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diff --git a/src/regex/program.rs.html b/src/regex/program.rs.html new file mode 100644 index 0000000..8f6ed02 --- /dev/null +++ b/src/regex/program.rs.html @@ -0,0 +1,1057 @@ +<!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 to the Rust file `/home/travis/.cargo/registry/src/github.com-0a35038f75765ae4/regex-0.1.38/src/program.rs`."> + <meta name="keywords" content="rust, rustlang, rust-lang"> + + <title>program.rs.html -- source</title> + + <link rel="stylesheet" type="text/css" href="../../main.css"> + + <link rel="shortcut icon" href="http://www.rust-lang.org/favicon.ico"> + +</head> +<body class="rustdoc"> + <!--[if lte IE 8]> + <div class="warning"> + This old browser is unsupported and will most likely display funky + things. + </div> + <![endif]--> + + + + <section class="sidebar"> + <a href='../../regex/index.html'><img src='http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='' width='100'></a> + + </section> + + <nav class="sub"> + <form class="search-form js-only"> + <div class="search-container"> + <input class="search-input" name="search" + autocomplete="off" + placeholder="Click or press 'S' to search, '?' for more options..." + type="search"> + </div> + </form> + </nav> + + <section id='main' class="content source"><pre class="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 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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 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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> +<span id="452">452</span> +<span id="453">453</span> +<span id="454">454</span> +<span id="455">455</span> +<span id="456">456</span> +<span id="457">457</span> +<span id="458">458</span> +<span id="459">459</span> +<span id="460">460</span> +<span id="461">461</span> +<span id="462">462</span> +<span id="463">463</span> +<span id="464">464</span> +<span id="465">465</span> +<span id="466">466</span> +<span id="467">467</span> +<span id="468">468</span> +<span id="469">469</span> +<span id="470">470</span> +<span id="471">471</span> +<span id="472">472</span> +<span id="473">473</span> +<span id="474">474</span> +<span id="475">475</span> +<span id="476">476</span> +<span id="477">477</span> +<span id="478">478</span> +<span id="479">479</span> +<span id="480">480</span> +</pre><pre class='rust '> +<span class='comment'>// Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT</span> +<span class='comment'>// file at the top-level directory of this distribution and at</span> +<span class='comment'>// http://rust-lang.org/COPYRIGHT.</span> +<span class='comment'>//</span> +<span class='comment'>// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or</span> +<span class='comment'>// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license</span> +<span class='comment'>// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your</span> +<span class='comment'>// option. This file may not be copied, modified, or distributed</span> +<span class='comment'>// except according to those terms.</span> + +<span class='kw'>use</span> <span class='ident'>std</span>::<span class='ident'>cmp</span>::{<span class='self'>self</span>, <span class='ident'>Ordering</span>}; + +<span class='kw'>use</span> <span class='ident'>syntax</span>; + +<span class='kw'>use</span> <span class='ident'>Error</span>; +<span class='kw'>use</span> <span class='ident'>backtrack</span>::{<span class='ident'>Backtrack</span>, <span class='ident'>BackMachine</span>}; +<span class='kw'>use</span> <span class='ident'>char</span>::<span class='ident'>Char</span>; +<span class='kw'>use</span> <span class='ident'>compile</span>::<span class='ident'>Compiler</span>; +<span class='kw'>use</span> <span class='ident'>nfa</span>::{<span class='ident'>Nfa</span>, <span class='ident'>NfaThreads</span>}; +<span class='kw'>use</span> <span class='ident'>pool</span>::<span class='ident'>Pool</span>; +<span class='kw'>use</span> <span class='ident'>prefix</span>::<span class='ident'>Prefix</span>; +<span class='kw'>use</span> <span class='ident'>re</span>::<span class='ident'>CaptureIdxs</span>; + +<span class='kw'>const</span> <span class='ident'>NUM_PREFIX_LIMIT</span>: <span class='ident'>usize</span> <span class='op'>=</span> <span class='number'>30</span>; +<span class='kw'>const</span> <span class='ident'>PREFIX_LENGTH_LIMIT</span>: <span class='ident'>usize</span> <span class='op'>=</span> <span class='number'>15</span>; + +<span class='kw'>pub</span> <span class='kw'>type</span> <span class='ident'>InstIdx</span> <span class='op'>=</span> <span class='ident'>usize</span>; + +<span class='doccomment'>/// An instruction, the underlying unit of a compiled regular expression</span> +<span class='attribute'>#[<span class='ident'>derive</span>(<span class='ident'>Clone</span>, <span class='ident'>Debug</span>)]</span> +<span class='kw'>pub</span> <span class='kw'>enum</span> <span class='ident'>Inst</span> { + <span class='doccomment'>/// A match has occurred.</span> + <span class='doccomment'>/// This is always the last instruction and only occurs in a single spot.</span> + <span class='doccomment'>/// We could special case this in the code, but it is much clearer to</span> + <span class='doccomment'>/// handle it as a proper instruction.</span> + <span class='ident'>Match</span>, + <span class='doccomment'>/// Save the current location in the input into the given capture location.</span> + <span class='ident'>Save</span>(<span class='ident'>usize</span>), + <span class='doccomment'>/// Jump to the instruction given.</span> + <span class='ident'>Jump</span>(<span class='ident'>InstIdx</span>), + <span class='doccomment'>/// Match either instruction, preferring the first.</span> + <span class='ident'>Split</span>(<span class='ident'>InstIdx</span>, <span class='ident'>InstIdx</span>), + <span class='doccomment'>/// A zero-width instruction. When this instruction matches, the input</span> + <span class='doccomment'>/// is not advanced.</span> + <span class='ident'>EmptyLook</span>(<span class='ident'>LookInst</span>), + <span class='doccomment'>/// Match a single possibly case insensitive character.</span> + <span class='ident'>Char</span>(<span class='ident'>OneChar</span>), + <span class='doccomment'>/// Match one or more possibly case insensitive character ranges.</span> + <span class='ident'>Ranges</span>(<span class='ident'>CharRanges</span>), +} + +<span class='doccomment'>/// A single character instruction.