boost-react-native-bundle

<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Appendices</title> <link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> <link rel="up" href="../xpressive.html" title="Chapter 39. Boost.Xpressive"> <link rel="prev" href="../boost_xpressive/acknowledgments.html" title="Acknowledgments"> <link rel="next" href="../tools.html" title="Part II. Boost Tools"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> <td align="center"><a href="../../../index.html">Home</a></td> <td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="../boost_xpressive/acknowledgments.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../xpressive.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../tools.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> <a name="xpressive.appendices"></a><a class="link" href="appendices.html" title="Appendices">Appendices</a> </h2></div></div></div> <div class="toc"><dl class="toc"> <dt><span class="section"><a href="appendices.html#boost_xpressive.appendices.appendix_1__history">Appendix 1: History</a></span></dt> <dt><span class="section"><a href="appendices.html#boost_xpressive.appendices.appendix_2__not_yet_implemented">Appendix 2: Not Yet Implemented</a></span></dt> <dt><span class="section"><a href="appendices.html#boost_xpressive.appendices.appendix_3__differences_from_boost_regex">Appendix 3: Differences from Boost.Regex</a></span></dt> <dt><span class="section"><a href="appendices.html#boost_xpressive.appendices.perf">Appendix 4: Performance Comparison</a></span></dt> <dt><span class="section"><a href="appendices.html#xpressive.appendices.appendix_5__implementation_notes">Appendix 5: Implementation Notes</a></span></dt> </dl></div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_xpressive.appendices.appendix_1__history"></a><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history" title="Appendix 1: History">Appendix 1: History</a> </h3></div></div></div> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h0"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_2_1_0_6_12_2008"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_2_1_0_6_12_2008">Version 2.1.0 6/12/2008</a> </h3> <p> New Features: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> <li class="listitem"> <code class="computeroutput"><span class="identifier">skip</span><span class="special">()</span></code> primitive for static regexes, which allows you to specify parts of the input string to ignore during regex matching. </li> <li class="listitem"> Range-based <code class="computeroutput"><span class="identifier">regex_replace</span><span class="special">()</span></code> algorithm interface. </li> <li class="listitem"> <code class="computeroutput"><span class="identifier">regex_replace</span><span class="special">()</span></code> accepts formatter objects and formatter lambda expressions in addition to format strings. </li> </ul></div> <p> Bugs Fixed: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> Semantic actions in look-aheads, look-behinds and independent sub-expressions execute eagerly instead of causing a crash. </li></ul></div> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h1"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_2_0_1_10_23_2007"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_2_0_1_10_23_2007">Version 2.0.1 10/23/2007</a> </h3> <p> Bugs Fixed: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> <code class="computeroutput"><span class="identifier">sub_match</span><span class="special"><></span></code> constructor copies singular iterator causing debug assert. </li></ul></div> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h2"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_2_0_0__10_12_2007"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_2_0_0__10_12_2007">Version 2.0.0, 10/12/2007</a> </h3> <p> New Features: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> <li class="listitem"> Semantic actions </li> <li class="listitem"> Custom assertions </li> <li class="listitem"> Named captures </li> <li class="listitem"> Dynamic regex grammars </li> <li class="listitem"> Recursive dynamic regexes with <code class="literal">(?R)</code> construct </li> <li class="listitem"> Support for searching non-character data </li> <li class="listitem"> Better errors for invalid static regexes </li> <li class="listitem"> Range-based regex algorithm interface </li> <li class="listitem"> <code class="computeroutput"><span class="identifier">match_flag_type</span><span class="special">::</span><span class="identifier">format_perl</span></code>, <code class="computeroutput"><span class="identifier">match_flag_type</span><span class="special">::</span><span class="identifier">format_sed</span></code>, and <code class="computeroutput"><span class="identifier">match_flag_type</span><span class="special">::</span><span class="identifier">format_all</span></code> </li> <li class="listitem"> <code class="computeroutput"><span class="keyword">operator</span><span class="special">+(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">,</span> <span class="identifier">sub_match</span><span