2019-09-06 15:57:44 -07:00

174 lines
22 KiB
HTML
Raw Permalink Blame History

This file contains ambiguous Unicode characters

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="API documentation for the Rust `synstructure` crate."><meta name="keywords" content="rust, rustlang, rust-lang, synstructure"><title>synstructure - 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 mod"><!--[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='../synstructure/index.html'><div class='logo-container'><img src='../rust-logo.png' alt='logo'></div></a><p class='location'>Crate synstructure</p><div class="sidebar-elems"><a id='all-types' href='all.html'><p>See all synstructure's items</p></a><div class="block items"><ul><li><a href="#macros">Macros</a></li><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li><li><a href="#functions">Functions</a></li></ul></div><p class='location'></p><script>window.sidebarCurrent = {name: 'synstructure', ty: 'mod', relpath: '../'};</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/synstructure/lib.rs.html#1-2301' title='goto source code'>[src]</a></span><span class='in-band'>Crate <a class="mod" href=''>synstructure</a></span></h1><div class='docblock'><p>This crate provides helper types for matching against enum variants, and
extracting bindings to each of the fields in the deriving Struct or Enum in
a generic way.</p>
<p>If you are writing a <code>#[derive]</code> which needs to perform some operation on
every field, then you have come to the right place!</p>
<h1 id="example-walkfields" class="section-header"><a href="#example-walkfields">Example: <code>WalkFields</code></a></h1><h3 id="trait-implementation" class="section-header"><a href="#trait-implementation">Trait Implementation</a></h3>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="kw">pub</span> <span class="kw">trait</span> <span class="ident">WalkFields</span>: <span class="ident">std</span>::<span class="ident">any</span>::<span class="ident">Any</span> {
<span class="kw">fn</span> <span class="ident">walk_fields</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">walk</span>: <span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">FnMut</span>(<span class="kw-2">&amp;</span><span class="ident">WalkFields</span>));
}
<span class="kw">impl</span> <span class="ident">WalkFields</span> <span class="kw">for</span> <span class="ident">i32</span> {
<span class="kw">fn</span> <span class="ident">walk_fields</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">_walk</span>: <span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">FnMut</span>(<span class="kw-2">&amp;</span><span class="ident">WalkFields</span>)) {}
}</pre></div>
<h3 id="custom-derive" class="section-header"><a href="#custom-derive">Custom Derive</a></h3>
<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">synstructure</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">extern</span> <span class="kw">crate</span> <span class="ident">proc_macro2</span>;
<span class="kw">fn</span> <span class="ident">walkfields_derive</span>(<span class="ident">s</span>: <span class="ident">synstructure</span>::<span class="ident">Structure</span>) <span class="op">-</span><span class="op">&gt;</span> <span class="ident">proc_macro2</span>::<span class="ident">TokenStream</span> {
<span class="kw">let</span> <span class="ident">body</span> <span class="op">=</span> <span class="ident">s</span>.<span class="ident">each</span>(<span class="op">|</span><span class="ident">bi</span><span class="op">|</span> <span class="macro">quote</span><span class="macro">!</span>{
<span class="ident">walk</span>(#<span class="ident">bi</span>)
});
<span class="ident">s</span>.<span class="ident">gen_impl</span>(<span class="macro">quote</span><span class="macro">!</span> {
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">synstructure_test_traits</span>;
<span class="ident">gen</span> <span class="kw">impl</span> <span class="ident">synstructure_test_traits</span>::<span class="ident">WalkFields</span> <span class="kw">for</span> @<span class="self">Self</span> {
<span class="kw">fn</span> <span class="ident">walk_fields</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">walk</span>: <span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">FnMut</span>(<span class="kw-2">&amp;</span><span class="ident">synstructure_test_traits</span>::<span class="ident">WalkFields</span>)) {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> { #<span class="ident">body</span> }