</span> +<span class='attribute'>#[<span class='ident'>derive</span>(<span class='ident'>Clone</span>, <span class='ident'>Debug</span>)]</span> +<span class='kw'>pub</span> <span class='kw'>struct</span> <span class='ident'>OneChar</span> { + <span class='doccomment'>/// The character.</span> + <span class='kw'>pub</span> <span class='ident'>c</span>: <span class='ident'>char</span>, + <span class='doccomment'>/// True if the character should be matched case insensitively.</span> + <span class='doccomment'>/// (i.e., The input character will need to be case folded.)</span> + <span class='kw'>pub</span> <span class='ident'>casei</span>: <span class='ident'>bool</span>, +} + +<span class='doccomment'>/// A multi-range character class instruction.</span> +<span class='attribute'>#[<span class='ident'>derive</span>(<span class='ident'>Clone</span>, <span class='ident'>Debug</span>)]</span> +<span class='kw'>pub</span> <span class='kw'>struct</span> <span class='ident'>CharRanges</span> { + <span class='doccomment'>/// Sorted sequence of non-overlapping ranges.</span> + <span class='kw'>pub</span> <span class='ident'>ranges</span>: <span class='ident'>Vec</span><span class='op'><</span>(<span class='ident'>char</span>, <span class='ident'>char</span>)<span class='op'>></span>, + <span class='doccomment'>/// Whether to match case insensitively.</span> + <span class='kw'>pub</span> <span class='ident'>casei</span>: <span class='ident'>bool</span>, +} + +<span class='doccomment'>/// The set of zero-width match instructions.</span> +<span class='attribute'>#[<span class='ident'>derive</span>(<span class='ident'>Clone</span>, <span class='ident'>Debug</span>, <span class='ident'>PartialEq</span>, <span class='ident'>Eq</span>)]</span> +<span class='kw'>pub</span> <span class='kw'>enum</span> <span class='ident'>LookInst</span> { + <span class='doccomment'>/// Start of line or input.</span> + <span class='ident'>StartLine</span>, + <span class='doccomment'>/// End of line or input.</span> + <span class='ident'>EndLine</span>, + <span class='doccomment'>/// Start of input.</span> + <span class='ident'>StartText</span>, + <span class='doccomment'>/// End of input.</span> + <span class='ident'>EndText</span>, + <span class='doccomment'>/// Word character on one side and non-word character on other.</span> + <span class='ident'>WordBoundary</span>, + <span class='doccomment'>/// Word character on both sides or non-word character on both sides.</span> + <span class='ident'>NotWordBoundary</span>, +} + +<span class='kw'>impl</span> <span class='ident'>OneChar</span> { + <span class='doccomment'>/// Tests whether the given input character matches this instruction.</span> + <span class='attribute'>#[<span class='ident'>inline</span>(<span class='ident'>always</span>)]</span> <span class='comment'>// About ~5-15% more throughput then `#[inline]`</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>matches</span>(<span class='kw-2'>&</span><span class='self'>self</span>, <span class='ident'>c</span>: <span class='ident'>Char</span>) <span class='op'>-></span> <span class='ident'>bool</span> { + <span class='self'>self</span>.<span class='ident'>c</span> <span class='op'>==</span> <span class='ident'>c</span> <span class='op'>||</span> (<span class='self'>self</span>.<span class='ident'>casei</span> <span class='op'>&&</span> <span class='self'>self</span>.<span class='ident'>c</span> <span class='op'>==</span> <span class='ident'>c</span>.<span class='ident'>case_fold</span>()) + } +} + +<span class='kw'>impl</span> <span class='ident'>CharRanges</span> { + <span class='doccomment'>/// Emits a range specifically for the `.` expression.</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>any</span>() <span class='op'>-></span> <span class='ident'>CharRanges</span> { + <span class='ident'>CharRanges</span> { + <span class='ident'>ranges</span>: <span class='macro'>vec</span><span class='macro'>!</span>[(<span class='string'>'\x00'</span>, <span class='string'>'\u{10ffff}'</span>)], + <span class='ident'>casei</span>: <span class='boolval'>false</span>, + } + } + + <span class='doccomment'>/// Emits a range specifically for the `(?s).` expression.</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>any_nonl</span>() <span class='op'>-></span> <span class='ident'>CharRanges</span> { + <span class='ident'>CharRanges</span> { + <span class='ident'>ranges</span>: <span class='macro'>vec</span><span class='macro'>!</span>[(<span class='string'>'\x00'</span>, <span class='string'>'\x09'</span>), (<span class='string'>'\x0B'</span>, <span class='string'>'\u{10ffff}'</span>)], + <span class='ident'>casei</span>: <span class='boolval'>false</span>, + } + } + + <span class='doccomment'>/// Emits a range from the AST character class.</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>from_class</span>(<span class='ident'>cls</span>: <span class='ident'>syntax</span>::<span class='ident'>CharClass</span>) <span class='op'>-></span> <span class='ident'>CharRanges</span> { + <span class='kw'>let</span> <span class='ident'>casei</span> <span class='op'>=</span> <span class='ident'>cls</span>.<span class='ident'>is_case_insensitive</span>(); + <span class='ident'>CharRanges</span> { + <span class='ident'>ranges</span>: <span class='ident'>cls</span>.<span class='ident'>into_iter</span>().<span class='ident'>map</span>(<span class='op'>|</span><span class='ident'>r</span><span class='op'>|</span> (<span class='ident'>r</span>.<span class='ident'>start</span>, <span class='ident'>r</span>.<span class='ident'>end</span>)).<span class='ident'>collect</span>(), + <span class='ident'>casei</span>: <span class='ident'>casei</span>, + } + } + + <span class='doccomment'>/// Tests whether the given input character matches this instruction.</span> + <span class='attribute'>#[<span class='ident'>inline</span>(<span class='ident'>always</span>)]</span> <span class='comment'>// About ~5-15% more throughput then `#[inline]`</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>matches</span>(<span class='kw-2'>&</span><span class='self'>self</span>, <span class='kw-2'>mut</span> <span class='ident'>c</span>: <span class='ident'>Char</span>) <span class='op'>-></span> <span class='prelude-ty'>Option</span><span class='op'><</span><span class='ident'>usize</span><span class='op'>></span> { + <span class='kw'>if</span> <span class='self'>self</span>.<span class='ident'>casei</span> { + <span class='ident'>c</span> <span class='op'>=</span> <span class='ident'>c</span>.<span class='ident'>case_fold</span>(); + } + <span class='comment'>// This speeds up the `match_class_unicode` benchmark by checking</span> + <span class='comment'>// some common cases quickly without binary search. e.g., Matching</span> + <span class='comment'>// a Unicode class on predominantly ASCII text.