class="special"><>)</span></code> and variants </li> <li class="listitem"> Version 2 regex traits get <code class="computeroutput"><span class="identifier">tolower</span><span class="special">()</span></code> and <code class="computeroutput"><span class="identifier">toupper</span><span class="special">()</span></code> </li> </ul></div> <p> Bugs Fixed: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> Complementing single-character sets like <code class="computeroutput"><span class="special">~(</span><span class="identifier">set</span><span class="special">=</span><span class="char">'a'</span><span class="special">)</span></code> works. </li></ul></div> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h3"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_1_0_2__april_27__2007"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_1_0_2__april_27__2007">Version 1.0.2, April 27, 2007</a> </h3> <p> Bugs Fixed: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> Back-references greater than nine work as advertized. </li></ul></div> <p> This is the version that shipped as part of Boost 1.34. </p> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h4"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_1_0_1__october_2__2006"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_1_0_1__october_2__2006">Version 1.0.1, October 2, 2006</a> </h3> <p> Bugs Fixed: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> <code class="computeroutput"><span class="identifier">match_results</span><span class="special">::</span><span class="identifier">position</span><span class="special">()</span></code> works for nested results. </li></ul></div> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h5"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_1_0_0__march_16__2006"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_1_0_0__march_16__2006">Version 1.0.0, March 16, 2006</a> </h3> <p> Version 1.0! </p> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h6"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_0_9_6__august_19__2005"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_0_9_6__august_19__2005">Version 0.9.6, August 19, 2005</a> </h3> <p> The version reviewed for acceptance into Boost. The review began September 8, 2005. Xpressive was accepted into Boost on September 28, 2005. </p> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h7"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_0_9_3__june_30__2005"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_0_9_3__june_30__2005">Version 0.9.3, June 30, 2005</a> </h3> <p> New Features: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> <li class="listitem"> TR1-style regex_traits interface </li> <li class="listitem"> Speed enhancements </li> <li class="listitem"> <code class="computeroutput"><span class="identifier">syntax_option_type</span><span class="special">::</span><span class="identifier">ignore_white_space</span></code> </li> </ul></div> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h8"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_0_9_0__september_2__2004"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_0_9_0__september_2__2004">Version 0.9.0, September 2, 2004</a> </h3> <p> New Features: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> It sort of works. </li></ul></div> <h3> <a name="boost_xpressive.appendices.appendix_1__history.h9"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_1__history.version_0_0_1__november_16__2003"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_1__history.version_0_0_1__november_16__2003">Version 0.0.1, November 16, 2003</a> </h3> <p> Announcement of xpressive: <a href="http://lists.boost.org/Archives/boost/2003/11/56312.php" target="_top">http://lists.boost.org/Archives/boost/2003/11/56312.php</a> </p> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_xpressive.appendices.appendix_2__not_yet_implemented"></a><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_2__not_yet_implemented" title="Appendix 2: Not Yet Implemented">Appendix 2: Not Yet Implemented</a> </h3></div></div></div> <p> The following features are planned for xpressive 2.X: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> <li class="listitem"> <code class="computeroutput"><span class="identifier">syntax_option_type</span><span class="special">::</span><span class="identifier">collate</span></code> </li> <li class="listitem"> Collation sequences such as <code class="literal">[.a.]