Google Git
Sign in
apache / incubator-teaclave-website / refs/heads/asf-site / . / api-docs / crates-enclave / src / regex / prog.rs.html
blob: 979e438ab926c1626b92d734cd1318773638113d [file] [log] [blame]
<!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/prog.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>prog.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>
<span id="2">2</span>
<span id="3">3</span>
<span id="4">4</span>
<span id="5">5</span>
<span id="6">6</span>
<span id="7">7</span>
<span id="8">8</span>
<span id="9">9</span>
<span id="10">10</span>
<span id="11">11</span>
<span id="12">12</span>
<span id="13">13</span>
<span id="14">14</span>
<span id="15">15</span>
<span id="16">16</span>
<span id="17">17</span>
<span id="18">18</span>
<span id="19">19</span>
<span id="20">20</span>
<span id="21">21</span>
<span id="22">22</span>
<span id="23">23</span>
<span id="24">24</span>
<span id="25">25</span>
<span id="26">26</span>
<span id="27">27</span>
<span id="28">28</span>
<span id="29">29</span>
<span id="30">30</span>
<span id="31">31</span>
<span id="32">32</span>
<span id="33">33</span>
<span id="34">34</span>
<span id="35">35</span>
<span id="36">36</span>
<span id="37">37</span>
<span id="38">38</span>
<span id="39">39</span>
<span id="40">40</span>
<span id="41">41</span>
<span id="42">42</span>
<span id="43">43</span>
<span id="44">44</span>
<span id="45">45</span>
<span id="46">46</span>
<span id="47">47</span>
<span id="48">48</span>
<span id="49">49</span>
<span id="50">50</span>
<span id="51">51</span>
<span id="52">52</span>
<span id="53">53</span>
<span id="54">54</span>
<span id="55">55</span>
<span id="56">56</span>
<span id="57">57</span>
<span id="58">58</span>
<span id="59">59</span>
<span id="60">60</span>
<span id="61">61</span>
<span id="62">62</span>
<span id="63">63</span>
<span id="64">64</span>
<span id="65">65</span>
<span id="66">66</span>
<span id="67">67</span>
<span id="68">68</span>
<span id="69">69</span>
<span id="70">70</span>
<span id="71">71</span>
<span id="72">72</span>
<span id="73">73</span>
<span id="74">74</span>
<span id="75">75</span>
<span id="76">76</span>
<span id="77">77</span>
<span id="78">78</span>
<span id="79">79</span>
<span id="80">80</span>
<span id="81">81</span>
<span id="82">82</span>
<span id="83">83</span>
<span id="84">84</span>
<span id="85">85</span>
<span id="86">86</span>
<span id="87">87</span>
<span id="88">88</span>
<span id="89">89</span>
<span id="90">90</span>
<span id="91">91</span>
<span id="92">92</span>
<span id="93">93</span>
<span id="94">94</span>
<span id="95">95</span>
<span id="96">96</span>
<span id="97">97</span>
<span id="98">98</span>
<span id="99">99</span>
<span id="100">100</span>
<span id="101">101</span>
<span id="102">102</span>
<span id="103">103</span>
<span id="104">104</span>
<span id="105">105</span>
<span id="106">106</span>
<span id="107">107</span>
<span id="108">108</span>
<span id="109">109</span>
<span id="110">110</span>
<span id="111">111</span>
<span id="112">112</span>
<span id="113">113</span>
<span id="114">114</span>
<span id="115">115</span>
<span id="116">116</span>
<span id="117">117</span>
<span id="118">118</span>
<span id="119">119</span>
<span id="120">120</span>
<span id="121">121</span>
<span id="122">122</span>
<span id="123">123</span>
<span id="124">124</span>
<span id="125">125</span>
<span id="126">126</span>
<span id="127">127</span>
<span id="128">128</span>
<span id="129">129</span>
<span id="130">130</span>
<span id="131">131</span>
<span id="132">132</span>
<span id="133">133</span>
<span id="134">134</span>
<span id="135">135</span>
<span id="136">136</span>
<span id="137">137</span>
<span id="138">138</span>
<span id="139">139</span>
<span id="140">140</span>
<span id="141">141</span>
<span id="142">142</span>
<span id="143">143</span>
<span id="144">144</span>
<span id="145">145</span>
<span id="146">146</span>
<span id="147">147</span>
<span id="148">148</span>
<span id="149">149</span>
<span id="150">150</span>
<span id="151">151</span>
<span id="152">152</span>
<span id="153">153</span>
<span id="154">154</span>
<span id="155">155</span>
<span id="156">156</span>
<span id="157">157</span>
<span id="158">158</span>
<span id="159">159</span>
<span id="160">160</span>
<span id="161">161</span>