</span> + <span class='kw'>for</span> <span class='ident'>i</span> <span class='kw'>in</span> <span class='number'>0</span>..<span class='ident'>cmp</span>::<span class='ident'>min</span>(<span class='self'>self</span>.<span class='ident'>ranges</span>.<span class='ident'>len</span>(), <span class='number'>4</span>) { + <span class='kw'>let</span> <span class='ident'>r</span> <span class='op'>=</span> <span class='self'>self</span>.<span class='ident'>ranges</span>[<span class='ident'>i</span>]; + <span class='kw'>if</span> <span class='ident'>c</span> <span class='op'><</span> <span class='ident'>r</span>.<span class='number'>0</span> { + <span class='kw'>return</span> <span class='prelude-val'>None</span>; + } + <span class='kw'>if</span> <span class='ident'>c</span> <span class='op'><=</span> <span class='ident'>r</span>.<span class='number'>1</span> { + <span class='kw'>return</span> <span class='prelude-val'>Some</span>(<span class='ident'>i</span>); + } + } + <span class='self'>self</span>.<span class='ident'>ranges</span>.<span class='ident'>binary_search_by</span>(<span class='op'>|</span><span class='ident'>r</span><span class='op'>|</span> { + <span class='kw'>if</span> <span class='ident'>r</span>.<span class='number'>1</span> <span class='op'><</span> <span class='ident'>c</span> { + <span class='ident'>Ordering</span>::<span class='ident'>Less</span> + } <span class='kw'>else</span> <span class='kw'>if</span> <span class='ident'>r</span>.<span class='number'>0</span> <span class='op'>></span> <span class='ident'>c</span> { + <span class='ident'>Ordering</span>::<span class='ident'>Greater</span> + } <span class='kw'>else</span> { + <span class='ident'>Ordering</span>::<span class='ident'>Equal</span> + } + }).<span class='ident'>ok</span>() + } +} + +<span class='kw'>impl</span> <span class='ident'>LookInst</span> { + <span class='doccomment'>/// Tests whether the pair of characters matches this zero-width</span> + <span class='doccomment'>/// instruction.</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>matches</span>(<span class='kw-2'>&</span><span class='self'>self</span>, <span class='ident'>c1</span>: <span class='ident'>Char</span>, <span class='ident'>c2</span>: <span class='ident'>Char</span>) <span class='op'>-></span> <span class='ident'>bool</span> { + <span class='kw'>use</span> <span class='self'>self</span>::<span class='ident'>LookInst</span>::<span class='op'>*</span>; + <span class='kw'>match</span> <span class='op'>*</span><span class='self'>self</span> { + <span class='ident'>StartLine</span> <span class='op'>=></span> <span class='ident'>c1</span>.<span class='ident'>is_none</span>() <span class='op'>||</span> <span class='ident'>c1</span> <span class='op'>==</span> <span class='string'>'\n'</span>, + <span class='ident'>EndLine</span> <span class='op'>=></span> <span class='ident'>c2</span>.<span class='ident'>is_none</span>() <span class='op'>||</span> <span class='ident'>c2</span> <span class='op'>==</span> <span class='string'>'\n'</span>, + <span class='ident'>StartText</span> <span class='op'>=></span> <span class='ident'>c1</span>.<span class='ident'>is_none</span>(), + <span class='ident'>EndText</span> <span class='op'>=></span> <span class='ident'>c2</span>.<span class='ident'>is_none</span>(), + <span class='kw-2'>ref</span> <span class='ident'>wbty</span> <span class='op'>=></span> { + <span class='kw'>let</span> (<span class='ident'>w1</span>, <span class='ident'>w2</span>) <span class='op'>=</span> (<span class='ident'>c1</span>.<span class='ident'>is_word_char</span>(), <span class='ident'>c2</span>.<span class='ident'>is_word_char</span>()); + (<span class='op'>*</span><span class='ident'>wbty</span> <span class='op'>==</span> <span class='ident'>WordBoundary</span> <span class='op'>&&</span> <span class='ident'>w1</span> <span class='op'>^</span> <span class='ident'>w2</span>) + <span class='op'>||</span> (<span class='op'>*</span><span class='ident'>wbty</span> <span class='op'>==</span> <span class='ident'>NotWordBoundary</span> <span class='op'>&&</span> <span class='op'>!</span>(<span class='ident'>w1</span> <span class='op'>^</span> <span class='ident'>w2</span>)) + } + } + } +} + +<span class='doccomment'>/// The matching engines offered by this regex implementation.</span> +<span class='doccomment'>///</span> +<span class='doccomment'>/// N.B. This is exported for use in testing.</span> +<span class='attribute'>#[<span class='ident'>doc</span>(<span class='ident'>hidden</span>)]</span> +<span class='attribute'>#[<span class='ident'>derive</span>(<span class='ident'>Clone</span>, <span class='ident'>Copy</span>, <span class='ident'>Debug</span>)]</span> +<span class='kw'>pub</span> <span class='kw'>enum</span> <span class='ident'>MatchEngine</span> { + <span class='doccomment'>/// A bounded backtracking implementation. About twice as fast as the</span> + <span class='doccomment'>/// NFA, but can only work on small regexes and small input.</span> + <span class='ident'>Backtrack</span>, + <span class='doccomment'>/// A full NFA simulation. Can always be employed but almost always the</span> + <span class='doccomment'>/// slowest choice.</span> + <span class='ident'>Nfa</span>, + <span class='doccomment'>/// If the entire regex is a literal and no capture groups have been</span> + <span class='doccomment'>/// requested, then we can degrade to a simple substring match.</span> + <span class='ident'>Literals</span>, +} + +<span class='doccomment'>/// Program represents a compiled regular expression. Once an expression is</span> +<span class='doccomment'>/// compiled, its representation is immutable and will never change.</span> +<span class='doccomment'>/// (Well, almost. In fact, the matching engines cache state that can be</span> +<span class='doccomment'>/// reused on subsequent searches. But this is interior mutability that</span> +<span class='doccomment'>/// shouldn't be observable by the caller.)</span> +<span class='attribute'>#[<span class='ident'>derive</span>(<span class='ident'>Debug</span>)]</span> +<span class='kw'>pub</span> <span class='kw'>struct</span> <span class='ident'>Program</span> { + <span class='doccomment'>/// The original regular expression string.</span> + <span class='kw'>pub</span> <span class='ident'>original</span>: <span class='ident'>String</span>, + <span class='doccomment'>/// A sequence of instructions.