</code> </li> <li class="listitem"> Equivalence classes like <code class="literal">[=a=]</code> </li> <li class="listitem"> Control of nested results generation with <code class="computeroutput"><span class="identifier">syntax_option_type</span><span class="special">::</span><span class="identifier">nosubs</span></code>, and a <code class="computeroutput"><span class="identifier">nosubs</span><span class="special">()</span></code> modifier for static xpressive. </li> </ul></div> <p> Here are some wish-list features. You or your company should consider hiring me to implement them! </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> <li class="listitem"> Optimized DFA back-end for simple, fast regexing. </li> <li class="listitem"> Different regex compiler front ends for basic, extended, awk, grep and egrep regex syntax. </li> <li class="listitem"> Fine-grained control over the dynamic regex syntax </li> <li class="listitem"> Optional integration with ICU for full Unicode support. </li> <li class="listitem"> Improved localization support, possibly as a custom facet for <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">locale</span></code>. </li> </ul></div> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_xpressive.appendices.appendix_3__differences_from_boost_regex"></a><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_3__differences_from_boost_regex" title="Appendix 3: Differences from Boost.Regex">Appendix 3: Differences from Boost.Regex</a> </h3></div></div></div> <p> Since many of xpressive's users are likely to be familiar with the <a href="../../../libs/regex" target="_top">Boost.Regex</a> library, I would be remiss if I failed to point out some important differences between xpressive and <a href="../../../libs/regex" target="_top">Boost.Regex</a>. In particular:<br> </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> <li class="listitem"> <code class="computeroutput"><span class="identifier">xpressive</span><span class="special">::</span><span class="identifier">basic_regex</span><span class="special"><></span></code> is a template on the iterator type, not the character type. </li> <li class="listitem"> <code class="computeroutput"><span class="identifier">xpressive</span><span class="special">::</span><span class="identifier">basic_regex</span><span class="special"><></span></code> cannot be constructed directly from a string; rather, you must use <code class="computeroutput"><span class="identifier">basic_regex</span><span class="special">::</span><span class="identifier">compile</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">regex_compiler</span><span class="special"><></span></code> to build a regex object from a string. </li> <li class="listitem"> <code class="computeroutput"><span class="identifier">xpressive</span><span class="special">::</span><span class="identifier">basic_regex</span><span class="special"><></span></code> does not have an <code class="computeroutput"><span class="identifier">imbue</span><span class="special">()</span></code> member function; rather, the <code class="computeroutput"><span class="identifier">imbue</span><span class="special">()</span></code> member function is in the <code class="computeroutput"><span class="identifier">xpressive</span><span class="special">::</span><span class="identifier">regex_compiler</span><span class="special"><></span></code> factory. </li> <li class="listitem"> <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">basic_regex</span><span class="special"><></span></code> has a subset of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><></span></code>'s members. <code class="computeroutput"><span class="identifier">xpressive</span><span class="special">::</span><span class="identifier">basic_regex</span><span class="special"><></span></code> does not. The members lacking are: <code class="computeroutput"><span class="identifier">assign</span><span class="special">()</span></code>, <code class="computeroutput"><span class="keyword">operator</span><span class="special">[]()</span></code>, <code class="computeroutput"><span class="identifier">max_size</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">begin</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">end</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">size</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">compare</span><span class="special">()</span></code>, and <code class="computeroutput"><span class="keyword">operator</span><span class="special">=(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><>)</span></code>. </li> <li class="listitem"> Other member functions that exist in <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">basic_regex</span><span class="special"><></span></code> but do not exist in <code class="computeroutput"><span class="identifier">xpressive</span><span class="special">::</span><span class="identifier">basic_regex</span><span class="special"><></span></code> are: <code class="computeroutput"><span class="identifier">set_expression</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">get_allocator</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">imbue</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">getloc</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">getflags</span><span class="special">()</span></code>, and <code class="computeroutput"><span class="identifier">str</span><span class="special">()</span></code>. </li> <li class="listitem"> <code class="computeroutput"><span class="identifier">xpressive</span><span class="special">::</span><span class="identifier">basic_regex</span><span class="special"><></span></code> does not have a RegexTraits template parameter. Customization of regex syntax and localization behavior