}
}
})
}
<span class="macro">decl_derive</span><span class="macro">!</span>([<span class="ident">WalkFields</span>] <span class="op">=</span><span class="op">&gt;</span> <span class="ident">walkfields_derive</span>);
<span class="comment">/*
* Test Case
*/</span>
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="macro">test_derive</span><span class="macro">!</span> {
<span class="ident">walkfields_derive</span> {
<span class="kw">enum</span> <span class="ident">A</span><span class="op">&lt;</span><span class="ident">T</span><span class="op">&gt;</span> {
<span class="ident">B</span>(<span class="ident">i32</span>, <span class="ident">T</span>),
<span class="ident">C</span>(<span class="ident">i32</span>),
}
}
<span class="ident">expands</span> <span class="ident">to</span> {
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">non_upper_case_globals</span>)]</span>
<span class="kw">const</span> <span class="ident">_DERIVE_synstructure_test_traits_WalkFields_FOR_A</span>: () <span class="op">=</span> {
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">synstructure_test_traits</span>;
<span class="kw">impl</span><span class="op">&lt;</span><span class="ident">T</span><span class="op">&gt;</span> <span class="ident">synstructure_test_traits</span>::<span class="ident">WalkFields</span> <span class="kw">for</span> <span class="ident">A</span><span class="op">&lt;</span><span class="ident">T</span><span class="op">&gt;</span>
<span class="kw">where</span> <span class="ident">T</span>: <span class="ident">synstructure_test_traits</span>::<span class="ident">WalkFields</span>
{
<span class="kw">fn</span> <span class="ident">walk_fields</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">walk</span>: <span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">FnMut</span>(<span class="kw-2">&amp;</span><span class="ident">synstructure_test_traits</span>::<span class="ident">WalkFields</span>)) {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
<span class="ident">A</span>::<span class="ident">B</span>(<span class="kw-2">ref</span> <span class="ident">__binding_0</span>, <span class="kw-2">ref</span> <span class="ident">__binding_1</span>,) <span class="op">=</span><span class="op">&gt;</span> {
{ <span class="ident">walk</span>(<span class="ident">__binding_0</span>) }
{ <span class="ident">walk</span>(<span class="ident">__binding_1</span>) }
}
<span class="ident">A</span>::<span class="ident">C</span>(<span class="kw-2">ref</span> <span class="ident">__binding_0</span>,) <span class="op">=</span><span class="op">&gt;</span> {
{ <span class="ident">walk</span>(<span class="ident">__binding_0</span>) }
}
}
}
}
};
}
}
}</pre></div>
<h1 id="example-interest" class="section-header"><a href="#example-interest">Example: <code>Interest</code></a></h1><h3 id="trait-implementation-1" class="section-header"><a href="#trait-implementation-1">Trait Implementation</a></h3>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="kw">pub</span> <span class="kw">trait</span> <span class="ident">Interest</span> {
<span class="kw">fn</span> <span class="ident">interesting</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) <span class="op">-</span><span class="op">&gt;</span> <span class="ident">bool</span>;
}
<span class="kw">impl</span> <span class="ident">Interest</span> <span class="kw">for</span> <span class="ident">i32</span> {
<span class="kw">fn</span> <span class="ident">interesting</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) <span class="op">-</span><span class="op">&gt;</span> <span class="ident">bool</span> { <span class="kw-2">*</span><span class="self">self</span> <span class="op">&gt;</span> <span class="number">0</span> }
}</pre></div>
<h3 id="custom-derive-1" class="section-header"><a href="#custom-derive-1">Custom Derive</a></h3>
<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">synstructure</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">extern</span> <span class="kw">crate</span> <span class="ident">proc_macro2</span>;
<span class="kw">fn</span> <span class="ident">interest_derive</span>(<span class="kw-2">mut</span> <span class="ident">s</span>: <span class="ident">synstructure</span>::<span class="ident">Structure</span>) <span class="op">-</span><span class="op">&gt;</span> <span class="ident">proc_macro2</span>::<span class="ident">TokenStream</span> {