<span id="162">162</span>
<span id="163">163</span>
<span id="164">164</span>
<span id="165">165</span>
<span id="166">166</span>
<span id="167">167</span>
<span id="168">168</span>
<span id="169">169</span>
<span id="170">170</span>
<span id="171">171</span>
<span id="172">172</span>
<span id="173">173</span>
<span id="174">174</span>
<span id="175">175</span>
<span id="176">176</span>
<span id="177">177</span>
<span id="178">178</span>
<span id="179">179</span>
<span id="180">180</span>
<span id="181">181</span>
<span id="182">182</span>
<span id="183">183</span>
<span id="184">184</span>
<span id="185">185</span>
<span id="186">186</span>
<span id="187">187</span>
<span id="188">188</span>
<span id="189">189</span>
<span id="190">190</span>
<span id="191">191</span>
<span id="192">192</span>
<span id="193">193</span>
<span id="194">194</span>
<span id="195">195</span>
<span id="196">196</span>
<span id="197">197</span>
<span id="198">198</span>
<span id="199">199</span>
<span id="200">200</span>
<span id="201">201</span>
<span id="202">202</span>
<span id="203">203</span>
<span id="204">204</span>
<span id="205">205</span>
<span id="206">206</span>
<span id="207">207</span>
<span id="208">208</span>
<span id="209">209</span>
<span id="210">210</span>
<span id="211">211</span>
<span id="212">212</span>
<span id="213">213</span>
<span id="214">214</span>
<span id="215">215</span>
<span id="216">216</span>
<span id="217">217</span>
<span id="218">218</span>
<span id="219">219</span>
<span id="220">220</span>
<span id="221">221</span>
<span id="222">222</span>
<span id="223">223</span>
<span id="224">224</span>
<span id="225">225</span>
<span id="226">226</span>
<span id="227">227</span>
<span id="228">228</span>
<span id="229">229</span>
<span id="230">230</span>
<span id="231">231</span>
<span id="232">232</span>
<span id="233">233</span>
<span id="234">234</span>
<span id="235">235</span>
<span id="236">236</span>
<span id="237">237</span>
<span id="238">238</span>
<span id="239">239</span>
<span id="240">240</span>
<span id="241">241</span>
<span id="242">242</span>
<span id="243">243</span>
<span id="244">244</span>
<span id="245">245</span>
<span id="246">246</span>
<span id="247">247</span>
<span id="248">248</span>
<span id="249">249</span>
<span id="250">250</span>
<span id="251">251</span>
<span id="252">252</span>
<span id="253">253</span>
<span id="254">254</span>
<span id="255">255</span>
<span id="256">256</span>
<span id="257">257</span>
<span id="258">258</span>
<span id="259">259</span>
<span id="260">260</span>
<span id="261">261</span>
<span id="262">262</span>
<span id="263">263</span>
<span id="264">264</span>
<span id="265">265</span>
<span id="266">266</span>
<span id="267">267</span>
<span id="268">268</span>
<span id="269">269</span>
<span id="270">270</span>
<span id="271">271</span>
<span id="272">272</span>
<span id="273">273</span>
<span id="274">274</span>
<span id="275">275</span>
<span id="276">276</span>
<span id="277">277</span>
<span id="278">278</span>
<span id="279">279</span>
<span id="280">280</span>
<span id="281">281</span>
<span id="282">282</span>
<span id="283">283</span>
<span id="284">284</span>
<span id="285">285</span>
<span id="286">286</span>
<span id="287">287</span>
<span id="288">288</span>
<span id="289">289</span>
<span id="290">290</span>
<span id="291">291</span>
<span id="292">292</span>
<span id="293">293</span>
<span id="294">294</span>
<span id="295">295</span>
<span id="296">296</span>
<span id="297">297</span>
<span id="298">298</span>
<span id="299">299</span>
<span id="300">300</span>
<span id="301">301</span>
<span id="302">302</span>
<span id="303">303</span>
<span id="304">304</span>
<span id="305">305</span>
<span id="306">306</span>
<span id="307">307</span>
<span id="308">308</span>
<span id="309">309</span>
<span id="310">310</span>
<span id="311">311</span>
<span id="312">312</span>
<span id="313">313</span>
<span id="314">314</span>
<span id="315">315</span>
<span id="316">316</span>
<span id="317">317</span>
<span id="318">318</span>
<span id="319">319</span>
<span id="320">320</span>
<span id="321">321</span>
<span id="322">322</span>
<span id="323">323</span>
<span id="324">324</span>
<span id="325">325</span>
<span id="326">326</span>
<span id="327">327</span>