</span> + <span class='kw'>pub</span> <span class='ident'>insts</span>: <span class='ident'>Vec</span><span class='op'><</span><span class='ident'>Inst</span><span class='op'>></span>, + <span class='doccomment'>/// The sequence of capture group names. There is an entry for each capture</span> + <span class='doccomment'>/// group index and a name exists only if the capture group is named.</span> + <span class='kw'>pub</span> <span class='ident'>cap_names</span>: <span class='ident'>Vec</span><span class='op'><</span><span class='prelude-ty'>Option</span><span class='op'><</span><span class='ident'>String</span><span class='op'>>></span>, + <span class='doccomment'>/// If the regular expression requires a literal prefix in order to have a</span> + <span class='doccomment'>/// match, that prefix is stored here as a DFA.</span> + <span class='kw'>pub</span> <span class='ident'>prefixes</span>: <span class='ident'>Prefix</span>, + <span class='doccomment'>/// True iff matching any literal prefix indicates a match.</span> + <span class='kw'>pub</span> <span class='ident'>prefixes_complete</span>: <span class='ident'>bool</span>, + <span class='doccomment'>/// True iff program is anchored at the beginning.</span> + <span class='kw'>pub</span> <span class='ident'>anchored_begin</span>: <span class='ident'>bool</span>, + <span class='doccomment'>/// True iff program is anchored at the end.</span> + <span class='kw'>pub</span> <span class='ident'>anchored_end</span>: <span class='ident'>bool</span>, + <span class='doccomment'>/// The type of matching engine to use.</span> + <span class='doccomment'>/// When `None` (the default), pick an engine automatically.</span> + <span class='kw'>pub</span> <span class='ident'>engine</span>: <span class='prelude-ty'>Option</span><span class='op'><</span><span class='ident'>MatchEngine</span><span class='op'>></span>, + <span class='doccomment'>/// Cached NFA threads.</span> + <span class='kw'>pub</span> <span class='ident'>nfa_threads</span>: <span class='ident'>Pool</span><span class='op'><</span><span class='ident'>NfaThreads</span><span class='op'>></span>, + <span class='doccomment'>/// Cached backtracking memory.</span> + <span class='kw'>pub</span> <span class='ident'>backtrack</span>: <span class='ident'>Pool</span><span class='op'><</span><span class='ident'>BackMachine</span><span class='op'>></span>, +} + +<span class='kw'>impl</span> <span class='ident'>Program</span> { + <span class='doccomment'>/// Compiles a Regex.</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>new</span>( + <span class='ident'>engine</span>: <span class='prelude-ty'>Option</span><span class='op'><</span><span class='ident'>MatchEngine</span><span class='op'>></span>, + <span class='ident'>size_limit</span>: <span class='ident'>usize</span>, + <span class='ident'>re</span>: <span class='kw-2'>&</span><span class='ident'>str</span>, + ) <span class='op'>-></span> <span class='prelude-ty'>Result</span><span class='op'><</span><span class='ident'>Program</span>, <span class='ident'>Error</span><span class='op'>></span> { + <span class='kw'>let</span> <span class='ident'>expr</span> <span class='op'>=</span> <span class='macro'>try</span><span class='macro'>!</span>(<span class='ident'>syntax</span>::<span class='ident'>Expr</span>::<span class='ident'>parse</span>(<span class='ident'>re</span>)); + <span class='kw'>let</span> (<span class='ident'>insts</span>, <span class='ident'>cap_names</span>) <span class='op'>=</span> <span class='macro'>try</span><span class='macro'>!</span>(<span class='ident'>Compiler</span>::<span class='ident'>new</span>(<span class='ident'>size_limit</span>).<span class='ident'>compile</span>(<span class='ident'>expr</span>)); + <span class='kw'>let</span> (<span class='ident'>insts_len</span>, <span class='ident'>ncaps</span>) <span class='op'>=</span> (<span class='ident'>insts</span>.<span class='ident'>len</span>(), <span class='ident'>num_captures</span>(<span class='kw-2'>&</span><span class='ident'>insts</span>)); + <span class='kw'>let</span> <span class='ident'>create_threads</span> <span class='op'>=</span> <span class='kw'>move</span> <span class='op'>||</span> <span class='ident'>NfaThreads</span>::<span class='ident'>new</span>(<span class='ident'>insts_len</span>, <span class='ident'>ncaps</span>); + <span class='kw'>let</span> <span class='ident'>create_backtrack</span> <span class='op'>=</span> <span class='kw'>move</span> <span class='op'>||</span> <span class='ident'>BackMachine</span>::<span class='ident'>new</span>(); + <span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>prog</span> <span class='op'>=</span> <span class='ident'>Program</span> { + <span class='ident'>original</span>: <span class='ident'>re</span>.<span class='ident'>into</span>(), + <span class='ident'>insts</span>: <span class='ident'>insts</span>, + <span class='ident'>cap_names</span>: <span class='ident'>cap_names</span>, + <span class='ident'>prefixes</span>: <span class='ident'>Prefix</span>::<span class='ident'>Empty</span>, + <span class='ident'>prefixes_complete</span>: <span class='boolval'>false</span>, + <span class='ident'>anchored_begin</span>: <span class='boolval'>false</span>, + <span class='ident'>anchored_end</span>: <span class='boolval'>false</span>, + <span class='ident'>engine</span>: <span class='ident'>engine</span>, + <span class='ident'>nfa_threads</span>: <span class='ident'>Pool</span>::<span class='ident'>new</span>(<span class='ident'>Box</span>::<span class='ident'>new</span>(<span class='ident'>create_threads</span>)), + <span class='ident'>backtrack</span>: <span class='ident'>Pool</span>::<span class='ident'>new</span>(<span class='ident'>Box</span>::<span class='ident'>new</span>(<span class='ident'>create_backtrack</span>)), + }; + + <span class='ident'>prog</span>.<span class='ident'>find_prefixes</span>(); + <span class='ident'>prog</span>.<span class='ident'>anchored_begin</span> <span class='op'>=</span> <span class='kw'>match</span> <span class='ident'>prog</span>.<span class='ident'>insts</span>[<span class='number'>1</span>] { + <span class='ident'>Inst</span>::<span class='ident'>EmptyLook</span>(<span class='ident'>LookInst</span>::<span class='ident'>StartText</span>) <span class='op'>=></span> <span class='boolval'>true</span>, + _ <span class='op'>=></span> <span class='boolval'>false</span>, + }; + <span class='ident'>prog</span>.<span class='ident'>anchored_end</span> <span class='op'>=</span> <span class='kw'>match</span> <span class='ident'>prog</span>.<span class='ident'>insts</span>[<span class='ident'>prog</span>.<span class='ident'>insts</span>.