| <!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="A trait for visiting the high-level IR (HIR) in depth first order."><meta name="keywords" content="rust, rustlang, rust-lang, Visitor"><title>Visitor in regex_syntax::hir - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc trait"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../../regex_syntax/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../regex_syntax/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Visitor</a></h2><div class="sidebar-elems"><section><h3><a href="#required-associated-types">Required Associated Types</a></h3><ul class="block"><li><a href="#associatedtype.Err">Err</a></li><li><a href="#associatedtype.Output">Output</a></li></ul><h3><a href="#required-methods">Required Methods</a></h3><ul class="block"><li><a href="#tymethod.finish">finish</a></li></ul><h3><a href="#provided-methods">Provided Methods</a></h3><ul class="block"><li><a href="#method.start">start</a></li><li><a href="#method.visit_alternation_in">visit_alternation_in</a></li><li><a href="#method.visit_post">visit_post</a></li><li><a href="#method.visit_pre">visit_pre</a></li></ul><h3><a href="#implementors">Implementors</a></h3></section><h2><a href="index.html">In regex_syntax::hir</a></h2></div></nav><main><div class="width-limiter"><nav class="sub"><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn">Trait <a href="../index.html">regex_syntax</a>::<wbr><a href="index.html">hir</a>::<wbr><a class="trait" href="#">Visitor</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../../src/regex_syntax/hir/visitor.rs.html#15-44">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><div class="item-decl"><pre class="rust trait"><code>pub trait Visitor { |
| type <a href="#associatedtype.Output" class="associatedtype">Output</a>; |
| type <a href="#associatedtype.Err" class="associatedtype">Err</a>; |
| |
| fn <a href="#tymethod.finish" class="fnname">finish</a>(self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Output" title="type regex_syntax::hir::Visitor::Output">Output</a>, Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Err" title="type regex_syntax::hir::Visitor::Err">Err</a>>; |
| |
| fn <a href="#method.start" class="fnname">start</a>(&mut self) { ... } |
| <span class="item-spacer"></span> fn <a href="#method.visit_pre" class="fnname">visit_pre</a>(&mut self, _hir: &<a class="struct" href="struct.Hir.html" title="struct regex_syntax::hir::Hir">Hir</a>) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.unit.html">()</a>, Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Err" title="type regex_syntax::hir::Visitor::Err">Err</a>> { ... } |
| <span class="item-spacer"></span> fn <a href="#method.visit_post" class="fnname">visit_post</a>(&mut self, _hir: &<a class="struct" href="struct.Hir.html" title="struct regex_syntax::hir::Hir">Hir</a>) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.unit.html">()</a>, Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Err" title="type regex_syntax::hir::Visitor::Err">Err</a>> { ... } |
| <span class="item-spacer"></span> fn <a href="#method.visit_alternation_in" class="fnname">visit_alternation_in</a>(&mut self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.unit.html">()</a>, Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Err" title="type regex_syntax::hir::Visitor::Err">Err</a>> { ... } |
| }</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>A trait for visiting the high-level IR (HIR) in depth first order.</p> |
| <p>The principle aim of this trait is to enable callers to perform case |
| analysis on a high-level intermediate representation of a regular |
| expression without necessarily using recursion. In particular, this permits |
| callers to do case analysis with constant stack usage, which can be |
| important since the size of an HIR may be proportional to end user input.</p> |
| <p>Typical usage of this trait involves providing an implementation and then |
| running it using the <a href="fn.visit.html" title="visit"><code>visit</code></a> function.</p> |