<span id="328">328</span>
<span id="329">329</span>
<span id="330">330</span>
<span id="331">331</span>
<span id="332">332</span>
<span id="333">333</span>
<span id="334">334</span>
<span id="335">335</span>
<span id="336">336</span>
<span id="337">337</span>
<span id="338">338</span>
<span id="339">339</span>
<span id="340">340</span>
<span id="341">341</span>
<span id="342">342</span>
<span id="343">343</span>
<span id="344">344</span>
<span id="345">345</span>
<span id="346">346</span>
<span id="347">347</span>
<span id="348">348</span>
<span id="349">349</span>
<span id="350">350</span>
<span id="351">351</span>
<span id="352">352</span>
<span id="353">353</span>
<span id="354">354</span>
<span id="355">355</span>
<span id="356">356</span>
<span id="357">357</span>
<span id="358">358</span>
<span id="359">359</span>
<span id="360">360</span>
<span id="361">361</span>
<span id="362">362</span>
<span id="363">363</span>
<span id="364">364</span>
<span id="365">365</span>
<span id="366">366</span>
<span id="367">367</span>
<span id="368">368</span>
<span id="369">369</span>
<span id="370">370</span>
<span id="371">371</span>
<span id="372">372</span>
<span id="373">373</span>
<span id="374">374</span>
<span id="375">375</span>
<span id="376">376</span>
<span id="377">377</span>
<span id="378">378</span>
<span id="379">379</span>
<span id="380">380</span>
<span id="381">381</span>
<span id="382">382</span>
<span id="383">383</span>
<span id="384">384</span>
<span id="385">385</span>
<span id="386">386</span>
<span id="387">387</span>
<span id="388">388</span>
<span id="389">389</span>
<span id="390">390</span>
<span id="391">391</span>
<span id="392">392</span>
<span id="393">393</span>
<span id="394">394</span>
<span id="395">395</span>
<span id="396">396</span>
<span id="397">397</span>
<span id="398">398</span>
<span id="399">399</span>
<span id="400">400</span>
<span id="401">401</span>
<span id="402">402</span>
<span id="403">403</span>
<span id="404">404</span>
<span id="405">405</span>
<span id="406">406</span>
<span id="407">407</span>
<span id="408">408</span>
<span id="409">409</span>
<span id="410">410</span>
<span id="411">411</span>
<span id="412">412</span>
<span id="413">413</span>
<span id="414">414</span>
<span id="415">415</span>
<span id="416">416</span>
<span id="417">417</span>
<span id="418">418</span>
<span id="419">419</span>
<span id="420">420</span>
<span id="421">421</span>
<span id="422">422</span>
<span id="423">423</span>
<span id="424">424</span>
<span id="425">425</span>
<span id="426">426</span>
<span id="427">427</span>
<span id="428">428</span>
<span id="429">429</span>
<span id="430">430</span>
<span id="431">431</span>
<span id="432">432</span>
<span id="433">433</span>
<span id="434">434</span>
<span id="435">435</span>
<span id="436">436</span>
<span id="437">437</span>
<span id="438">438</span>
<span id="439">439</span>
<span id="440">440</span>
<span id="441">441</span>
<span id="442">442</span>
<span id="443">443</span>
<span id="444">444</span>
<span id="445">445</span>
<span id="446">446</span>
<span id="447">447</span>
<span id="448">448</span>
<span id="449">449</span>
<span id="450">450</span>
<span id="451">451</span>
</pre><pre class="rust"><code><span class="kw">use </span>std::cmp::Ordering;
<span class="kw">use </span>std::collections::HashMap;
<span class="kw">use </span>std::fmt;
<span class="kw">use </span>std::mem;
<span class="kw">use </span>std::ops::Deref;
<span class="kw">use </span>std::slice;
<span class="kw">use </span>std::sync::Arc;
<span class="kw">use </span><span class="kw">crate</span>::input::Char;
<span class="kw">use </span><span class="kw">crate</span>::literal::LiteralSearcher;
<span class="doccomment">/// `InstPtr` represents the index of an instruction in a regex program.
</span><span class="kw">pub type </span>InstPtr = usize;
<span class="doccomment">/// Program is a sequence of instructions and various facts about thos
/// instructions.
</span><span class="attribute">#[derive(Clone)]
</span><span class="kw">pub struct </span>Program {
<span class="doccomment">/// A sequence of instructions that represents an NFA.
</span><span class="kw">pub </span>insts: Vec&lt;Inst&gt;,
<span class="doccomment">/// Pointers to each Match instruction in the sequence.