<span class='ident'>len</span>() <span class='op'>-</span> <span class='number'>3</span>] { + <span class='ident'>Inst</span>::<span class='ident'>EmptyLook</span>(<span class='ident'>LookInst</span>::<span class='ident'>EndText</span>) <span class='op'>=></span> <span class='boolval'>true</span>, + _ <span class='op'>=></span> <span class='boolval'>false</span>, + }; + <span class='prelude-val'>Ok</span>(<span class='ident'>prog</span>) + } + + <span class='doccomment'>/// Executes a compiled regex program.</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>exec</span>( + <span class='kw-2'>&</span><span class='self'>self</span>, + <span class='ident'>caps</span>: <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>CaptureIdxs</span>, + <span class='ident'>text</span>: <span class='kw-2'>&</span><span class='ident'>str</span>, + <span class='ident'>start</span>: <span class='ident'>usize</span>, + ) <span class='op'>-></span> <span class='ident'>bool</span> { + <span class='kw'>match</span> <span class='self'>self</span>.<span class='ident'>choose_engine</span>(<span class='ident'>caps</span>.<span class='ident'>len</span>(), <span class='ident'>text</span>) { + <span class='ident'>MatchEngine</span>::<span class='ident'>Backtrack</span> <span class='op'>=></span> <span class='ident'>Backtrack</span>::<span class='ident'>exec</span>(<span class='self'>self</span>, <span class='ident'>caps</span>, <span class='ident'>text</span>, <span class='ident'>start</span>), + <span class='ident'>MatchEngine</span>::<span class='ident'>Nfa</span> <span class='op'>=></span> <span class='ident'>Nfa</span>::<span class='ident'>exec</span>(<span class='self'>self</span>, <span class='ident'>caps</span>, <span class='ident'>text</span>, <span class='ident'>start</span>), + <span class='ident'>MatchEngine</span>::<span class='ident'>Literals</span> <span class='op'>=></span> { + <span class='kw'>match</span> <span class='self'>self</span>.<span class='ident'>prefixes</span>.<span class='ident'>find</span>(<span class='kw-2'>&</span><span class='ident'>text</span>[<span class='ident'>start</span>..]) { + <span class='prelude-val'>None</span> <span class='op'>=></span> <span class='boolval'>false</span>, + <span class='prelude-val'>Some</span>((<span class='ident'>s</span>, <span class='ident'>e</span>)) <span class='op'>=></span> { + <span class='kw'>if</span> <span class='ident'>caps</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>2</span> { + <span class='ident'>caps</span>[<span class='number'>0</span>] <span class='op'>=</span> <span class='prelude-val'>Some</span>(<span class='ident'>start</span> <span class='op'>+</span> <span class='ident'>s</span>); + <span class='ident'>caps</span>[<span class='number'>1</span>] <span class='op'>=</span> <span class='prelude-val'>Some</span>(<span class='ident'>start</span> <span class='op'>+</span> <span class='ident'>e</span>); + } + <span class='boolval'>true</span> + } + } + } + } + } + + <span class='kw'>fn</span> <span class='ident'>choose_engine</span>(<span class='kw-2'>&</span><span class='self'>self</span>, <span class='ident'>cap_len</span>: <span class='ident'>usize</span>, <span class='ident'>text</span>: <span class='kw-2'>&</span><span class='ident'>str</span>) <span class='op'>-></span> <span class='ident'>MatchEngine</span> { + <span class='comment'>// If the engine is already chosen, then we use it.</span> + <span class='comment'>// But that might not be a good idea. e.g., What if `Literals` is</span> + <span class='comment'>// chosen and it can't work? I guess we should probably check whether</span> + <span class='comment'>// the chosen engine is appropriate or not.</span> + <span class='self'>self</span>.<span class='ident'>engine</span>.<span class='ident'>unwrap_or_else</span>(<span class='op'>||</span> { + <span class='kw'>if</span> <span class='ident'>cap_len</span> <span class='op'><=</span> <span class='number'>2</span> + <span class='op'>&&</span> <span class='self'>self</span>.<span class='ident'>prefixes</span>.<span class='ident'>preserves_priority</span>() + <span class='op'>&&</span> <span class='self'>self</span>.<span class='ident'>prefixes_complete</span> { + <span class='ident'>MatchEngine</span>::<span class='ident'>Literals</span> + } <span class='kw'>else</span> <span class='kw'>if</span> <span class='ident'>Backtrack</span>::<span class='ident'>should_exec</span>(<span class='self'>self</span>, <span class='ident'>text</span>) { + <span class='comment'>// We're only here if the input and regex combined are small.</span> + <span class='ident'>MatchEngine</span>::<span class='ident'>Backtrack</span> + } <span class='kw'>else</span> { + <span class='ident'>MatchEngine</span>::<span class='ident'>Nfa</span> + } + }) + } + + <span class='doccomment'>/// Returns the total number of capture groups in the regular expression.</span> + <span class='doccomment'>/// This includes the zeroth capture.</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>num_captures</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>usize</span> { + <span class='ident'>num_captures</span>(<span class='kw-2'>&</span><span class='self'>self</span>.<span class='ident'>insts</span>) + } + + <span class='doccomment'>/// Allocate new capture groups.</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>alloc_captures</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>Vec</span><span class='op'><</span><span class='prelude-ty'>Option</span><span class='op'><</span><span class='ident'>usize</span><span class='op'>>></span> { + <span class='macro'>vec</span><span class='macro'>!</span>[<span class='prelude-val'>None</span>; <span class='number'>2</span> <span class='op'>*</span> <span class='self'>self</span>.<span class='ident'>num_captures</span>()] + } + + <span class='doccomment'>/// Find and store a prefix machine for the current program.</span> + <span class='kw'>pub</span> <span class='kw'>fn</span> <span class='ident'>find_prefixes</span>(<span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='self'>self</span>) { + <span class='kw'>use</span> <span class='self'>self</span>::<span class='ident'>Inst</span>::<span class='op'>*</span>; + + <span class='kw'>let</span> (<span class='ident'>ps</span>, <span class='ident'>complete</span>) <span class='op'>=</span> <span class='self'>self</span>.<span class='ident'>prefixes_from_insts</span>(<span class='number'>1</span>); + <span class='kw'>if</span> <span class='ident'>ps</span>.<span class='ident'>len</span>() <span class='op'>></span> <span class='number'>0</span> { + <span class='self'>self</span>.