::synom::PResult">PResult</a>&lt;Self&gt;</code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/syn/parsers.rs.html#74-76' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4></div><h3 id='impl-1' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="struct" href="../syn/struct.Attribute.html" title="struct syn::Attribute">Attribute</a></code><a href='#impl-1' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/syn/attr.rs.html#101-186' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.interpret_meta' class="method"><span id='interpret_meta.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.interpret_meta' class='fnname'>interpret_meta</a>(&amp;self) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="enum" href="../syn/enum.Meta.html" title="enum syn::Meta">Meta</a>&gt;</code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/syn/attr.rs.html#104-130' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Parses the tokens after the path as a <a href="enum.Meta.html"><code>Meta</code></a> if
possible.</p>
</div></div>
<h2 id='implementations' class='small-section-header'>
Trait Implementations<a href='#implementations' class='anchor'></a>
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<h3 id='impl-ToTokens' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="trait" href="../quote/to_tokens/trait.ToTokens.html" title="trait quote::to_tokens::ToTokens">ToTokens</a> for <a class="struct" href="../syn/struct.Attribute.html" title="struct syn::Attribute">Attribute</a></code><a href='#impl-ToTokens' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/syn/attr.rs.html#525-536' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.to_tokens' class="method"><span id='to_tokens.v' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='../quote/to_tokens/trait.ToTokens.html#tymethod.to_tokens' class='fnname'>to_tokens</a>(&amp;self, tokens: &amp;mut <a class="struct" href="../proc_macro2/struct.TokenStream.html" title="struct proc_macro2::TokenStream">TokenStream</a>)</code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/syn/attr.rs.html#526-535' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Write <code>self</code> to the given <code>TokenStream</code>. <a href="../quote/to_tokens/trait.ToTokens.html#tymethod.to_tokens">Read more</a></p>
</div><h4 id='method.into_token_stream' class="method"><span id='into_token_stream.v' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='../quote/to_tokens/trait.ToTokens.html#method.into_token_stream' class='fnname'>into_token_stream</a>(self) -&gt; <a class="struct" href="../proc_macro2/struct.TokenStream.html" title="struct proc_macro2::TokenStream">TokenStream</a></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/quote/to_tokens.rs.html#64-71' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Convert <code>self</code> directly into a <code>TokenStream</code> object. <a href="../quote/to_tokens/trait.ToTokens.html#method.into_token_stream">Read more</a></p>
</div></div><h3 id='impl-Clone' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a> for <a class="struct" href="../syn/struct.Attribute.html" title="struct syn::Attribute">Attribute</a></code><a href='#impl-Clone' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/syn/macros.rs.html#36' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.clone' class="method"><span id='clone.v' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#tymethod.clone' class='fnname'>clone</a>(&amp;self) -&gt; <a class="struct" href="../syn/struct.Attribute.html" title="struct syn::Attribute">Attribute</a></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../src/syn/macros.rs.html#36' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Returns a copy of the value. <a href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#tymethod.clone">Read more</a></p>
</div><h4 id='method.clone_from' class="method"><span id='clone_from.v' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#method.clone_from' class='fnname'>clone_from</a>(&amp;mut self, source: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;</a>Self)</code></span></td><td><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.0.0'>1.0.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/clone.rs.html#117-119' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Performs copy-assignment from <code>source</code>. <a href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#method.clone_from">Read more</a></p>
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Auto Trait Implementations<a href='#synthetic-implementations' class='anchor'></a>
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<h3 id='impl-Send' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl !<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="../syn/struct.Attribute.html" title="struct syn::Attribute">Attribute</a></code><a href='#impl-Send' class='anchor'></a></span></td><td><span class='out-of-band'></span></td></tr></tbody></table></h3><div class='impl-items'></div><h3 id='impl-Sync' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl !<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="../syn/struct.Attribute.html" title="struct syn::Attribute">Attribute</a></code><a href='#impl-Sync' class='anchor'></a></span></td><td><span class='out-of-band'></span></td></tr></tbody></table></h3><div class='impl-items'></div></div></section>
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