///
/// This is always length 1 unless this program represents a regex set.
</span><span class="kw">pub </span>matches: Vec&lt;InstPtr&gt;,
<span class="doccomment">/// The ordered sequence of all capture groups extracted from the AST.
/// Unnamed groups are `None`.
</span><span class="kw">pub </span>captures: Vec&lt;<span class="prelude-ty">Option</span>&lt;String&gt;&gt;,
<span class="doccomment">/// Pointers to all named capture groups into `captures`.
</span><span class="kw">pub </span>capture_name_idx: Arc&lt;HashMap&lt;String, usize&gt;&gt;,
<span class="doccomment">/// If the number of capture groups is the same for all possible matches,
/// then this is that number.
</span><span class="kw">pub </span>static_captures_len: <span class="prelude-ty">Option</span>&lt;usize&gt;,
<span class="doccomment">/// A pointer to the start instruction. This can vary depending on how
/// the program was compiled. For example, programs for use with the DFA
/// engine have a `.*?` inserted at the beginning of unanchored regular
/// expressions. The actual starting point of the program is after the
/// `.*?`.
</span><span class="kw">pub </span>start: InstPtr,
<span class="doccomment">/// A set of equivalence classes for discriminating bytes in the compiled
/// program.
</span><span class="kw">pub </span>byte_classes: Vec&lt;u8&gt;,
<span class="doccomment">/// When true, this program can only match valid UTF-8.
</span><span class="kw">pub </span>only_utf8: bool,
<span class="doccomment">/// When true, this program uses byte range instructions instead of Unicode
/// range instructions.
</span><span class="kw">pub </span>is_bytes: bool,
<span class="doccomment">/// When true, the program is compiled for DFA matching. For example, this
/// implies `is_bytes` and also inserts a preceding `.*?` for unanchored
/// regexes.
</span><span class="kw">pub </span>is_dfa: bool,
<span class="doccomment">/// When true, the program matches text in reverse (for use only in the
/// DFA).
</span><span class="kw">pub </span>is_reverse: bool,
<span class="doccomment">/// Whether the regex must match from the start of the input.
</span><span class="kw">pub </span>is_anchored_start: bool,
<span class="doccomment">/// Whether the regex must match at the end of the input.
</span><span class="kw">pub </span>is_anchored_end: bool,
<span class="doccomment">/// Whether this program contains a Unicode word boundary instruction.
</span><span class="kw">pub </span>has_unicode_word_boundary: bool,
<span class="doccomment">/// A possibly empty machine for very quickly matching prefix literals.
</span><span class="kw">pub </span>prefixes: LiteralSearcher,
<span class="doccomment">/// A limit on the size of the cache that the DFA is allowed to use while
/// matching.
///
/// The cache limit specifies approximately how much space we&#39;re willing to
/// give to the state cache. Once the state cache exceeds the size, it is
/// wiped and all states must be re-computed.
///
/// Note that this value does not impact correctness. It can be set to 0
/// and the DFA will run just fine. (It will only ever store exactly one
/// state in the cache, and will likely run very slowly, but it will work.)
///
/// Also note that this limit is *per thread of execution*. That is,
/// if the same regex is used to search text across multiple threads
/// simultaneously, then the DFA cache is not shared. Instead, copies are
/// made.
</span><span class="kw">pub </span>dfa_size_limit: usize,
}
<span class="kw">impl </span>Program {
<span class="doccomment">/// Creates an empty instruction sequence. Fields are given default
/// values.
</span><span class="kw">pub fn </span>new() -&gt; <span class="self">Self </span>{
Program {
insts: <span class="macro">vec!</span>[],
matches: <span class="macro">vec!</span>[],
captures: <span class="macro">vec!</span>[],
capture_name_idx: Arc::new(HashMap::new()),
static_captures_len: <span class="prelude-val">None</span>,
start: <span class="number">0</span>,
byte_classes: <span class="macro">vec!</span>[<span class="number">0</span>; <span class="number">256</span>],
only_utf8: <span class="bool-val">true</span>,
is_bytes: <span class="bool-val">false</span>,
is_dfa: <span class="bool-val">false</span>,
is_reverse: <span class="bool-val">false</span>,
is_anchored_start: <span class="bool-val">false</span>,
is_anchored_end: <span class="bool-val">false</span>,
has_unicode_word_boundary: <span class="bool-val">false</span>,
prefixes: LiteralSearcher::empty(),
dfa_size_limit: <span class="number">2 </span>* (<span class="number">1 </span>&lt;&lt; <span class="number">20</span>),
}
}
<span class="doccomment">/// If pc is an index to a no-op instruction (like Save), then return the
/// next pc that is not a no-op instruction.