will be controlled by <code class="computeroutput"><span class="identifier">regex_compiler</span><span class="special"><></span></code> and a custom regex facet for <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">locale</span></code>. </li> <li class="listitem"> <code class="computeroutput"><span class="identifier">xpressive</span><span class="special">::</span><span class="identifier">basic_regex</span><span class="special"><></span></code> and <code class="computeroutput"><span class="identifier">xpressive</span><span class="special">::</span><span class="identifier">match_results</span><span class="special"><></span></code> do not have an Allocator template parameter. This is by design. </li> <li class="listitem"> <code class="computeroutput"><span class="identifier">match_not_dot_null</span></code> and <code class="computeroutput"><span class="identifier">match_not_dot_newline</span></code> have moved from the <code class="computeroutput"><span class="identifier">match_flag_type</span></code> enum to the <code class="computeroutput"><span class="identifier">syntax_option_type</span></code> enum, and they have changed names to <code class="computeroutput"><span class="identifier">not_dot_null</span></code> and <code class="computeroutput"><span class="identifier">not_dot_newline</span></code>. </li> <li class="listitem"> The following <code class="computeroutput"><span class="identifier">syntax_option_type</span></code> enumeration values are not supported: <code class="computeroutput"><span class="identifier">escape_in_lists</span></code>, <code class="computeroutput"><span class="identifier">char_classes</span></code>, <code class="computeroutput"><span class="identifier">intervals</span></code>, <code class="computeroutput"><span class="identifier">limited_ops</span></code>, <code class="computeroutput"><span class="identifier">newline_alt</span></code>, <code class="computeroutput"><span class="identifier">bk_plus_qm</span></code>, <code class="computeroutput"><span class="identifier">bk_braces</span></code>, <code class="computeroutput"><span class="identifier">bk_parens</span></code>, <code class="computeroutput"><span class="identifier">bk_refs</span></code>, <code class="computeroutput"><span class="identifier">bk_vbar</span></code>, <code class="computeroutput"><span class="identifier">use_except</span></code>, <code class="computeroutput"><span class="identifier">failbit</span></code>, <code class="computeroutput"><span class="identifier">literal</span></code>, <code class="computeroutput"><span class="identifier">perlex</span></code>, <code class="computeroutput"><span class="identifier">basic</span></code>, <code class="computeroutput"><span class="identifier">extended</span></code>, <code class="computeroutput"><span class="identifier">emacs</span></code>, <code class="computeroutput"><span class="identifier">awk</span></code>, <code class="computeroutput"><span class="identifier">grep</span></code> ,<code class="computeroutput"><span class="identifier">egrep</span></code>, <code class="computeroutput"><span class="identifier">sed</span></code>, <code class="computeroutput"><span class="identifier">JavaScript</span></code>, <code class="computeroutput"><span class="identifier">JScript</span></code>. </li> <li class="listitem"> The following <code class="computeroutput"><span class="identifier">match_flag_type</span></code> enumeration values are not supported: <code class="computeroutput"><span class="identifier">match_not_bob</span></code>, <code class="computeroutput"><span class="identifier">match_not_eob</span></code>, <code class="computeroutput"><span class="identifier">match_perl</span></code>, <code class="computeroutput"><span class="identifier">match_posix</span></code>, and <code class="computeroutput"><span class="identifier">match_extra</span></code>. </li> </ul></div> <p> Also, in the current implementation, the regex algorithms in xpressive will not detect pathological behavior and abort by throwing an exception. It is up to you to write efficient patterns that do not behave pathologically. </p> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_xpressive.appendices.perf"></a><a class="link" href="appendices.html#boost_xpressive.appendices.perf" title="Appendix 4: Performance Comparison">Appendix 4: Performance Comparison</a> </h3></div></div></div> <div class="toc"><dl class="toc"> <dt><span class="section"><a href="appendices.html#boost_xpressive.appendices.perf.perf_gcc">xpressive vs. Boost.Regex with GCC (Cygwin)</a></span></dt> <dt><span class="section"><a href="appendices.html#boost_xpressive.appendices.perf.perf_msvc">xpressive vs. Boost.Regex with Visual C++</a></span></dt> </dl></div> <p> The performance of xpressive is competitive with <a href="../../../libs/regex" target="_top">Boost.Regex</a>. I have run performance benchmarks comparing static xpressive, dynamic xpressive and <a href="../../../libs/regex" target="_top">Boost.Regex</a> on two platforms: gcc (Cygwin) and Visual C++. The tests include short matches and long searches. For both platforms, xpressive comes off well on short matches