<span class="kw">let</span> <span class="ident">body</span> <span class="op">=</span> <span class="ident">s</span>.<span class="ident">fold</span>(<span class="bool-val">false</span>, <span class="op">|</span><span class="ident">acc</span>, <span class="ident">bi</span><span class="op">|</span> <span class="macro">quote</span><span class="macro">!</span>{
#<span class="ident">acc</span> <span class="op">|</span><span class="op">|</span> <span class="ident">synstructure_test_traits</span>::<span class="ident">Interest</span>::<span class="ident">interesting</span>(#<span class="ident">bi</span>)
});
<span class="ident">s</span>.<span class="ident">gen_impl</span>(<span class="macro">quote</span><span class="macro">!</span> {
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">synstructure_test_traits</span>;
<span class="ident">gen</span> <span class="kw">impl</span> <span class="ident">synstructure_test_traits</span>::<span class="ident">Interest</span> <span class="kw">for</span> @<span class="self">Self</span> {
<span class="kw">fn</span> <span class="ident">interesting</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) <span class="op">-</span><span class="op">&gt;</span> <span class="ident">bool</span> {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
#<span class="ident">body</span>
}
}
}
})
}
<span class="macro">decl_derive</span><span class="macro">!</span>([<span class="ident">Interest</span>] <span class="op">=</span><span class="op">&gt;</span> <span class="ident">interest_derive</span>);
<span class="comment">/*
* Test Case
*/</span>
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="macro">test_derive</span><span class="macro">!</span>{
<span class="ident">interest_derive</span> {
<span class="kw">enum</span> <span class="ident">A</span><span class="op">&lt;</span><span class="ident">T</span><span class="op">&gt;</span> {
<span class="ident">B</span>(<span class="ident">i32</span>, <span class="ident">T</span>),
<span class="ident">C</span>(<span class="ident">i32</span>),
}
}
<span class="ident">expands</span> <span class="ident">to</span> {
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">non_upper_case_globals</span>)]</span>
<span class="kw">const</span> <span class="ident">_DERIVE_synstructure_test_traits_Interest_FOR_A</span>: () <span class="op">=</span> {
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">synstructure_test_traits</span>;
<span class="kw">impl</span><span class="op">&lt;</span><span class="ident">T</span><span class="op">&gt;</span> <span class="ident">synstructure_test_traits</span>::<span class="ident">Interest</span> <span class="kw">for</span> <span class="ident">A</span><span class="op">&lt;</span><span class="ident">T</span><span class="op">&gt;</span>
<span class="kw">where</span> <span class="ident">T</span>: <span class="ident">synstructure_test_traits</span>::<span class="ident">Interest</span>
{
<span class="kw">fn</span> <span class="ident">interesting</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) <span class="op">-</span><span class="op">&gt;</span> <span class="ident">bool</span> {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
<span class="ident">A</span>::<span class="ident">B</span>(<span class="kw-2">ref</span> <span class="ident">__binding_0</span>, <span class="kw-2">ref</span> <span class="ident">__binding_1</span>,) <span class="op">=</span><span class="op">&gt;</span> {
<span class="bool-val">false</span> <span class="op">|</span><span class="op">|</span>
<span class="ident">synstructure_test_traits</span>::<span class="ident">Interest</span>::<span class="ident">interesting</span>(<span class="ident">__binding_0</span>) <span class="op">|</span><span class="op">|</span>
<span class="ident">synstructure_test_traits</span>::<span class="ident">Interest</span>::<span class="ident">interesting</span>(<span class="ident">__binding_1</span>)
}
<span class="ident">A</span>::<span class="ident">C</span>(<span class="kw-2">ref</span> <span class="ident">__binding_0</span>,) <span class="op">=</span><span class="op">&gt;</span> {
<span class="bool-val">false</span> <span class="op">|</span><span class="op">|</span>
<span class="ident">synstructure_test_traits</span>::<span class="ident">Interest</span>::<span class="ident">interesting</span>(<span class="ident">__binding_0</span>)