</span><span class="kw">pub fn </span>skip(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="kw-2">mut </span>pc: usize) -&gt; usize {
<span class="kw">loop </span>{
<span class="kw">match </span><span class="self">self</span>[pc] {
Inst::Save(<span class="kw-2">ref </span>i) =&gt; pc = i.goto,
<span class="kw">_ </span>=&gt; <span class="kw">return </span>pc,
}
}
}
<span class="doccomment">/// Return true if and only if an execution engine at instruction `pc` will
/// always lead to a match.
</span><span class="kw">pub fn </span>leads_to_match(<span class="kw-2">&amp;</span><span class="self">self</span>, pc: usize) -&gt; bool {
<span class="kw">if </span><span class="self">self</span>.matches.len() &gt; <span class="number">1 </span>{
<span class="comment">// If we have a regex set, then we have more than one ending
// state, so leading to one of those states is generally
// meaningless.
</span><span class="kw">return </span><span class="bool-val">false</span>;
}
<span class="kw">match </span><span class="self">self</span>[<span class="self">self</span>.skip(pc)] {
Inst::Match(<span class="kw">_</span>) =&gt; <span class="bool-val">true</span>,
<span class="kw">_ </span>=&gt; <span class="bool-val">false</span>,
}
}
<span class="doccomment">/// Returns true if the current configuration demands that an implicit
/// `.*?` be prepended to the instruction sequence.
</span><span class="kw">pub fn </span>needs_dotstar(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; bool {
<span class="self">self</span>.is_dfa &amp;&amp; !<span class="self">self</span>.is_reverse &amp;&amp; !<span class="self">self</span>.is_anchored_start
}
<span class="doccomment">/// Returns true if this program uses Byte instructions instead of
/// Char/Range instructions.
</span><span class="kw">pub fn </span>uses_bytes(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; bool {
<span class="self">self</span>.is_bytes || <span class="self">self</span>.is_dfa
}
<span class="doccomment">/// Returns true if this program exclusively matches valid UTF-8 bytes.
///
/// That is, if an invalid UTF-8 byte is seen, then no match is possible.
</span><span class="kw">pub fn </span>only_utf8(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; bool {
<span class="self">self</span>.only_utf8
}
<span class="doccomment">/// Return the approximate heap usage of this instruction sequence in
/// bytes.
</span><span class="kw">pub fn </span>approximate_size(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; usize {
<span class="comment">// The only instruction that uses heap space is Ranges (for
// Unicode codepoint programs) to store non-overlapping codepoint
// ranges. To keep this operation constant time, we ignore them.
</span>(<span class="self">self</span>.len() * mem::size_of::&lt;Inst&gt;())
+ (<span class="self">self</span>.matches.len() * mem::size_of::&lt;InstPtr&gt;())
+ (<span class="self">self</span>.captures.len() * mem::size_of::&lt;<span class="prelude-ty">Option</span>&lt;String&gt;&gt;())
+ (<span class="self">self</span>.capture_name_idx.len()
* (mem::size_of::&lt;String&gt;() + mem::size_of::&lt;usize&gt;()))
+ (<span class="self">self</span>.byte_classes.len() * mem::size_of::&lt;u8&gt;())
+ <span class="self">self</span>.prefixes.approximate_size()
}
}
<span class="kw">impl </span>Deref <span class="kw">for </span>Program {
<span class="kw">type </span>Target = [Inst];
<span class="attribute">#[cfg_attr(feature = <span class="string">&quot;perf-inline&quot;</span>, inline(always))]
</span><span class="kw">fn </span>deref(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="kw-2">&amp;</span><span class="self">Self</span>::Target {
<span class="kw-2">&amp;*</span><span class="self">self</span>.insts
}
}
<span class="kw">impl </span>fmt::Debug <span class="kw">for </span>Program {
<span class="kw">fn </span>fmt(<span class="kw-2">&amp;</span><span class="self">self</span>, f: <span class="kw-2">&amp;mut </span>fmt::Formatter&lt;<span class="lifetime">&#39;_</span>&gt;) -&gt; fmt::Result {
<span class="kw">use </span><span class="self">self</span>::Inst::<span class="kw-2">*</span>;