and roughly on par with <a href="../../../libs/regex" target="_top">Boost.Regex</a> on long searches. </p> <p> <disclaimer> As with all benchmarks, the true test is how xpressive performs with <span class="emphasis"><em>your</em></span> patterns, <span class="emphasis"><em>your</em></span> input, and <span class="emphasis"><em>your</em></span> platform, so if performance matters in your application, it's best to run your own tests. </disclaimer> </p> <div class="section"> <div class="titlepage"><div><div><h4 class="title"> <a name="boost_xpressive.appendices.perf.perf_gcc"></a><a class="link" href="appendices.html#boost_xpressive.appendices.perf.perf_gcc" title="xpressive vs. Boost.Regex with GCC (Cygwin)">xpressive vs. Boost.Regex with GCC (Cygwin)</a> </h4></div></div></div> <p> Below are the results of a performance comparison between: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> <li class="listitem"> static xpressive </li> <li class="listitem"> dynamic xpressive </li> <li class="listitem"> <a href="../../../libs/regex" target="_top">Boost.Regex</a> </li> </ul></div> <div class="variablelist"> <p class="title"><b>Test Specifications</b></p> <dl class="variablelist"> <dt><span class="term">Hardware:</span></dt> <dd><p> hyper-threaded 3GHz Xeon with 1Gb RAM </p></dd> <dt><span class="term">Operating System:</span></dt> <dd><p> Windows XP Pro + Cygwin </p></dd> <dt><span class="term">Compiler:</span></dt> <dd><p> GNU C++ version 3.4.4 (Cygwin special) </p></dd> <dt><span class="term">C++ Standard Library:</span></dt> <dd><p> GNU libstdc++ version 3.4.4 </p></dd> <dt><span class="term"><a href="../../../libs/regex" target="_top">Boost.Regex</a> Version:</span></dt> <dd><p> 1.33+, BOOST_REGEX_USE_CPP_LOCALE, BOOST_REGEX_RECURSIVE </p></dd> <dt><span class="term">xpressive Version:</span></dt> <dd><p> 0.9.6a </p></dd> </dl> </div> <h3> <a name="boost_xpressive.appendices.perf.perf_gcc.h0"></a> <span class="phrase"><a name="boost_xpressive.appendices.perf.perf_gcc.comparison_1__short_matches"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.perf.perf_gcc.comparison_1__short_matches">Comparison 1: Short Matches</a> </h3> <p> The following tests evaluate the time taken to match the expression to the input string. For each result, the top number has been normalized relative to the fastest time, so 1.0 is as good as it gets. The bottom number (in parentheses) is the actual time in seconds. The best time has been marked in green. </p> <div class="informaltable"> <h5> <a name="idp541842480"></a><span class="table-title">Short Matches</span> </h5> <table class="table"> <colgroup> <col> <col> <col> <col> <col> </colgroup> <thead><tr> <th>static xpressive</th> <th>dynamic xpressive</th> <th>Boost</th> <th>Text</th> <th>Expression</th> </tr></thead> <tbody> <tr> <td><span class="highlight">1<p></p>(8.79e‑07s)</span></td> <td><span class="highlight">1.08<p></p>(9.54e‑07s)</span></td> <td>2.51<p></p>(2.2e‑06s)</td> <td>100- this is a line of ftp response which contains a message string</td> <td><code class="literal">^([0-9]+)(\-| |$)(.*)$</code></td> </tr> <tr> <td><span class="highlight">1.06<p></p>(1.07e‑06s)</span></td> <td><span class="highlight">1<p></p>(1.01e‑06s)</span></td> <td>4.01<p></p>(4.06e‑06s)</td> <td>1234-5678-1234-456</td> <td><code class="literal">([[:digit:]]{4}[- ]){3}[[:digit:]]{3,4}</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(1.4e‑06s)</span></td> <td>1.13<p></p>(1.58e‑06s)</td> <td>2.89<p></p>(4.05e‑06s)</td> <td>john_maddock@compuserve.com</td> <td><code class="literal">^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(1.28e‑06s)</span></td> <td>1.16<p></p>(1.49e‑06s)</td> <td>3.07<p></p>(3.94e‑06s)</td> <td>foo12@foo.edu</td> <td><code class="literal">^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(1.22e‑06s)</span></td> <td>1.2<p></p>(1.46e‑06s)</td> <td>3.22<p></p>(3.93e‑06s)</td> <td>bob.smith@foo.tv</td> <td><code class="literal">^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$</code></td> </tr> <tr> <td><span class="highlight">1.04<p></p>(8.64e‑07s)</span></td> <td><span class="highlight">1<p></p>(8.34e‑07s)</span></td> <td>2.5<p></p>(2.09e‑06s)</td> <td>EH10 2QQ</td> <td><code class="literal">^[a-zA-Z]{1,2}[0-9][0-9A-Za-z]{0,1} {0,1}[0-9][A-Za-z]{2}$</code></td> </tr> <tr> <td>1.11<p></p>(9.09e‑07s)</td> <td><span class="highlight">1<p></p>(8.19e‑07s)</span></td> <td>2.47<p></p>(2.03e‑06s)</td> <td>G1 1AA</td> <td><code class="literal">^[a-zA-Z]{1,2}[0-9][0-9A-Za-z]{0,1} {0,1}[0-9][A-Za-z]{2}$</code></td> </tr> <tr> <td>1.12<p></p>(9.38e‑07s)</td> <td><span class="highlight">1<p></p>(8.34e‑07s)</span></td> <td>2.5<p></p>(2.08e‑06s)</td> <td>SW1 1ZZ</td> <td><code class="literal">^[a-zA-Z]{1,2}[0-9][0-9A-Za-z]{0,1} {0,1}[0-9][A-Za-z]{2}$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(7.9e‑07s)</span></td> <td><span class="highlight">1.06<p></p>(8.34e‑07s)</span></td> <td>2.49<p></p>(1.96e‑06s)</td> <td>4/1/2001</td> <td><code class="literal">^[[:digit:]]{1,2}/[[:digit:]]{1,2}/[[:digit:]]{4}$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(8.19e‑07s)</span></td> <td><span class="highlight">1.04<p></p>(8.49e‑07s)</span></td> <td>2.4<p></p>(1.97e‑06s)</td> <td>12/12/2001</td> <td><code class="literal">^[[:digit:]]{1,2}/[[:digit:]]{1,2}/[[:digit:]]{4}$</code></td> </tr> <tr> <td><span class="highlight">1.09<p></p>(8.95e‑07s)</span></td> <td><span class="highlight">1<p></p>(8.19e‑07s)</span></td> <td>2.4<p></p>(1.96e‑06s)</td> <td>123</td> <td><code class="literal">^[-+]?