<!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="Lower level primitive types that are useful in a variety of circumstances."><title>regex_automata::util::primitives - 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-ac92e1bbe349e143.css"><metaname="rustdoc-vars"data-root-path="../../../"data-static-root-path="../../../static.files/"data-current-crate="regex_automata"data-themes=""data-resource-suffix=""data-rustdoc-version="1.76.0 (07dca489a 2024-02-04)"data-channel="1.76.0"data-search-js="search-2b6ce74ff89ae146.js"data-settings-js="settings-4313503d2e1961c2.js"><scriptsrc="../../../static.files/storage-f2adc0d6ca4d09fb.js"></script><scriptdefersrc="../sidebar-items.js"></script><scriptdefersrc="../../../static.files/main-305769736d49e732.js"></script><noscript><linkrel="stylesheet"href="../../../static.files/noscript-feafe1bb7466e4bd.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 mod"><!--[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">☰</button></nav><navclass="sidebar"><divclass="sidebar-crate"><h2><ahref="../../../regex_automata/index.html">regex_automata</a><spanclass="version">0.4.6</span></h2></div><h2class="location"><ahref="#">Module primitives</a></h2><divclass="sidebar-elems"><section><ulclass="block"><li><ahref="#structs">Structs</a></li></ul></section><h2><ahref="../index.html">In regex_automata::util</a></h2></div></nav><divclass="sidebar-resizer"></div>
<main><divclass="width-limiter"><navclass="sub"><formclass="search-form"><span></span><divid="sidebar-button"tabindex="-1"><ahref="../../../regex_automata/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>Module <ahref="../../index.html">regex_automata</a>::<wbr><ahref="../index.html">util</a>::<wbr><aclass="mod"href="#">primitives</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_automata/util/primitives.rs.html#1-776">source</a> · <buttonid="toggle-all-docs"title="collapse all docs">[<span>−</span>]</button></span></div><detailsclass="toggle top-doc"open><summaryclass="hideme"><span>Expand description</span></summary><divclass="docblock"><p>Lower level primitive types that are useful in a variety of circumstances.</p>
<p>This list represents the principle types in this module and briefly describes
when you might want to use them.</p>
<ul>
<li><ahref="../../struct.PatternID.html"title="struct regex_automata::PatternID"><code>PatternID</code></a> - A type that represents the identifier of a regex pattern.
This is probably the most widely used type in this module (which is why it’s
also re-exported in the crate root).</li>
<li><ahref="struct.StateID.html"title="struct regex_automata::util::primitives::StateID"><code>StateID</code></a> - A type the represents the identifier of a finite automaton
state. This is used for both NFAs and DFAs, with the notable exception of
the hybrid NFA/DFA. (The hybrid NFA/DFA uses a special purpose “lazy” state
identifier.)</li>
<li><ahref="struct.SmallIndex.html"title="struct regex_automata::util::primitives::SmallIndex"><code>SmallIndex</code></a> - The internal representation of both a <code>PatternID</code> and a
<code>StateID</code>. Its purpose is to serve as a type that can index memory without
being as big as a <code>usize</code> on 64-bit targets. The main idea behind this type
is that there are many things in regex engines that will, in practice, never
overflow a 32-bit integer. (For example, like the number of patterns in a regex
or the number of states in an NFA.) Thus, a <code>SmallIndex</code> can be used to index
memory without peppering <code>as</code> casts everywhere. Moreover, it forces callers
to handle errors in the case where, somehow, the value would otherwise overflow
either a 32-bit integer or a <code>usize</code> (e.g., on 16-bit targets).</li>
<li><ahref="struct.NonMaxUsize.html"title="struct regex_automata::util::primitives::NonMaxUsize"><code>NonMaxUsize</code></a> - Represents a <code>usize</code> that cannot be <code>usize::MAX</code>. As a
result, <code>Option<NonMaxUsize></code> has the same size in memory as a <code>usize</code>. This
useful, for example, when representing the offsets of submatches since it
reduces memory usage by a factor of 2. It is a legal optimization since Rust
guarantees that slices never have a length that exceeds <code>isize::MAX</code>.</li>
</ul>
</div></details><h2id="structs"class="section-header"><ahref="#structs">Structs</a></h2><ulclass="item-table"><li><divclass="item-name"><aclass="struct"href="struct.NonMaxUsize.html"title="struct regex_automata::util::primitives::NonMaxUsize">NonMaxUsize</a></div><divclass="desc docblock-short">A <code>usize</code> that can never be <code>usize::MAX</code>.</div></li><li><divclass="item-name"><aclass="struct"href="struct.PatternID.html"title="struct regex_automata::util::primitives::PatternID">PatternID</a></div><divclass="desc docblock-short">The identifier of a regex pattern, represented by a <ahref="struct.SmallIndex.html"title="struct regex_automata::util::primitives::SmallIndex"><code>SmallIndex</code></a>.</div></li><li><divclass="item-name"><aclass="struct"href="struct.PatternIDError.html"title="struct regex_automata::util::primitives::PatternIDError">PatternIDError</a></div><divclass="desc docblock-short">This error occurs when a value could not be constructed.</div></li><li><divclass="item-name"><aclass="struct"href="struct.SmallIndex.html"title="struct regex_automata::util::primitives::SmallIndex">SmallIndex</a></div><divclass="desc docblock-short">A type that represents a “small” index.</div></li><li><divclass="item-name"><aclass="struct"href="struct.SmallIndexError.html"title="struct regex_automata::util::primitives::SmallIndexError">SmallIndexError</a></div><divclass="desc docblock-short">This error occurs when a small index could not be constructed.</div></li><li><divclass="item-name"><aclass="struct"href="struct.StateID.html"title="struct regex_automata::util::primitives::StateID">StateID</a></div><divclass="desc docblock-short">The identifier of a finite automaton state, represented by a
<ahref="struct.SmallIndex.html"title="struct regex_automata::util::primitives::SmallIndex"><code>SmallIndex</code></a>.</div></li><li><divclass="item-name"><aclass="struct"href="struct.StateIDError.html"title="struct regex_automata::util::primitives::StateIDError">StateIDError</a></div><divclass="desc docblock-short">This error occurs when a value could not be constructed.</div></li></ul></section></div></main></body></html>