<span class="kw">fn </span>with_goto(cur: usize, goto: usize, fmtd: String) -&gt; String {
<span class="kw">if </span>goto == cur + <span class="number">1 </span>{
fmtd
} <span class="kw">else </span>{
<span class="macro">format!</span>(<span class="string">&quot;{} (goto: {})&quot;</span>, fmtd, goto)
}
}
<span class="kw">fn </span>visible_byte(b: u8) -&gt; String {
<span class="kw">use </span>std::ascii::escape_default;
<span class="kw">let </span>escaped = escape_default(b).collect::&lt;Vec&lt;u8&gt;&gt;();
String::from_utf8_lossy(<span class="kw-2">&amp;</span>escaped).into_owned()
}
<span class="kw">for </span>(pc, inst) <span class="kw">in </span><span class="self">self</span>.iter().enumerate() {
<span class="kw">match </span><span class="kw-2">*</span>inst {
Match(slot) =&gt; <span class="macro">write!</span>(f, <span class="string">&quot;{:04} Match({:?})&quot;</span>, pc, slot)<span class="question-mark">?</span>,
Save(<span class="kw-2">ref </span>inst) =&gt; {
<span class="kw">let </span>s = <span class="macro">format!</span>(<span class="string">&quot;{:04} Save({})&quot;</span>, pc, inst.slot);
<span class="macro">write!</span>(f, <span class="string">&quot;{}&quot;</span>, with_goto(pc, inst.goto, s))<span class="question-mark">?</span>;
}
Split(<span class="kw-2">ref </span>inst) =&gt; {
<span class="macro">write!</span>(
f,
<span class="string">&quot;{:04} Split({}, {})&quot;</span>,
pc, inst.goto1, inst.goto2
)<span class="question-mark">?</span>;
}
EmptyLook(<span class="kw-2">ref </span>inst) =&gt; {
<span class="kw">let </span>s = <span class="macro">format!</span>(<span class="string">&quot;{:?}&quot;</span>, inst.look);
<span class="macro">write!</span>(f, <span class="string">&quot;{:04} {}&quot;</span>, pc, with_goto(pc, inst.goto, s))<span class="question-mark">?</span>;
}
Char(<span class="kw-2">ref </span>inst) =&gt; {
<span class="kw">let </span>s = <span class="macro">format!</span>(<span class="string">&quot;{:?}&quot;</span>, inst.c);
<span class="macro">write!</span>(f, <span class="string">&quot;{:04} {}&quot;</span>, pc, with_goto(pc, inst.goto, s))<span class="question-mark">?</span>;
}
Ranges(<span class="kw-2">ref </span>inst) =&gt; {
<span class="kw">let </span>ranges = inst
.ranges
.iter()
.map(|r| <span class="macro">format!</span>(<span class="string">&quot;{:?}-{:?}&quot;</span>, r.<span class="number">0</span>, r.<span class="number">1</span>))
.collect::&lt;Vec&lt;String&gt;&gt;()
.join(<span class="string">&quot;, &quot;</span>);
<span class="macro">write!</span>(
f,
<span class="string">&quot;{:04} {}&quot;</span>,
pc,
with_goto(pc, inst.goto, ranges)
)<span class="question-mark">?</span>;
}
Bytes(<span class="kw-2">ref </span>inst) =&gt; {
<span class="kw">let </span>s = <span class="macro">format!</span>(
<span class="string">&quot;Bytes({}, {})&quot;</span>,
visible_byte(inst.start),
visible_byte(inst.end)
);
<span class="macro">write!</span>(f, <span class="string">&quot;{:04} {}&quot;</span>, pc, with_goto(pc, inst.goto, s))<span class="question-mark">?</span>;
}
}
<span class="kw">if </span>pc == <span class="self">self</span>.start {
<span class="macro">write!</span>(f, <span class="string">&quot; (start)&quot;</span>)<span class="question-mark">?</span>;
}
<span class="macro">writeln!</span>(f)<span class="question-mark">?</span>;
}
<span class="prelude-val">Ok</span>(())
}
}
<span class="kw">impl</span>&lt;<span class="lifetime">&#39;a</span>&gt; IntoIterator <span class="kw">for </span><span class="kw-2">&amp;</span><span class="lifetime">&#39;a </span>Program {
<span class="kw">type </span>Item = <span class="kw-2">&amp;</span><span class="lifetime">&#39;a </span>Inst;
<span class="kw">type </span>IntoIter = slice::Iter&lt;<span class="lifetime">&#39;a</span>, Inst&gt;;
<span class="kw">fn </span>into_iter(<span class="self">self</span>) -&gt; <span class="self">Self</span>::IntoIter {
<span class="self">self</span>.iter()
}
}
<span class="doccomment">/// Inst is an instruction code in a Regex program.
///
/// Regrettably, a regex program either contains Unicode codepoint
/// instructions (Char and Ranges) or it contains byte instructions (Bytes).
