<!DOCTYPE html><htmllang="en"><head><metacharset="utf-8"><metaname="viewport"content="width=device-width, initial-scale=1.0"><metaname="generator"content="rustdoc"><metaname="description"content="Match multiple, possibly overlapping, regexes in a single search."><title>RegexSet in regex::bytes - Rust</title><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2"><linkrel="stylesheet"href="../../static.files/normalize-76eba96aa4d2e634.css"><linkrel="stylesheet"href="../../static.files/rustdoc-5bc39a1768837dd0.css"><metaname="rustdoc-vars"data-root-path="../../"data-static-root-path="../../static.files/"data-current-crate="regex"data-themes=""data-resource-suffix=""data-rustdoc-version="1.77.1 (7cf61ebde 2024-03-27)"data-channel="1.77.1"data-search-js="search-dd67cee4cfa65049.js"data-settings-js="settings-4313503d2e1961c2.js"><scriptsrc="../../static.files/storage-4c98445ec4002617.js"></script><scriptdefersrc="sidebar-items.js"></script><scriptdefersrc="../../static.files/main-48f368f3872407c8.js"></script><noscript><linkrel="stylesheet"href="../../static.files/noscript-04d5337699b92874.css"></noscript><linkrel="alternate icon"type="image/png"href="../../static.files/favicon-16x16-8b506e7a72182f1c.png"><linkrel="alternate icon"type="image/png"href="../../static.files/favicon-32x32-422f7d1d52889060.png"><linkrel="icon"type="image/svg+xml"href="../../static.files/favicon-2c020d218678b618.svg"></head><bodyclass="rustdoc struct"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><navclass="mobile-topbar"><buttonclass="sidebar-menu-toggle"title="show sidebar"></button></nav><navclass="sidebar"><divclass="sidebar-crate"><h2><ahref="../../regex/index.html">regex</a><spanclass="version">1.10.4</span></h2></div><h2class="location"><ahref="#">RegexSet</a></h2><divclass="sidebar-elems"><section><h3><ahref="#implementations">Methods</a></h3><ulclass="block method"><li><ahref="#method.empty">empty</a></li><li><ahref="#method.is_empty">is_empty</a></li><li><ahref="#method.is_match">is_match</a></li><li><ahref="#method.is_match_at">is_match_at</a></li><li><ahref="#method.len">len</a></li><li><ahref="#method.matches">matches</a></li><li><ahref="#method.matches_at">matches_at</a></li><li><ahref="#method.new">new</a></li><li><ahref="#method.patterns">patterns</a></li></ul><h3><ahref="#trait-implementations">Trait Implementations</a></h3><ulclass="block trait-implementation"><li><ahref="#impl-Clone-for-RegexSet">Clone</a></li><li><ahref="#impl-Debug-for-RegexSet">Debug</a></li><li><ahref="#impl-Default-for-RegexSet">Default</a></li></ul><h3><ahref="#synthetic-implementations">Auto Trait Implementations</a></h3><ulclass="block synthetic-implementation"><li><ahref="#impl-RefUnwindSafe-for-RegexSet">RefUnwindSafe</a></li><li><ahref="#impl-Send-for-RegexSet">Send</a></li><li><ahref="#impl-Sync-for-RegexSet">Sync</a></li><li><ahref="#impl-Unpin-for-RegexSet">Unpin</a></li><li><ahref="#impl-UnwindSafe-for-RegexSet">UnwindSafe</a></li></ul><h3><ahref="#blanket-implementations">Blanket Implementations</a></h3><ulclass="block blanket-implementation"><li><ahref="#impl-Any-for-T">Any</a></li><li><ahref="#impl-Borrow%3CT%3E-for-T">Borrow<T></a></li><li><ahref="#impl-BorrowMut%3CT%3E-for-T">BorrowMut<T></a></li><li><ahref="#impl-From%3CT%3E-for-T">From<T></a></li><li><ahref="#impl-Into%3CU
<main><divclass="width-limiter"><navclass="sub"><formclass="search-form"><span></span><divid="sidebar-button"tabindex="-1"><ahref="../../regex/all.html"title="show sidebar"></a></div><inputclass="search-input"name="search"aria-label="Run search in the documentation"autocomplete="off"spellcheck="false"placeholder="Click or press ‘S’ to search, ‘?’ for more options…"type="search"><divid="help-button"tabindex="-1"><ahref="../../help.html"title="help">?</a></div><divid="settings-menu"tabindex="-1"><ahref="../../settings.html"title="settings"><imgwidth="22"height="22"alt="Change settings"src="../../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><sectionid="main-content"class="content"><divclass="main-heading"><h1>Struct <ahref="../index.html">regex</a>::<wbr><ahref="index.html">bytes</a>::<wbr><aclass="struct"href="#">RegexSet</a><buttonid="copy-path"title="Copy item path to clipboard"><imgsrc="../../static.files/clipboard-7571035ce49a181d.svg"width="19"height="18"alt="Copy item path"></button></h1><spanclass="out-of-band"><aclass="src"href="../../src/regex/regexset/bytes.rs.html#136-139">source</a> · <buttonid="toggle-all-docs"title="collapse all docs">[<span>−</span>]</button></span></div><preclass="rust item-decl"><code>pub struct RegexSet { <spanclass="comment">/* private fields */</span> }</code></pre><detailsclass="toggle top-doc"open><summaryclass="hideme"><span>Expand description</span></summary><divclass="docblock"><p>Match multiple, possibly overlapping, regexes in a single search.</p>
<p>A regex set corresponds to the union of zero or more regular expressions.