<span class='ident'>prefixes</span> <span class='op'>=</span> <span class='ident'>Prefix</span>::<span class='ident'>new</span>(<span class='ident'>ps</span>); + <span class='self'>self</span>.<span class='ident'>prefixes_complete</span> <span class='op'>=</span> <span class='ident'>complete</span>; + <span class='kw'>return</span>; + } + <span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>pc</span> <span class='op'>=</span> <span class='number'>1</span>; + <span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>prefixes</span> <span class='op'>=</span> <span class='macro'>vec</span><span class='macro'>!</span>[]; + <span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>pcomplete</span> <span class='op'>=</span> <span class='boolval'>true</span>; + <span class='kw'>while</span> <span class='kw'>let</span> <span class='ident'>Split</span>(<span class='ident'>x</span>, <span class='ident'>y</span>) <span class='op'>=</span> <span class='self'>self</span>.<span class='ident'>insts</span>[<span class='ident'>pc</span>] { + <span class='kw'>let</span> (<span class='ident'>xps</span>, <span class='ident'>xcomplete</span>) <span class='op'>=</span> <span class='self'>self</span>.<span class='ident'>prefixes_from_insts</span>(<span class='ident'>x</span>); + <span class='kw'>let</span> (<span class='ident'>yps</span>, <span class='ident'>ycomplete</span>) <span class='op'>=</span> <span class='self'>self</span>.<span class='ident'>prefixes_from_insts</span>(<span class='ident'>y</span>); + <span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>done</span> <span class='op'>=</span> <span class='boolval'>false</span>; + <span class='kw'>match</span> (<span class='kw-2'>&</span><span class='self'>self</span>.<span class='ident'>insts</span>[<span class='ident'>x</span>], <span class='kw-2'>&</span><span class='self'>self</span>.<span class='ident'>insts</span>[<span class='ident'>y</span>]) { + <span class='comment'>// We should be able to support this. Add explicit stack. ---AG</span> + (<span class='kw-2'>&</span><span class='ident'>Split</span>(_, _), <span class='kw-2'>&</span><span class='ident'>Split</span>(_, _)) <span class='op'>=></span> <span class='kw'>return</span>, + (_, <span class='kw-2'>&</span><span class='ident'>Split</span>(_, _)) <span class='kw'>if</span> <span class='ident'>xps</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>0</span> <span class='op'>=></span> <span class='kw'>return</span>, + (_, <span class='kw-2'>&</span><span class='ident'>Split</span>(_, _)) <span class='op'>=></span> { + <span class='ident'>pcomplete</span> <span class='op'>=</span> <span class='ident'>pcomplete</span> <span class='op'>&&</span> <span class='ident'>xcomplete</span>; + <span class='ident'>prefixes</span>.<span class='ident'>extend</span>(<span class='ident'>xps</span>); + <span class='ident'>pc</span> <span class='op'>=</span> <span class='ident'>y</span>; + } + (<span class='kw-2'>&</span><span class='ident'>Split</span>(_, _), _) <span class='kw'>if</span> <span class='ident'>yps</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>0</span> <span class='op'>=></span> <span class='kw'>return</span>, + (<span class='kw-2'>&</span><span class='ident'>Split</span>(_, _), _) <span class='op'>=></span> { + <span class='ident'>pcomplete</span> <span class='op'>=</span> <span class='ident'>pcomplete</span> <span class='op'>&&</span> <span class='ident'>ycomplete</span>; + <span class='ident'>prefixes</span>.<span class='ident'>extend</span>(<span class='ident'>yps</span>); + <span class='ident'>pc</span> <span class='op'>=</span> <span class='ident'>x</span>; + } + _ <span class='kw'>if</span> <span class='ident'>xps</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>0</span> <span class='op'>||</span> <span class='ident'>yps</span>.<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>0</span> <span class='op'>=></span> <span class='kw'>return</span>, + <span class='comment'>// This is our base case. We've followed splits the whole</span> + <span class='comment'>// way, which means both instructions lead to a match.</span> + _ <span class='op'>=></span> { + <span class='ident'>pcomplete</span> <span class='op'>=</span> <span class='ident'>pcomplete</span> <span class='op'>&&</span> <span class='ident'>xcomplete</span> <span class='op'>&&</span> <span class='ident'>ycomplete</span>; + <span class='ident'>prefixes</span>.<span class='ident'>extend</span>(<span class='ident'>xps</span>); + <span class='ident'>prefixes</span>.<span class='ident'>extend</span>(<span class='ident'>yps</span>); + <span class='ident'>done</span> <span class='op'>=</span> <span class='boolval'>true</span>; + } + } + <span class='comment'>// Arg. We've over-extended ourselves, quit with nothing to</span> + <span class='comment'>// show for it.</span> + <span class='kw'>if</span> <span class='ident'>prefixes</span>.<span class='ident'>len</span>() <span class='op'>></span> <span class='ident'>NUM_PREFIX_LIMIT</span> { + <span class='kw'>return</span>; + } + <span class='kw'>if</span> <span class='ident'>done</span> { <span class='kw'>break</span>; } + } + <span class='self'>self</span>.<span class='ident'>prefixes</span> <span class='op'>=</span> <span class='ident'>Prefix</span>::<span class='ident'>new</span>(<span class='ident'>prefixes</span>); + <span class='self'>self</span>.<span class='ident'>prefixes_complete</span> <span class='op'>=</span> <span class='ident'>pcomplete</span> <span class='op'>&&</span> <span class='self'>self</span>.<span class='ident'>prefixes</span>.<span class='ident'>len</span>() <span class='op'>></span> <span class='number'>0</span>; + } + + <span class='doccomment'>/// Find a prefix starting at the given instruction.</span> + <span class='doccomment'>///</span> + <span class='doccomment'>/// Returns `true` in the tuple if the end of the prefix leads trivially</span> + <span class='doccomment'>/// to a match. (This may report false negatives, but being conservative</span> + <span class='doccomment'>/// is OK.)</span> + <span class='kw'>fn</span> <span class='ident'>prefixes_from_insts</span>(<span class='kw-2'>&</span><span class='self'>self</span>, <span class='kw-2'>mut</span> <span class='ident'>pc</span>: <span class='ident'>usize</span>) <span class='op'>-></span> (<span class='ident'>Vec</span><span class='op'><</span><span class='ident'>String</span><span class='op'>></span>, <span class='ident'>bool</span>) { + <span class='kw'>use</span> <span class='self'>self</span>::<span class='ident'>Inst</span>::<span class='op'>*</span>; + + <span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>complete</span> <span class='op'>=</span> <span class='boolval'>true</span>; + <span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>alts</span> <span class='op'>=</span> <span class='macro'>vec</span><span class='macro'>!