/// A regex program can never contain both.
///
/// It would be worth investigating splitting this into two distinct types and
/// then figuring out how to make the matching engines polymorphic over those
/// types without sacrificing performance.
///
/// Other than the benefit of moving invariants into the type system, another
/// benefit is the decreased size. If we remove the `Char` and `Ranges`
/// instructions from the `Inst` enum, then its size shrinks from 32 bytes to
/// 24 bytes. (This is because of the removal of a `Box&lt;[]&gt;` in the `Ranges`
/// variant.) Given that byte based machines are typically much bigger than
/// their Unicode analogues (because they can decode UTF-8 directly), this ends
/// up being a pretty significant savings.
</span><span class="attribute">#[derive(Clone, Debug)]
</span><span class="kw">pub enum </span>Inst {
<span class="doccomment">/// Match indicates that the program has reached a match state.
///
/// The number in the match corresponds to the Nth logical regular
/// expression in this program. This index is always 0 for normal regex
/// programs. Values greater than 0 appear when compiling regex sets, and
/// each match instruction gets its own unique value. The value corresponds
/// to the Nth regex in the set.
</span>Match(usize),
<span class="doccomment">/// Save causes the program to save the current location of the input in
/// the slot indicated by InstSave.
</span>Save(InstSave),
<span class="doccomment">/// Split causes the program to diverge to one of two paths in the
/// program, preferring goto1 in InstSplit.
</span>Split(InstSplit),
<span class="doccomment">/// EmptyLook represents a zero-width assertion in a regex program. A
/// zero-width assertion does not consume any of the input text.
</span>EmptyLook(InstEmptyLook),
<span class="doccomment">/// Char requires the regex program to match the character in InstChar at
/// the current position in the input.
</span>Char(InstChar),
<span class="doccomment">/// Ranges requires the regex program to match the character at the current
/// position in the input with one of the ranges specified in InstRanges.
</span>Ranges(InstRanges),
<span class="doccomment">/// Bytes is like Ranges, except it expresses a single byte range. It is
/// used in conjunction with Split instructions to implement multi-byte
/// character classes.
</span>Bytes(InstBytes),
}
<span class="kw">impl </span>Inst {
<span class="doccomment">/// Returns true if and only if this is a match instruction.
</span><span class="kw">pub fn </span>is_match(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; bool {
<span class="kw">match </span><span class="kw-2">*</span><span class="self">self </span>{
Inst::Match(<span class="kw">_</span>) =&gt; <span class="bool-val">true</span>,
<span class="kw">_ </span>=&gt; <span class="bool-val">false</span>,
}
}
}
<span class="doccomment">/// Representation of the Save instruction.
</span><span class="attribute">#[derive(Clone, Debug)]
</span><span class="kw">pub struct </span>InstSave {
<span class="doccomment">/// The next location to execute in the program.
</span><span class="kw">pub </span>goto: InstPtr,
<span class="doccomment">/// The capture slot (there are two slots for every capture in a regex,
/// including the zeroth capture for the entire match).
</span><span class="kw">pub </span>slot: usize,
}
<span class="doccomment">/// Representation of the Split instruction.
</span><span class="attribute">#[derive(Clone, Debug)]
</span><span class="kw">pub struct </span>InstSplit {
<span class="doccomment">/// The first instruction to try. A match resulting from following goto1
/// has precedence over a match resulting from following goto2.
</span><span class="kw">pub </span>goto1: InstPtr,
<span class="doccomment">/// The second instruction to try. A match resulting from following goto1
/// has precedence over a match resulting from following goto2.
</span><span class="kw">pub </span>goto2: InstPtr,
}
<span class="doccomment">/// Representation of the `EmptyLook` instruction.
</span><span class="attribute">#[derive(Clone, Debug)]
</span><span class="kw">pub struct </span>InstEmptyLook {
<span class="doccomment">/// The next location to execute in the program if this instruction
/// succeeds.
</span><span class="kw">pub </span>goto: InstPtr,
<span class="doccomment">/// The type of zero-width assertion to check.
</span><span class="kw">pub </span>look: EmptyLook,
}
<span class="doccomment">/// The set of zero-width match instructions.
</span><span class="attribute">#[derive(Clone, Copy, Debug, PartialEq, Eq)]
</span><span class="kw">pub enum </span>EmptyLook {
<span class="doccomment">/// Start of line or input.
</span>StartLine,
<span class="doccomment">/// End of line or input.
</span>EndLine,
<span class="doccomment">/// Start of input.
</span>StartText,
<span class="doccomment">/// End of input.