| </div></details><h2 id="required-associated-types" class="small-section-header">Required Associated Types<a href="#required-associated-types" class="anchor"></a></h2><div class="methods"><details class="rustdoc-toggle method-toggle" open><summary><section id="associatedtype.Output" class="method has-srclink"><a class="srclink rightside" href="../../src/regex_syntax/hir/visitor.rs.html#17">source</a><h4 class="code-header">type <a href="#associatedtype.Output" class="associatedtype">Output</a></h4></section></summary><div class="docblock"><p>The result of visiting an HIR.</p> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="associatedtype.Err" class="method has-srclink"><a class="srclink rightside" href="../../src/regex_syntax/hir/visitor.rs.html#19">source</a><h4 class="code-header">type <a href="#associatedtype.Err" class="associatedtype">Err</a></h4></section></summary><div class="docblock"><p>An error that visiting an HIR might return.</p> |
| </div></details></div><h2 id="required-methods" class="small-section-header">Required Methods<a href="#required-methods" class="anchor"></a></h2><div class="methods"><details class="rustdoc-toggle method-toggle" open><summary><section id="tymethod.finish" class="method has-srclink"><a class="srclink rightside" href="../../src/regex_syntax/hir/visitor.rs.html#23">source</a><h4 class="code-header">fn <a href="#tymethod.finish" class="fnname">finish</a>(self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Output" title="type regex_syntax::hir::Visitor::Output">Output</a>, Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Err" title="type regex_syntax::hir::Visitor::Err">Err</a>></h4></section></summary><div class="docblock"><p>All implementors of <code>Visitor</code> must provide a <code>finish</code> method, which |
| yields the result of visiting the HIR or an error.</p> |
| </div></details></div><h2 id="provided-methods" class="small-section-header">Provided Methods<a href="#provided-methods" class="anchor"></a></h2><div class="methods"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.start" class="method has-srclink"><a class="srclink rightside" href="../../src/regex_syntax/hir/visitor.rs.html#26">source</a><h4 class="code-header">fn <a href="#method.start" class="fnname">start</a>(&mut self)</h4></section></summary><div class="docblock"><p>This method is called before beginning traversal of the HIR.</p> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.visit_pre" class="method has-srclink"><a class="srclink rightside" href="../../src/regex_syntax/hir/visitor.rs.html#30-32">source</a><h4 class="code-header">fn <a href="#method.visit_pre" class="fnname">visit_pre</a>(&mut self, _hir: &<a class="struct" href="struct.Hir.html" title="struct regex_syntax::hir::Hir">Hir</a>) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.unit.html">()</a>, Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Err" title="type regex_syntax::hir::Visitor::Err">Err</a>></h4></section></summary><div class="docblock"><p>This method is called on an <code>Hir</code> before descending into child <code>Hir</code> |
| nodes.</p> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.visit_post" class="method has-srclink"><a class="srclink rightside" href="../../src/regex_syntax/hir/visitor.rs.html#36-38">source</a><h4 class="code-header">fn <a href="#method.visit_post" class="fnname">visit_post</a>(&mut self, _hir: &<a class="struct" href="struct.Hir.html" title="struct regex_syntax::hir::Hir">Hir</a>) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.unit.html">()</a>, Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Err" title="type regex_syntax::hir::Visitor::Err">Err</a>></h4></section></summary><div class="docblock"><p>This method is called on an <code>Hir</code> after descending all of its child |
| <code>Hir</code> nodes.</p> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.visit_alternation_in" class="method has-srclink"><a class="srclink rightside" href="../../src/regex_syntax/hir/visitor.rs.html#41-43">source</a><h4 class="code-header">fn <a href="#method.visit_alternation_in" class="fnname">visit_alternation_in</a>(&mut self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.unit.html">()</a>, Self::<a class="associatedtype" href="trait.Visitor.html#associatedtype.Err" title="type regex_syntax::hir::Visitor::Err">Err</a>></h4></section></summary><div class="docblock"><p>This method is called between child nodes of an alternation.</p> |
| </div></details></div><h2 id="implementors" class="small-section-header">Implementors<a href="#implementors" class="anchor"></a></h2><div id="implementors-list"></div><script src="../../implementors/regex_syntax/hir/visitor/trait.Visitor.js" async></script></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="regex_syntax" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