That is, a regex set will match a haystack when at least one of its
constituent regexes matches. A regex set as its formulated here provides a
touch more power: it will also report <em>which</em> regular expressions in the
set match. Indeed, this is the key difference between regex sets and a
single <code>Regex</code> with many alternates, since only one alternate can match at
a time.</p>
<p>For example, consider regular expressions to match email addresses and
domains: <code>[a-z]+@[a-z]+\.(com|org|net)</code> and <code>[a-z]+\.(com|org|net)</code>. If a
regex set is constructed from those regexes, then searching the haystack
<code>foo@example.com</code> will report both regexes as matching. Of course, one
could accomplish this by compiling each regex on its own and doing two
searches over the haystack. The key advantage of using a regex set is
that it will report the matching regexes using a <em>single pass through the
haystack</em>. If one has hundreds or thousands of regexes to match repeatedly
(like a URL router for a complex web application or a user agent matcher),
then a regex set <em>can</em> realize huge performance gains.</p>
<p>Unlike the top-level <ahref="../struct.RegexSet.html"title="struct regex::RegexSet"><code>RegexSet</code></a>, this <code>RegexSet</code>
searches haystacks with type <code>&[u8]</code> instead of <code>&str</code>. Consequently, this
<code>RegexSet</code> is permitted to match invalid UTF-8.</p>
I: <aclass="trait"href="https://doc.rust-lang.org/1.77.1/core/iter/traits/collect/trait.IntoIterator.html"title="trait core::iter::traits::collect::IntoIterator">IntoIterator</a><Item = S>,</div></h4></section></summary><divclass="docblock"><p>Create a new regex set with the given regular expressions.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.is_match"class="method"><aclass="src rightside"href="../../src/regex/regexset/bytes.rs.html#214-216">source</a><h4class="code-header">pub fn <ahref="#method.is_match"class="fn">is_match</a>(&self, haystack: &[<aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.u8.html">u8</a>]) -><aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.bool.html">bool</a></h4></section></summary><divclass="docblock"><p>Returns true if and only if one of the regexes in this set matches
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.is_match_at"class="method"><aclass="src rightside"href="../../src/regex/regexset/bytes.rs.html#248-250">source</a><h4class="code-header">pub fn <ahref="#method.is_match_at"class="fn">is_match_at</a>(&self, haystack: &[<aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.u8.html">u8</a>], start: <aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.usize.html">usize</a>) -><aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.bool.html">bool</a></h4></section></summary><divclass="docblock"><p>Returns true if and only if one of the regexes in this set matches the
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.matches"class="method"><aclass="src rightside"href="../../src/regex/regexset/bytes.rs.html#291-293">source</a><h4class="code-header">pub fn <ahref="#method.matches"class="fn">matches</a>(&self, haystack: &[<aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.u8.html">u8</a>]) -><aclass="struct"href="struct.SetMatches.html"title="struct regex::bytes::SetMatches">SetMatches</a></h4></section></summary><divclass="docblock"><p>Returns the set of regexes that match in the given haystack.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.matches_at"class="method"><aclass="src rightside"href="../../src/regex/regexset/bytes.rs.html#329-334">source</a><h4class="code-header">pub fn <ahref="#method.matches_at"class="fn">matches_at</a>(&self, haystack: &[<aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.u8.html">u8</a>], start: <aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.usize.html">usize</a>) -><aclass="struct"href="struct.SetMatches.html"title="struct regex::bytes::SetMatches">SetMatches</a></h4></section></summary><divclass="docblock"><p>Returns the set of regexes that match in the given haystack.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.len"class="method"><aclass="src rightside"href="../../src/regex/regexset/bytes.rs.html#400-402">source</a><h4class="code-header">pub fn <ahref="#method.len"class="fn">len</a>(&self) -><aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.usize.html">usize</a></h4></section></summary><divclass="docblock"><p>Returns the total number of regexes in this set.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.is_empty"class="method"><aclass="src rightside"href="../../src/regex/regexset/bytes.rs.html#415-417">source</a><h4class="code-header">pub fn <ahref="#method.is_empty"class="fn">is_empty</a>(&self) -><aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.bool.html">bool</a></h4></section></summary><divclass="docblock"><p>Returns <code>true</code> if this set contains no regexes.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.patterns"class="method"><aclass="src rightside"href="../../src/regex/regexset/bytes.rs.html#448-450">source</a><h4class="code-header">pub fn <ahref="#method.patterns"class="fn">patterns</a>(&self) ->&[<aclass="struct"href="https://doc.rust-lang.org/1.77.1/alloc/string/struct.String.html"title="struct alloc::string::String">String</a>]</h4></section></summary><divclass="docblock"><p>Returns the regex patterns that this regex set was constructed from.</p>