[[:digit:]]*\.?[[:digit:]]*$</code></td> </tr> <tr> <td>1.11<p></p>(8.79e‑07s)</td> <td><span class="highlight">1<p></p>(7.9e‑07s)</span></td> <td>2.57<p></p>(2.03e‑06s)</td> <td>+3.14159</td> <td><code class="literal">^[-+]?[[:digit:]]*\.?[[:digit:]]*$</code></td> </tr> <tr> <td><span class="highlight">1.09<p></p>(8.94e‑07s)</span></td> <td><span class="highlight">1<p></p>(8.19e‑07s)</span></td> <td>2.47<p></p>(2.03e‑06s)</td> <td>-3.14159</td> <td><code class="literal">^[-+]?[[:digit:]]*\.?[[:digit:]]*$</code></td> </tr> </tbody> </table> </div> <h3> <a name="boost_xpressive.appendices.perf.perf_gcc.h1"></a> <span class="phrase"><a name="boost_xpressive.appendices.perf.perf_gcc.comparison_2__long_searches"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.perf.perf_gcc.comparison_2__long_searches">Comparison 2: Long Searches</a> </h3> <p> The next test measures the time to find <span class="emphasis"><em>all</em></span> matches in a long English text. The text is the <a href="http://www.gutenberg.org/dirs/3/2/0/3200/3200.zip" target="_top">complete works of Mark Twain</a>, from <a href="http://promo.net/pg/" target="_top">Project Gutenberg</a>. The text is 19Mb long. As above, the top number is the normalized time and the bottom number is the actual time. The best time is in green. </p> <div class="informaltable"> <h5> <a name="idp541903808"></a><span class="table-title">Long Searches</span> </h5> <table class="table"> <colgroup> <col> <col> <col> <col> </colgroup> <thead><tr> <th>static xpressive</th> <th>dynamic xpressive</th> <th>Boost</th> <th>Expression</th> </tr></thead> <tbody> <tr> <td><span class="highlight">1<p></p>(0.0263s)</span></td> <td><span class="highlight">1<p></p>(0.0263s)</span></td> <td>1.78<p></p>(0.0469s)</td> <td><code class="literal">Twain</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(0.0234s)</span></td> <td><span class="highlight">1<p></p>(0.0234s)</span></td> <td>1.79<p></p>(0.042s)</td> <td><code class="literal">Huck[[:alpha:]]+</code></td> </tr> <tr> <td>1.84<p></p>(1.26s)</td> <td>2.21<p></p>(1.51s)</td> <td><span class="highlight">1<p></p>(0.687s)</span></td> <td><code class="literal">[[:alpha:]]+ing</code></td> </tr> <tr> <td><span class="highlight">1.09<p></p>(0.192s)</span></td> <td>2<p></p>(0.351s)</td> <td><span class="highlight">1<p></p>(0.176s)</span></td> <td><code class="literal">^[^ ]*?Twain</code></td> </tr> <tr> <td>1.41<p></p>(0.08s)</td> <td>1.21<p></p>(0.0684s)</td> <td><span class="highlight">1<p></p>(0.0566s)</span></td> <td><code class="literal">Tom|Sawyer|Huckleberry|Finn</code></td> </tr> <tr> <td>1.56<p></p>(0.195s)</td> <td>1.12<p></p>(0.141s)</td> <td><span class="highlight">1<p></p>(0.125s)</span></td> <td><code class="literal">(Tom|Sawyer|Huckleberry|Finn).{0,30}river|river.{0,30}(Tom|Sawyer|Huckleberry|Finn)</code></td> </tr> </tbody> </table> </div> </div> <div class="section"> <div class="titlepage"><div><div><h4 class="title"> <a name="boost_xpressive.appendices.perf.perf_msvc"></a><a class="link" href="appendices.html#boost_xpressive.appendices.perf.perf_msvc" title="xpressive vs. Boost.Regex with Visual C++">xpressive vs. Boost.Regex with Visual C++</a> </h4></div></div></div> <p> Below are the results of a performance comparison between: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> <li class="listitem"> static xpressive </li> <li class="listitem"> dynamic xpressive </li> <li class="listitem"> <a href="../../../libs/regex" target="_top">Boost.Regex</a> </li> </ul></div> <div class="variablelist"> <p class="title"><b>Test Specifications</b></p> <dl class="variablelist"> <dt><span class="term">Hardware:</span></dt> <dd><p> hyper-threaded 3GHz Xeon with 1Gb RAM </p></dd> <dt><span class="term">Operating System:</span></dt> <dd><p> Windows XP Pro </p></dd> <dt><span class="term">Compiler:</span></dt> <dd><p> Visual C++ .NET 2003 (7.1) </p></dd> <dt><span class="term">C++ Standard Library:</span></dt> <dd><p> Dinkumware, version 313 </p></dd> <dt><span class="term"><a href="../../../libs/regex" target="_top">Boost.Regex</a> Version:</span></dt> <dd><p> 1.33+, BOOST_REGEX_USE_CPP_LOCALE, BOOST_REGEX_RECURSIVE </p></dd> <dt><span class="term">xpressive Version:</span></dt> <dd><p> 0.9.6a </p></dd> </dl> </div> <h3> <a name="boost_xpressive.appendices.perf.perf_msvc.h0"></a> <span class="phrase"><a name="boost_xpressive.appendices.perf.perf_msvc.comparison_1__short_matches"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.perf.perf_msvc.comparison_1__short_matches">Comparison 1: Short Matches</a> </h3> <p> The following tests evaluate the time taken to match the expression to the input string. For each result, the top number has been normalized relative to the fastest time, so 1.0 is as good as it gets. The bottom number (in parentheses) is the actual time in seconds. The best time has been marked in green. </p> <div class="informaltable"> <h5> <a name="idp541950784"></a><span class="table-title">Short Matches</span> </h5> <table class="table"> <colgroup> <col> <col> <col> <col> <col> </colgroup> <thead><tr> <th>static xpressive</th> <th>dynamic xpressive</th> <th>Boost</th> <th>Text</th> <th>Expression</th> </tr></thead> <tbody> <tr> <td><span class="highlight">1<p></p>(3.2e‑007s)</span></td> <td>1.37<p></p>(4.4e‑007s)</td> <td>2.38<p></p>(7.6e‑007s)</td> <td>100- this is a line of ftp response which contains a message string</td> <td><code class="literal">^([0-9]+)(\-| |$)(.