</span>[<span class='ident'>String</span>::<span class='ident'>new</span>()]; + <span class='kw'>while</span> <span class='ident'>pc</span> <span class='op'><</span> <span class='self'>self</span>.<span class='ident'>insts</span>.<span class='ident'>len</span>() { + <span class='kw'>let</span> <span class='ident'>inst</span> <span class='op'>=</span> <span class='kw-2'>&</span><span class='self'>self</span>.<span class='ident'>insts</span>[<span class='ident'>pc</span>]; + + <span class='comment'>// Each iteration adds one character to every alternate prefix *or*</span> + <span class='comment'>// it stops. Thus, the prefix alternates grow in lock step, and it</span> + <span class='comment'>// suffices to check one of them to see if the prefix limit has been</span> + <span class='comment'>// exceeded.</span> + <span class='kw'>if</span> <span class='ident'>alts</span>[<span class='number'>0</span>].<span class='ident'>len</span>() <span class='op'>></span> <span class='ident'>PREFIX_LENGTH_LIMIT</span> { + <span class='ident'>complete</span> <span class='op'>=</span> <span class='boolval'>false</span>; + <span class='kw'>break</span>; + } + <span class='kw'>match</span> <span class='op'>*</span><span class='ident'>inst</span> { + <span class='ident'>Save</span>(_) <span class='op'>=></span> { <span class='ident'>pc</span> <span class='op'>+=</span> <span class='number'>1</span>; <span class='kw'>continue</span> } <span class='comment'>// completely ignore it</span> + <span class='ident'>Char</span>(<span class='ident'>OneChar</span> { <span class='ident'>c</span>, <span class='ident'>casei</span>: <span class='boolval'>false</span> }) <span class='op'>=></span> { + <span class='kw'>for</span> <span class='ident'>alt</span> <span class='kw'>in</span> <span class='kw-2'>&</span><span class='kw-2'>mut</span> <span class='ident'>alts</span> { + <span class='ident'>alt</span>.<span class='ident'>push</span>(<span class='ident'>c</span>); + } + <span class='ident'>pc</span> <span class='op'>+=</span> <span class='number'>1</span>; + } + <span class='ident'>Ranges</span>(<span class='ident'>CharRanges</span> { <span class='kw-2'>ref</span> <span class='ident'>ranges</span>, <span class='ident'>casei</span>: <span class='boolval'>false</span> }) <span class='op'>=></span> { + <span class='kw'>let</span> <span class='ident'>nchars</span> <span class='op'>=</span> <span class='ident'>num_chars_in_ranges</span>(<span class='ident'>ranges</span>); + <span class='kw'>if</span> <span class='ident'>alts</span>.<span class='ident'>len</span>() <span class='op'>*</span> <span class='ident'>nchars</span> <span class='op'>></span> <span class='ident'>NUM_PREFIX_LIMIT</span> { + <span class='ident'>complete</span> <span class='op'>=</span> <span class='boolval'>false</span>; + <span class='kw'>break</span>; + } + + <span class='kw'>let</span> <span class='ident'>orig</span> <span class='op'>=</span> <span class='ident'>alts</span>; + <span class='ident'>alts</span> <span class='op'>=</span> <span class='ident'>Vec</span>::<span class='ident'>with_capacity</span>(<span class='ident'>orig</span>.<span class='ident'>len</span>()); + <span class='kw'>for</span> <span class='kw-2'>&</span>(<span class='ident'>s</span>, <span class='ident'>e</span>) <span class='kw'>in</span> <span class='ident'>ranges</span> { + <span class='kw'>for</span> <span class='ident'>c</span> <span class='kw'>in</span> (<span class='ident'>s</span> <span class='kw'>as</span> <span class='ident'>u32</span>)..(<span class='ident'>e</span> <span class='kw'>as</span> <span class='ident'>u32</span> <span class='op'>+</span> <span class='number'>1</span>){ + <span class='kw'>for</span> <span class='ident'>alt</span> <span class='kw'>in</span> <span class='kw-2'>&</span><span class='ident'>orig</span> { + <span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>alt</span> <span class='op'>=</span> <span class='ident'>alt</span>.<span class='ident'>clone</span>(); + <span class='ident'>alt</span>.<span class='ident'>push</span>(::<span class='ident'>std</span>::<span class='ident'>char</span>::<span class='ident'>from_u32</span>(<span class='ident'>c</span>).<span class='ident'>unwrap</span>()); + <span class='ident'>alts</span>.<span class='ident'>push</span>(<span class='ident'>alt</span>); + } + } + } + <span class='ident'>pc</span> <span class='op'>+=</span> <span class='number'>1</span>; + } + <span class='ident'>Jump</span>(<span class='ident'>pc2</span>) <span class='op'>=></span> <span class='ident'>pc</span> <span class='op'>=</span> <span class='ident'>pc2</span>, + _ <span class='op'>=></span> { <span class='ident'>complete</span> <span class='op'>=</span> <span class='self'>self</span>.<span class='ident'>leads_to_match</span>(<span class='ident'>pc</span>); <span class='kw'>break</span> } + } + } + <span class='kw'>if</span> <span class='ident'>alts</span>[<span class='number'>0</span>].<span class='ident'>len</span>() <span class='op'>==</span> <span class='number'>0</span> { + (<span class='macro'>vec</span><span class='macro'>!</span>[], <span class='boolval'>false</span>) + } <span class='kw'>else</span> { + (<span class='ident'>alts</span>, <span class='ident'>complete</span>) + } + } + + <span class='kw'>fn</span> <span class='ident'>leads_to_match</span>(<span class='kw-2'>&</span><span class='self'>self</span>, <span class='kw-2'>mut</span> <span class='ident'>pc</span>: <span class='ident'>usize</span>) <span class='op'>-></span> <span class='ident'>bool</span> { + <span class='comment'>// I'm pretty sure this is conservative, so it might have some</span> + <span class='comment'>// false negatives.</span> + <span class='kw'>loop</span> { + <span class='kw'>match</span> <span class='self'>self</span>.<span class='ident'>insts</span>[<span class='ident'>pc</span>] { + <span class='ident'>Inst</span>::<span class='ident'>Match</span> <span class='op'>=></span> <span class='kw'>return</span> <span class='boolval'>true</span>, + <span class='ident'>Inst</span>::<span class='ident'>Save</span>(_) <span class='op'>=></span> <span class='ident'>pc</span> <span class='op'>+=</span> <span class='number'>1</span>, + <span class='ident'>Inst</span>::<span class='ident'>Jump</span>(<span class='ident'>pc2</span>) <span class='op'>=></span> <span class='ident'>pc</span> <span class='op'>=</span> <span class='ident'>pc2</span>, + _ <span class='op'>=></span> <span class='kw'>return</span> <span class='boolval'>false</span>, + } + } + } +} + +<span class='kw'>impl</span> <span class='ident'>Clone</span> <span class='kw'>for</span> <span class='ident'>Program</span> { + <span class='kw'>fn</span> <span class='ident'>clone</span>(<span class='kw-2'>&</span><span class='self'>self</span>) <span class='op'>-></span> <span class='ident'>Program</span> { + <span class='kw'>let</span> (<span class='ident'>insts_len</span>, <span class='ident'>ncaps</span>) <span class='op'>=</span> (<span class='self'>self</span>.