| <!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="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/regex-1.8.3/src/sparse.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>sparse.rs - source</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="../../source-script.js"></script><script defer src="../../source-files.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 source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../regex/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../regex/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><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="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use </span>std::fmt; |
| <span class="kw">use </span>std::ops::Deref; |
| <span class="kw">use </span>std::slice; |
| |
| <span class="doccomment">/// A sparse set used for representing ordered NFA states. |
| /// |
| /// This supports constant time addition and membership testing. Clearing an |
| /// entire set can also be done in constant time. Iteration yields elements |
| /// in the order in which they were inserted. |
| /// |
| /// The data structure is based on: https://research.swtch.com/sparse |
| /// Note though that we don't actually use uninitialized memory. We generally |
| /// reuse allocations, so the initial allocation cost is bareable. However, |
| /// its other properties listed above are extremely useful. |
| </span><span class="attribute">#[derive(Clone)] |
| </span><span class="kw">pub struct </span>SparseSet { |
| <span class="doccomment">/// Dense contains the instruction pointers in the order in which they |
| /// were inserted. |
| </span>dense: Vec<usize>, |
| <span class="doccomment">/// Sparse maps instruction pointers to their location in dense. |
| /// |
| /// An instruction pointer is in the set if and only if |
| /// sparse[ip] < dense.len() && ip == dense[sparse[ip]]. |
| </span>sparse: Box<[usize]>, |
| } |
| |
| <span class="kw">impl </span>SparseSet { |
| <span class="kw">pub fn </span>new(size: usize) -> SparseSet { |
| SparseSet { |
| dense: Vec::with_capacity(size), |
| sparse: <span class="macro">vec!</span>[<span class="number">0</span>; size].into_boxed_slice(), |
| } |
| } |
| |
| <span class="kw">pub fn </span>len(<span class="kw-2">&</span><span class="self">self</span>) -> usize { |
| <span class="self">self</span>.dense.len() |
| } |
| |
| <span class="kw">pub fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <span class="self">self</span>.dense.is_empty() |
| } |
| |
| <span class="kw">pub fn </span>capacity(<span class="kw-2">&</span><span class="self">self</span>) -> usize { |
| <span class="self">self</span>.dense.capacity() |
| } |
| |
| <span class="kw">pub fn </span>insert(<span class="kw-2">&mut </span><span class="self">self</span>, value: usize) { |
| <span class="kw">let </span>i = <span class="self">self</span>.len(); |
| <span class="macro">assert!</span>(i < <span class="self">self</span>.capacity()); |
| <span class="self">self</span>.dense.push(value); |
| <span class="self">self</span>.sparse[value] = i; |
| } |
| |
| <span class="kw">pub fn </span>contains(<span class="kw-2">&</span><span class="self">self</span>, value: usize) -> bool { |
| <span class="kw">let </span>i = <span class="self">self</span>.sparse[value]; |
| <span class="self">self</span>.dense.get(i) == <span class="prelude-val">Some</span>(<span class="kw-2">&</span>value) |
| } |
| |
| <span class="kw">pub fn </span>clear(<span class="kw-2">&mut </span><span class="self">self</span>) { |
| <span class="self">self</span>.dense.clear(); |
| } |
| } |
| |
| <span class="kw">impl </span>fmt::Debug <span class="kw">for </span>SparseSet { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { |
| <span class="macro">write!</span>(f, <span class="string">"SparseSet({:?})"</span>, <span class="self">self</span>.dense) |
| } |
| } |
| |
| <span class="kw">impl </span>Deref <span class="kw">for </span>SparseSet { |
| <span class="kw">type </span>Target = [usize]; |
| |
| <span class="kw">fn </span>deref(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span><span class="self">Self</span>::Target { |
| <span class="kw-2">&</span><span class="self">self</span>.dense |
| } |
| } |
| |
| <span class="kw">impl</span><<span class="lifetime">'a</span>> IntoIterator <span class="kw">for </span><span class="kw-2">&</span><span class="lifetime">'a </span>SparseSet { |
| <span class="kw">type </span>Item = <span class="kw-2">&</span><span class="lifetime">'a </span>usize; |
| <span class="kw">type </span>IntoIter = slice::Iter<<span class="lifetime">'a</span>, usize>; |
| <span class="kw">fn </span>into_iter(<span class="self">self</span>) -> <span class="self">Self</span>::IntoIter { |
| <span class="self">self</span>.iter() |
| } |
| } |
| </code></pre></div> |
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