*)$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(6.4e‑007s)</span></td> <td>1.12<p></p>(7.15e‑007s)</td> <td>1.72<p></p>(1.1e‑006s)</td> <td>1234-5678-1234-456</td> <td><code class="literal">([[:digit:]]{4}[- ]){3}[[:digit:]]{3,4}</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(9.82e‑007s)</span></td> <td>1.3<p></p>(1.28e‑006s)</td> <td>1.61<p></p>(1.58e‑006s)</td> <td>john_maddock@compuserve.com</td> <td><code class="literal">^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(8.94e‑007s)</span></td> <td>1.3<p></p>(1.16e‑006s)</td> <td>1.7<p></p>(1.52e‑006s)</td> <td>foo12@foo.edu</td> <td><code class="literal">^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(9.09e‑007s)</span></td> <td>1.28<p></p>(1.16e‑006s)</td> <td>1.67<p></p>(1.52e‑006s)</td> <td>bob.smith@foo.tv</td> <td><code class="literal">^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(3.06e‑007s)</span></td> <td><span class="highlight">1.07<p></p>(3.28e‑007s)</span></td> <td>1.95<p></p>(5.96e‑007s)</td> <td>EH10 2QQ</td> <td><code class="literal">^[a-zA-Z]{1,2}[0-9][0-9A-Za-z]{0,1} {0,1}[0-9][A-Za-z]{2}$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(3.13e‑007s)</span></td> <td><span class="highlight">1.09<p></p>(3.42e‑007s)</span></td> <td>1.86<p></p>(5.81e‑007s)</td> <td>G1 1AA</td> <td><code class="literal">^[a-zA-Z]{1,2}[0-9][0-9A-Za-z]{0,1} {0,1}[0-9][A-Za-z]{2}$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(3.2e‑007s)</span></td> <td><span class="highlight">1.09<p></p>(3.5e‑007s)</span></td> <td>1.86<p></p>(5.96e‑007s)</td> <td>SW1 1ZZ</td> <td><code class="literal">^[a-zA-Z]{1,2}[0-9][0-9A-Za-z]{0,1} {0,1}[0-9][A-Za-z]{2}$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(2.68e‑007s)</span></td> <td>1.22<p></p>(3.28e‑007s)</td> <td>2<p></p>(5.36e‑007s)</td> <td>4/1/2001</td> <td><code class="literal">^[[:digit:]]{1,2}/[[:digit:]]{1,2}/[[:digit:]]{4}$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(2.76e‑007s)</span></td> <td>1.16<p></p>(3.2e‑007s)</td> <td>1.94<p></p>(5.36e‑007s)</td> <td>12/12/2001</td> <td><code class="literal">^[[:digit:]]{1,2}/[[:digit:]]{1,2}/[[:digit:]]{4}$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(2.98e‑007s)</span></td> <td><span class="highlight">1.03<p></p>(3.06e‑007s)</span></td> <td>1.85<p></p>(5.51e‑007s)</td> <td>123</td> <td><code class="literal">^[-+]?[[:digit:]]*\.?[[:digit:]]*$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(3.2e‑007s)</span></td> <td>1.12<p></p>(3.58e‑007s)</td> <td>1.81<p></p>(5.81e‑007s)</td> <td>+3.14159</td> <td><code class="literal">^[-+]?[[:digit:]]*\.?[[:digit:]]*$</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(3.28e‑007s)</span></td> <td>1.11<p></p>(3.65e‑007s)</td> <td>1.77<p></p>(5.81e‑007s)</td> <td>-3.14159</td> <td><code class="literal">^[-+]?[[:digit:]]*\.?[[:digit:]]*$</code></td> </tr> </tbody> </table> </div> <h3> <a name="boost_xpressive.appendices.perf.perf_msvc.h1"></a> <span class="phrase"><a name="boost_xpressive.appendices.perf.perf_msvc.comparison_2__long_searches"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.perf.perf_msvc.comparison_2__long_searches">Comparison 2: Long Searches</a> </h3> <p> The next test measures the time to find <span class="emphasis"><em>all</em></span> matches in a long English text. The text is the <a href="http://www.gutenberg.org/dirs/3/2/0/3200/3200.zip" target="_top">complete works of Mark Twain</a>, from <a href="http://promo.net/pg/" target="_top">Project Gutenberg</a>. The text is 19Mb long. As above, the top number is the normalized time and the bottom number is the actual time. The best time is in green. </p> <div class="informaltable"> <h5> <a name="idp542010944"></a><span class="table-title">Long Searches</span> </h5> <table class="table"> <colgroup> <col> <col> <col> <col> </colgroup> <thead><tr> <th>static xpressive</th> <th>dynamic xpressive</th> <th>Boost</th> <th>Expression</th> </tr></thead> <tbody> <tr> <td><span class="highlight">1<p></p>(0.019s)</span></td> <td><span class="highlight">1<p></p>(0.019s)</span></td> <td>2.98<p></p>(0.0566s)</td> <td><code class="literal">Twain</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(0.0176s)</span></td> <td><span class="highlight">1<p></p>(0.0176s)</span></td> <td>3.17<p></p>(0.0556s)</td> <td><code class="literal">Huck[[:alpha:]]+</code></td> </tr> <tr> <td>3.62<p></p>(1.78s)</td> <td>3.97<p></p>(1.95s)</td> <td><span class="highlight">1<p></p>(0.492s)</span></td> <td><code class="literal">[[:alpha:]]+ing</code></td> </tr> <tr> <td>2.32<p></p>(0.344s)</td> <td>3.06<p></p>(0.453s)</td> <td><span class="highlight">1<p></p>(0.148s)</span></td> <td><code class="literal">^[^ ]*?Twain</code></td> </tr> <tr> <td><span class="highlight">1<p></p>(0.0576s)</span></td> <td><span class="highlight">1.05<p></p>(0.0606s)</span></td> <td>1.15<p></p>(0.0664s)</td> <td><code class="literal">Tom|Sawyer|Huckleberry|Finn</code></td> </tr> <tr> <td>1.24<p></p>(0.164s)</td> <td>1.44<p></p>(0.191s)</td> <td><span class="highlight">1<p></p>(0.133s)</span></td> <td><code class="literal">(Tom|Sawyer|Huckleberry|Finn).