</span>EndText,
<span class="doccomment">/// Word character on one side and non-word character on other.
</span>WordBoundary,
<span class="doccomment">/// Word character on both sides or non-word character on both sides.
</span>NotWordBoundary,
<span class="doccomment">/// ASCII word boundary.
</span>WordBoundaryAscii,
<span class="doccomment">/// Not ASCII word boundary.
</span>NotWordBoundaryAscii,
}
<span class="doccomment">/// Representation of the Char instruction.
</span><span class="attribute">#[derive(Clone, Debug)]
</span><span class="kw">pub struct </span>InstChar {
<span class="doccomment">/// The next location to execute in the program if this instruction
/// succeeds.
</span><span class="kw">pub </span>goto: InstPtr,
<span class="doccomment">/// The character to test.
</span><span class="kw">pub </span>c: char,
}
<span class="doccomment">/// Representation of the Ranges instruction.
</span><span class="attribute">#[derive(Clone, Debug)]
</span><span class="kw">pub struct </span>InstRanges {
<span class="doccomment">/// The next location to execute in the program if this instruction
/// succeeds.
</span><span class="kw">pub </span>goto: InstPtr,
<span class="doccomment">/// The set of Unicode scalar value ranges to test.
</span><span class="kw">pub </span>ranges: Box&lt;[(char, char)]&gt;,
}
<span class="kw">impl </span>InstRanges {
<span class="doccomment">/// Tests whether the given input character matches this instruction.
</span><span class="kw">pub fn </span>matches(<span class="kw-2">&amp;</span><span class="self">self</span>, c: Char) -&gt; bool {
<span class="comment">// This speeds up the `match_class_unicode` benchmark by checking
// some common cases quickly without binary search. e.g., Matching
// a Unicode class on predominantly ASCII text.
</span><span class="kw">for </span>r <span class="kw">in </span><span class="self">self</span>.ranges.iter().take(<span class="number">4</span>) {
<span class="kw">if </span>c &lt; r.<span class="number">0 </span>{
<span class="kw">return </span><span class="bool-val">false</span>;
}
<span class="kw">if </span>c &lt;= r.<span class="number">1 </span>{
<span class="kw">return </span><span class="bool-val">true</span>;
}
}
<span class="self">self</span>.ranges
.binary_search_by(|r| {
<span class="kw">if </span>r.<span class="number">1 </span>&lt; c {
Ordering::Less
} <span class="kw">else if </span>r.<span class="number">0 </span>&gt; c {
Ordering::Greater
} <span class="kw">else </span>{
Ordering::Equal
}
})
.is_ok()
}
<span class="doccomment">/// Return the number of distinct characters represented by all of the
/// ranges.
</span><span class="kw">pub fn </span>num_chars(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; usize {
<span class="self">self</span>.ranges
.iter()
.map(|<span class="kw-2">&amp;</span>(s, e)| <span class="number">1 </span>+ (e <span class="kw">as </span>u32) - (s <span class="kw">as </span>u32))
.sum::&lt;u32&gt;() <span class="kw">as </span>usize
}
}
<span class="doccomment">/// Representation of the Bytes instruction.
</span><span class="attribute">#[derive(Clone, Debug)]
</span><span class="kw">pub struct </span>InstBytes {
<span class="doccomment">/// The next location to execute in the program if this instruction
/// succeeds.
</span><span class="kw">pub </span>goto: InstPtr,
<span class="doccomment">/// The start (inclusive) of this byte range.
</span><span class="kw">pub </span>start: u8,
<span class="doccomment">/// The end (inclusive) of this byte range.
</span><span class="kw">pub </span>end: u8,
}
<span class="kw">impl </span>InstBytes {
<span class="doccomment">/// Returns true if and only if the given byte is in this range.
</span><span class="kw">pub fn </span>matches(<span class="kw-2">&amp;</span><span class="self">self</span>, byte: u8) -&gt; bool {
<span class="self">self</span>.start &lt;= byte &amp;&amp; byte &lt;= <span class="self">self</span>.end
}
}
<span class="attribute">#[cfg(test)]
</span><span class="kw">mod </span>test {
<span class="attribute">#[test]
#[cfg(target_pointer_width = <span class="string">&quot;64&quot;</span>)]
</span><span class="kw">fn </span>test_size_of_inst() {
<span class="kw">use </span>std::mem::size_of;
<span class="kw">use </span><span class="kw">super</span>::Inst;
<span class="macro">assert_eq!</span>(<span class="number">32</span>, size_of::&lt;Inst&gt;());
}
}
</code></pre></div>
</section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="regex" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html>