}
}
}
}
};
}
}
}</pre></div>
<p>For more example usage, consider investigating the <code>abomonation_derive</code> crate,
which makes use of this crate, and is fairly simple.</p>
</div><h2 id='macros' class='section-header'><a href="#macros">Macros</a></h2>
<table><tr class='module-item'><td><a class="macro" href="macro.decl_attribute.html" title='synstructure::decl_attribute macro'>decl_attribute</a></td><td class='docblock-short'><p>The <code>decl_attribute!</code> macro declares a custom attribute wrapper. It will
parse the incoming <code>TokenStream</code> into a <code>synstructure::Structure</code> object,
and pass it into the inner function.</p>
</td></tr><tr class='module-item'><td><a class="macro" href="macro.decl_derive.html" title='synstructure::decl_derive macro'>decl_derive</a></td><td class='docblock-short'><p>The <code>decl_derive!</code> macro declares a custom derive wrapper. It will parse the
incoming <code>TokenStream</code> into a <code>synstructure::Structure</code> object, and pass it
into the inner function.</p>
</td></tr><tr class='module-item'><td><a class="macro" href="macro.test_derive.html" title='synstructure::test_derive macro'>test_derive</a></td><td class='docblock-short'><p>Run a test on a custom derive. This macro expands both the original struct
and the expansion to ensure that they compile correctly, and confirms that
feeding the original struct into the named derive will produce the written
output.</p>
</td></tr></table><h2 id='structs' class='section-header'><a href="#structs">Structs</a></h2>
<table><tr class='module-item'><td><a class="struct" href="struct.BindingInfo.html" title='synstructure::BindingInfo struct'>BindingInfo</a></td><td class='docblock-short'><p>Information about a specific binding. This contains both an <code>Ident</code>
reference to the given field, and the syn <code>&amp;'a Field</code> descriptor for that
field.</p>
</td></tr><tr class='module-item'><td><a class="struct" href="struct.Structure.html" title='synstructure::Structure struct'>Structure</a></td><td class='docblock-short'><p>A wrapper around a <code>syn::DeriveInput</code> which provides utilities for creating
custom derive trait implementations.</p>
</td></tr><tr class='module-item'><td><a class="struct" href="struct.VariantAst.html" title='synstructure::VariantAst struct'>VariantAst</a></td><td class='docblock-short'><p>This type is similar to <code>syn</code>'s <code>Variant</code> type, however each of the fields
are references rather than owned. When this is used as the AST for a real
variant, this struct simply borrows the fields of the <code>syn::Variant</code>,
however this type may also be used as the sole variant for a struct.</p>
</td></tr><tr class='module-item'><td><a class="struct" href="struct.VariantInfo.html" title='synstructure::VariantInfo struct'>VariantInfo</a></td><td class='docblock-short'><p>A wrapper around a <code>syn::DeriveInput</code>'s variant which provides utilities
for destructuring <code>Variant</code>s with <code>match</code> expressions.</p>
</td></tr></table><h2 id='enums' class='section-header'><a href="#enums">Enums</a></h2>
<table><tr class='module-item'><td><a class="enum" href="enum.AddBounds.html" title='synstructure::AddBounds enum'>AddBounds</a></td><td class='docblock-short'><p>Changes how bounds are added</p>
</td></tr><tr class='module-item'><td><a class="enum" href="enum.BindStyle.html" title='synstructure::BindStyle enum'>BindStyle</a></td><td class='docblock-short'><p>The type of binding to use when generating a pattern.</p>
</td></tr></table><h2 id='functions' class='section-header'><a href="#functions">Functions</a></h2>
<table><tr class='module-item'><td><a class="fn" href="fn.unpretty_print.html" title='synstructure::unpretty_print fn'>unpretty_print</a></td><td class='docblock-short'><p>Dumps an unpretty version of a tokenstream. Takes any type which implements
<code>Display</code>.</p>
</td></tr></table></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>&#9166;</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><p>Search multiple things at once by splitting your query with comma (e.g., <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../";window.currentCrate = "synstructure";</script><script src="../aliases.js"></script><script src="../main.js"></script><script defer src="../search-index.js"></script></body></html>