<code><ahref="https://doc.rust-lang.org/1.77.1/core/convert/trait.From.html"title="trait core::convert::From">From</a><T> for U</code> chooses to do.</p>
</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-ToOwned-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.77.1/src/alloc/borrow.rs.html#83-85">source</a><ahref="#impl-ToOwned-for-T"class="anchor">§</a><h3class="code-header">impl<T><aclass="trait"href="https://doc.rust-lang.org/1.77.1/alloc/borrow/trait.ToOwned.html"title="trait alloc::borrow::ToOwned">ToOwned</a> for T<divclass="where">where
T: <aclass="trait"href="https://doc.rust-lang.org/1.77.1/core/clone/trait.Clone.html"title="trait core::clone::Clone">Clone</a>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Owned"class="associatedtype trait-impl"><ahref="#associatedtype.Owned"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.77.1/alloc/borrow/trait.ToOwned.html#associatedtype.Owned"class="associatedtype">Owned</a> = T</h4></section></summary><divclass='docblock'>The resulting type after obtaining ownership.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.to_owned"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.77.1/src/alloc/borrow.rs.html#88">source</a><ahref="#method.to_owned"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.77.1/alloc/borrow/trait.ToOwned.html#tymethod.to_owned"class="fn">to_owned</a>(&self) -> T</h4></section></summary><divclass='docblock'>Creates owned data from borrowed data, usually by cloning. <ahref="https://doc.rust-lang.org/1.77.1/alloc/borrow/trait.ToOwned.html#tymethod.to_owned">Read more</a></div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.clone_into"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.77.1/src/alloc/borrow.rs.html#92">source</a><ahref="#method.clone_into"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.77.1/alloc/borrow/trait.ToOwned.html#method.clone_into"class="fn">clone_into</a>(&self, target: <aclass="primitive"href="https://doc.rust-lang.org/1.77.1/std/primitive.reference.html">&mut T</a>)</h4></section></summary><divclass='docblock'>Uses borrowed data to replace owned data, usually by cloning. <ahref="https://doc.rust-lang.org/1.77.1/alloc/borrow/trait.ToOwned.html#method.clone_into">Read more</a></div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryFrom%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.77.1/src/core/convert/mod.rs.html#804-806">source</a><ahref="#impl-TryFrom%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.Into.html"title="trait core::convert::Into">Into</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error-1"class="associatedtype trait-impl"><ahref="#associatedtype.Error-1"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html#associatedtype.Error"class="associatedtype">Error</a> = <aclass="enum"href="https://doc.rust-lang.org/1.77.1/core/convert/enum.Infallible.html"title="enum core::convert::Infallible">Infallible</a></h4></section></summary><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_from"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.77.1/src/core/convert/mod.rs.html#811">source</a><ahref="#method.try_from"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html#tymethod.try_from"class="fn">try_from</a>(value: U) -><aclass="enum"href="https://doc.rust-lang.org/1.77.1/core/result/enum.Result.html"title="enum core::result::Result">Result</a><T, <T as <aclass="trait"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><divclass='docblock'>Performs the conversion.</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryInto%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.77.1/src/core/convert/mod.rs.html#789-791">source</a><ahref="#impl-TryInto%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryInto.html"title="trait core::convert::TryInto">TryInto</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error"class="associatedtype trait-impl"><ahref="#associatedtype.Error"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryInto.html#associatedtype.Error"class="associatedtype">Error</a> = <U as <aclass="trait"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a></h4></section></summary><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_into"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.77.1/src/core/convert/mod.rs.html#796">source</a><ahref="#method.try_into"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryInto.html#tymethod.try_into"class="fn">try_into</a>(self) -><aclass="enum"href="https://doc.rust-lang.org/1.77.1/core/result/enum.Result.html"title="enum core::result::Result">Result</a><U, <U as <aclass="trait"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.77.1/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><divclass='docblock'>Performs the conversion.</div></details></div></details></div></section></div></main></body></html>