{0,30}river|river.{0,30}(Tom|Sawyer|Huckleberry|Finn)</code></td> </tr> </tbody> </table> </div> </div> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="xpressive.appendices.appendix_5__implementation_notes"></a><a class="link" href="appendices.html#xpressive.appendices.appendix_5__implementation_notes" title="Appendix 5: Implementation Notes">Appendix 5: Implementation Notes</a> </h3></div></div></div> <div class="toc"><dl class="toc"><dt><span class="section"><a href="appendices.html#boost_xpressive.appendices.appendix_5__implementation_notes.cycle_collection_with___tracking_ptr___">Cycle collection with <code class="literal">tracking_ptr<></code></a></span></dt></dl></div> <div class="section"> <div class="titlepage"><div><div><h4 class="title"> <a name="boost_xpressive.appendices.appendix_5__implementation_notes.cycle_collection_with___tracking_ptr___"></a><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_5__implementation_notes.cycle_collection_with___tracking_ptr___" title="Cycle collection with tracking_ptr<>">Cycle collection with <code class="literal">tracking_ptr<></code></a> </h4></div></div></div> <p> In xpressive, regex objects can refer to each other and themselves by value or by reference. In addition, they ref-count their referenced regexes to keep them alive. This creates the possibility for cyclic reference counts, and raises the possibility of memory leaks. xpressive avoids leaks by using a type called <code class="computeroutput"><span class="identifier">tracking_ptr</span><span class="special"><></span></code>. This doc describes at a high level how <code class="computeroutput"><span class="identifier">tracking_ptr</span><span class="special"><></span></code> works. </p> <h3> <a name="boost_xpressive.appendices.appendix_5__implementation_notes.cycle_collection_with___tracking_ptr___.h0"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_5__implementation_notes.cycle_collection_with___tracking_ptr___.constraints"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_5__implementation_notes.cycle_collection_with___tracking_ptr___.constraints">Constraints</a> </h3> <p> Our solution must meet the following design constraints: </p> <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> <li class="listitem"> No dangling references: All objects referred to directly or indirectly must be kept alive as long as the references are needed. </li> <li class="listitem"> No leaks: all objects must be freed eventually. </li> <li class="listitem"> No user intervention: The solution must not require users to explicitly invoke some cycle collection routine. </li> <li class="listitem"> Clean-up is no-throw: The collection phase will likely be called from a destructor, so it must never throw an exception under any circumstance. </li> </ul></div> <h3> <a name="boost_xpressive.appendices.appendix_5__implementation_notes.cycle_collection_with___tracking_ptr___.h1"></a> <span class="phrase"><a name="boost_xpressive.appendices.appendix_5__implementation_notes.cycle_collection_with___tracking_ptr___.handle_body_idiom"></a></span><a class="link" href="appendices.html#boost_xpressive.appendices.appendix_5__implementation_notes.cycle_collection_with___tracking_ptr___.handle_body_idiom">Handle-Body Idiom</a> </h3> <p> To use <code class="computeroutput"><span class="identifier">tracking_ptr</span><span class="special"><></span></code>, you must separate your type into a handle and a body. In the case of xpressive, the handle type is called <code class="computeroutput"><span class="identifier">basic_regex</span><span class="special"><></span></code> and the body is called <code class="computeroutput"><span class="identifier">regex_impl</span><span class="special"><></span></code>. The handle will store a <code class="computeroutput"><span class="identifier">tracking_ptr</span><span class="special"><></span></code> to the body. </p> <p> The body type must inherit from <code class="computeroutput"><span class="identifier">enable_reference_tracking</span><span class="special"><></span></code>. This gives the body the bookkeeping data structures that <code class="computeroutput"><span class="identifier">tracking_ptr</span><span class="special"><></span></code> will use. In particular, it gives the body: </p> <div class="orderedlist"><ol class="orderedlist" type="1"> <li class="listitem"> <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">set</span><span class="special">&