<span class='ident'>insts</span>.<span class='ident'>len</span>(), <span class='self'>self</span>.<span class='ident'>num_captures</span>()); + <span class='kw'>let</span> <span class='ident'>create_threads</span> <span class='op'>=</span> <span class='kw'>move</span> <span class='op'>||</span> <span class='ident'>NfaThreads</span>::<span class='ident'>new</span>(<span class='ident'>insts_len</span>, <span class='ident'>ncaps</span>); + <span class='kw'>let</span> <span class='ident'>create_backtrack</span> <span class='op'>=</span> <span class='kw'>move</span> <span class='op'>||</span> <span class='ident'>BackMachine</span>::<span class='ident'>new</span>(); + <span class='ident'>Program</span> { + <span class='ident'>original</span>: <span class='self'>self</span>.<span class='ident'>original</span>.<span class='ident'>clone</span>(), + <span class='ident'>insts</span>: <span class='self'>self</span>.<span class='ident'>insts</span>.<span class='ident'>clone</span>(), + <span class='ident'>cap_names</span>: <span class='self'>self</span>.<span class='ident'>cap_names</span>.<span class='ident'>clone</span>(), + <span class='ident'>prefixes</span>: <span class='self'>self</span>.<span class='ident'>prefixes</span>.<span class='ident'>clone</span>(), + <span class='ident'>prefixes_complete</span>: <span class='self'>self</span>.<span class='ident'>prefixes_complete</span>, + <span class='ident'>anchored_begin</span>: <span class='self'>self</span>.<span class='ident'>anchored_begin</span>, + <span class='ident'>anchored_end</span>: <span class='self'>self</span>.<span class='ident'>anchored_end</span>, + <span class='ident'>engine</span>: <span class='self'>self</span>.<span class='ident'>engine</span>, + <span class='ident'>nfa_threads</span>: <span class='ident'>Pool</span>::<span class='ident'>new</span>(<span class='ident'>Box</span>::<span class='ident'>new</span>(<span class='ident'>create_threads</span>)), + <span class='ident'>backtrack</span>: <span class='ident'>Pool</span>::<span class='ident'>new</span>(<span class='ident'>Box</span>::<span class='ident'>new</span>(<span class='ident'>create_backtrack</span>)), + } + } +} + +<span class='doccomment'>/// Return the number of captures in the given sequence of instructions.</span> +<span class='kw'>fn</span> <span class='ident'>num_captures</span>(<span class='ident'>insts</span>: <span class='kw-2'>&</span>[<span class='ident'>Inst</span>]) <span class='op'>-></span> <span class='ident'>usize</span> { + <span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>n</span> <span class='op'>=</span> <span class='number'>0</span>; + <span class='kw'>for</span> <span class='ident'>inst</span> <span class='kw'>in</span> <span class='ident'>insts</span> { + <span class='kw'>match</span> <span class='op'>*</span><span class='ident'>inst</span> { + <span class='ident'>Inst</span>::<span class='ident'>Save</span>(<span class='ident'>c</span>) <span class='op'>=></span> <span class='ident'>n</span> <span class='op'>=</span> <span class='ident'>cmp</span>::<span class='ident'>max</span>(<span class='ident'>n</span>, <span class='ident'>c</span><span class='op'>+</span><span class='number'>1</span>), + _ <span class='op'>=></span> {} + } + } + <span class='comment'>// There's exactly 2 Save slots for every capture.</span> + <span class='ident'>n</span> <span class='op'>/</span> <span class='number'>2</span> +} + +<span class='doccomment'>/// Count the number of characters in the given range.</span> +<span class='doccomment'>///</span> +<span class='doccomment'>/// This is useful for pre-emptively limiting the number of prefix literals</span> +<span class='doccomment'>/// we extract from a regex program.</span> +<span class='kw'>fn</span> <span class='ident'>num_chars_in_ranges</span>(<span class='ident'>ranges</span>: <span class='kw-2'>&</span>[(<span class='ident'>char</span>, <span class='ident'>char</span>)]) <span class='op'>-></span> <span class='ident'>usize</span> { + <span class='ident'>ranges</span>.<span class='ident'>iter</span>() + .<span class='ident'>map</span>(<span class='op'>|</span><span class='kw-2'>&</span>(<span class='ident'>s</span>, <span class='ident'>e</span>)<span class='op'>|</span> (<span class='ident'>e</span> <span class='kw'>as</span> <span class='ident'>u32</span>) <span class='op'>-</span> (<span class='ident'>s</span> <span class='kw'>as</span> <span class='ident'>u32</span>)) + .<span class='ident'>fold</span>(<span class='number'>0</span>, <span class='op'>|</span><span class='ident'>acc</span>, <span class='ident'>len</span><span class='op'>|</span> <span class='ident'>acc</span> <span class='op'>+</span> <span class='ident'>len</span>) <span class='kw'>as</span> <span class='ident'>usize</span> +} +</pre> +</section> + <section id='search' class="content hidden"></section> + + <section class="footer"></section> + + <div id="help" class="hidden"> + <div class="shortcuts"> + <h1>Keyboard shortcuts</h1> + <dl> + <dt>?</dt> + <dd>Show this help dialog</dd> + <dt>S</dt> + <dd>Focus the search field</dd> + <dt>⇤</dt> + <dd>Move up in search results</dd> + <dt>⇥</dt> + <dd>Move down in search results</dd> + <dt>⏎</dt> + <dd>Go to active search result</dd> + </dl> + </div> + <div class="infos"> + <h1>Search tricks</h1> + <p> + Prefix searches with a type followed by a colon (e.g. + <code>fn:</code>) to restrict the search to a given type. + </p> + <p> + Accepted types are: <code>fn</code>, <code>mod</code>, + <code>struct</code>, <code>enum</code>, + <code>trait</code>, <code>typedef</code> (or + <code>tdef</code>). + </p> + <p> + Search functions by type signature (e.g. + <code>vec -> usize</code>) + </p> + </div> + </div> + + + + <script> + window.rootPath = "../../"; + window.currentCrate = "regex"; + window.playgroundUrl = ""; + </script> + <script src="../../jquery.js"></script> + <script src="../../main.js"></script> + + <script async src="../../search-index.js"></script> +</body> +</html>
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