forked from boostorg/regex
Eric Niebler
cfacfddccd
https://svn.boost.org/svn/boost/trunk ........ r44114 | emildotchevski | 2008-04-08 14:29:37 -0700 (Tue, 08 Apr 2008) | 1 line fixed compile errors, removed tabs as required. ........ r44118 | djowel | 2008-04-08 18:29:12 -0700 (Tue, 08 Apr 2008) | 7 lines In preparation for spirit2: * flat includes * home directory * forwarding headers * classic spirit ........ r44119 | djowel | 2008-04-08 18:51:47 -0700 (Tue, 08 Apr 2008) | 7 lines In preparation for spirit2: * flat includes * home directory * forwarding headers * classic spirit ........ r44120 | hkaiser | 2008-04-08 19:17:53 -0700 (Tue, 08 Apr 2008) | 1 line Fixed one more include path ........ r44121 | johnmaddock | 2008-04-09 04:34:20 -0700 (Wed, 09 Apr 2008) | 1 line Run config_info and config_test in both single and multi-thread modes. ........ r44122 | johnmaddock | 2008-04-09 04:34:45 -0700 (Wed, 09 Apr 2008) | 1 line Run config_info and config_test in both single and multi-thread modes. ........ r44123 | johnmaddock | 2008-04-09 04:35:36 -0700 (Wed, 09 Apr 2008) | 1 line Added needed #includes. ........ r44124 | johnmaddock | 2008-04-09 04:45:15 -0700 (Wed, 09 Apr 2008) | 1 line Added improved SVG support. ........ r44125 | hkaiser | 2008-04-09 06:50:03 -0700 (Wed, 09 Apr 2008) | 1 line Fixed #pragma message directives and a couple of forwarding headers. ........ r44126 | johnmaddock | 2008-04-09 08:21:03 -0700 (Wed, 09 Apr 2008) | 1 line Fix bug report #1797. ........ r44127 | johnmaddock | 2008-04-09 08:31:33 -0700 (Wed, 09 Apr 2008) | 1 line Update for bug report #1790. ........ r44128 | johnmaddock | 2008-04-09 08:32:08 -0700 (Wed, 09 Apr 2008) | 1 line Fix for bug #1790. ........ r44130 | danieljames | 2008-04-09 10:26:31 -0700 (Wed, 09 Apr 2008) | 1 line Fix a typo. ........ r44131 | danieljames | 2008-04-09 10:27:08 -0700 (Wed, 09 Apr 2008) | 1 line Rebuild the function types documentation. ........ r44132 | pdimov | 2008-04-09 10:49:20 -0700 (Wed, 09 Apr 2008) | 1 line Proper try_lock semantics. ........ r44134 | emildotchevski | 2008-04-09 11:48:39 -0700 (Wed, 09 Apr 2008) | 1 line missing include ........ r44136 | anthonyw | 2008-04-09 12:33:06 -0700 (Wed, 09 Apr 2008) | 1 line Added test for trac ticket #1803: condition_variable::notify_one may fail to wake a waiting thread on win32 ........ r44137 | pdimov | 2008-04-09 12:58:54 -0700 (Wed, 09 Apr 2008) | 1 line sp_counted_base_spin.hpp added, enabled by BOOST_SP_USE_SPINLOCK. ........ r44138 | pdimov | 2008-04-09 14:08:39 -0700 (Wed, 09 Apr 2008) | 1 line spinlock_gcc_arm.hpp added. ........ r44139 | grafik | 2008-04-09 14:20:28 -0700 (Wed, 09 Apr 2008) | 1 line Add ARM architecture/instrustion-set. ........ r44140 | pdimov | 2008-04-09 16:19:22 -0700 (Wed, 09 Apr 2008) | 1 line ARM assembly fix. ........ r44145 | johnmaddock | 2008-04-10 05:46:41 -0700 (Thu, 10 Apr 2008) | 2 lines Doh! Changes to code should actually compile! A fix for the last change. ........ r44146 | anthonyw | 2008-04-10 06:14:43 -0700 (Thu, 10 Apr 2008) | 1 line fix for notify problem in trac ticket #1803 ........ r44147 | anthonyw | 2008-04-10 06:27:44 -0700 (Thu, 10 Apr 2008) | 1 line fix for trac ticket #1804 ........ r44148 | anthonyw | 2008-04-10 06:35:07 -0700 (Thu, 10 Apr 2008) | 1 line Added native_handle to thread on posix platforms ........ r44149 | anthonyw | 2008-04-10 07:07:39 -0700 (Thu, 10 Apr 2008) | 1 line added overloads of timed_lock_shared with a relative timeout to shared_mutex ........ r44150 | anthonyw | 2008-04-10 07:15:26 -0700 (Thu, 10 Apr 2008) | 1 line added tests for plain timed_lock on shared_mutex ........ r44151 | daniel_frey | 2008-04-10 07:38:14 -0700 (Thu, 10 Apr 2008) | 1 line Added test and fix for "convertible to bool" requirement ........ r44152 | anthonyw | 2008-04-10 08:52:01 -0700 (Thu, 10 Apr 2008) | 1 line Added native_handle to condition_variable on pthreads ........ r44153 | anthonyw | 2008-04-10 11:34:42 -0700 (Thu, 10 Apr 2008) | 1 line Updated thread.hpp as catch-all header ........ r44160 | dgregor | 2008-04-10 14:05:14 -0700 (Thu, 10 Apr 2008) | 1 line Refactor mpi_datatype_cache to fix problems on VC9 ........ r44161 | danieljames | 2008-04-10 14:06:48 -0700 (Thu, 10 Apr 2008) | 2 lines Try to fix Herve's name in a couple of places. ........ r44163 | djowel | 2008-04-10 16:51:31 -0700 (Thu, 10 Apr 2008) | 1 line moving stuff to classic spirit ........ r44164 | emildotchevski | 2008-04-10 20:51:06 -0700 (Thu, 10 Apr 2008) | 1 line to_string fixes ........ r44165 | grafik | 2008-04-10 22:34:00 -0700 (Thu, 10 Apr 2008) | 1 line Use local sorted() function to support Python < 2.4. ........ r44166 | grafik | 2008-04-10 22:36:28 -0700 (Thu, 10 Apr 2008) | 1 line Add support for toolset requirements at the definition level. ........ r44167 | grafik | 2008-04-11 00:50:47 -0700 (Fri, 11 Apr 2008) | 1 line Initial support for cross-compiling to ARM architecture. ........ r44168 | anthonyw | 2008-04-11 01:52:09 -0700 (Fri, 11 Apr 2008) | 1 line Added test and fix for win32 condition_variable broadcast bug similar to #1803 ........ r44169 | johnmaddock | 2008-04-11 01:53:54 -0700 (Fri, 11 Apr 2008) | 1 line Fix doc typo from issue #1794. ........ r44170 | johnmaddock | 2008-04-11 02:21:08 -0700 (Fri, 11 Apr 2008) | 1 line Beefed up pthreads test cases. ........ r44171 | johnmaddock | 2008-04-11 02:22:31 -0700 (Fri, 11 Apr 2008) | 1 line Hopefully fix gcc/solaris single threading mode. ........ r44172 | jurko | 2008-04-11 03:51:43 -0700 (Fri, 11 Apr 2008) | 1 line Comment typo correction. ........ r44175 | dgregor | 2008-04-11 08:39:41 -0700 (Fri, 11 Apr 2008) | 1 line Fix some header-inclusion and header-ordering issues to get the MPI library compiling again. ........ r44186 | johnmaddock | 2008-04-11 10:54:47 -0700 (Fri, 11 Apr 2008) | 1 line Disable long double tests on unsupported platforms. ........ r44187 | johnmaddock | 2008-04-11 10:57:58 -0700 (Fri, 11 Apr 2008) | 1 line We don't need duplicate using declarations. ........ r44188 | johnmaddock | 2008-04-11 11:08:59 -0700 (Fri, 11 Apr 2008) | 1 line Update error levels for real_concept tests. ........ r44189 | johnmaddock | 2008-04-11 11:12:02 -0700 (Fri, 11 Apr 2008) | 1 line Update tolerance used for skewness test. ........ r44190 | hkaiser | 2008-04-11 11:19:46 -0700 (Fri, 11 Apr 2008) | 1 line Fixed reference to Spirit classic test suite ........ r44192 | emildotchevski | 2008-04-11 11:34:46 -0700 (Fri, 11 Apr 2008) | 1 line to_string adjustments ........ r44195 | jurko | 2008-04-11 14:03:06 -0700 (Fri, 11 Apr 2008) | 1 line Implemented a patch contributed by Igor Nazarenko reimplementing the list_sort() function to use a C qsort() function instead of a hand-crafted merge-sort algorithm. Makes some list sortings (e.g. 1,2,1,2,1,2,1,2,...) extremely faster, in turn significantly speeding up some project builds. ........ r44196 | hkaiser | 2008-04-11 15:01:55 -0700 (Fri, 11 Apr 2008) | 1 line Changed SpiritV1 header files to have a classic_ prefix ........ r44197 | hkaiser | 2008-04-11 15:05:25 -0700 (Fri, 11 Apr 2008) | 1 line Renamed a SpiritV1 header file I missed before ........ r44198 | hkaiser | 2008-04-11 19:35:34 -0700 (Fri, 11 Apr 2008) | 1 line Renamed PhoenixV1 files. ........ r44203 | hkaiser | 2008-04-11 20:00:17 -0700 (Fri, 11 Apr 2008) | 1 line Fixed an ambiguity. ........ r44206 | hkaiser | 2008-04-11 20:02:34 -0700 (Fri, 11 Apr 2008) | 1 line Fixed more SpiritV1 header references after renaming ........ r44246 | emildotchevski | 2008-04-11 20:27:57 -0700 (Fri, 11 Apr 2008) | 1 line removed tabs. what's wrong with tabs anyway? ........ r44342 | emildotchevski | 2008-04-11 23:08:10 -0700 (Fri, 11 Apr 2008) | 1 line documentation cleanup ........ r44343 | speedsnail | 2008-04-12 04:02:35 -0700 (Sat, 12 Apr 2008) | 2 lines Fixed a bug in for seldom used argument <property:/property-name/> in rule format-name. Added /property-name/ may be a regex. ........ r44344 | pdimov | 2008-04-12 07:27:22 -0700 (Sat, 12 Apr 2008) | 1 line shared_ptr::lock no longer requires exceptions. ........ r44346 | johnmaddock | 2008-04-12 09:01:16 -0700 (Sat, 12 Apr 2008) | 1 line Remove references to Boost.Test from the config_test target. ........ r44347 | johnmaddock | 2008-04-12 09:02:24 -0700 (Sat, 12 Apr 2008) | 1 line When -lrt is needed, it's needed in *both* single and multi-threaded builds. ........ r44350 | johnmaddock | 2008-04-12 09:27:11 -0700 (Sat, 12 Apr 2008) | 2 lines Add non central distro's to fwd.hpp. Added needed #include to bessel_ik.hpp. ........ r44351 | johnmaddock | 2008-04-12 09:28:57 -0700 (Sat, 12 Apr 2008) | 3 lines Fix declaration order in dist_nc_beta_incl_test.cpp test. Fix long long usage in sf_modf_incl_test.cpp. Adjust failure rates in test_zeta.cpp to cope with HP aCC and 128-bit long doubles. ........ r44352 | johnmaddock | 2008-04-12 09:42:28 -0700 (Sat, 12 Apr 2008) | 1 line Remove test row that causes problems for VC-7.1 due to a compiler bug. ........ r44353 | pdimov | 2008-04-12 11:22:18 -0700 (Sat, 12 Apr 2008) | 1 line sp_accept_owner added. ........ r44354 | grafik | 2008-04-12 12:44:47 -0700 (Sat, 12 Apr 2008) | 1 line Add multiple requirements for toolset subconditions instead of one composite as they are not supported for conditional requirements. Thanks to Roland for finding the problem. ........ r44355 | hkaiser | 2008-04-12 16:58:29 -0700 (Sat, 12 Apr 2008) | 1 line Changed copyright, started to apply changes for switching namespaces. ........ r44356 | djowel | 2008-04-12 17:15:11 -0700 (Sat, 12 Apr 2008) | 1 line added flat forwarding headers ........ r44357 | djowel | 2008-04-12 17:39:00 -0700 (Sat, 12 Apr 2008) | 1 line added flat forwarding headers ........ r44358 | djowel | 2008-04-12 17:54:10 -0700 (Sat, 12 Apr 2008) | 1 line adding spirit2 ........ r44359 | djowel | 2008-04-12 18:52:31 -0700 (Sat, 12 Apr 2008) | 1 line spirit2 ! :) ........ r44360 | djowel | 2008-04-12 20:02:30 -0700 (Sat, 12 Apr 2008) | 1 line spirit2 ! :) ........ r44361 | djowel | 2008-04-12 20:17:57 -0700 (Sat, 12 Apr 2008) | 1 line spirit2 ! :) ........ r44367 | andreas_huber69 | 2008-04-13 06:57:42 -0700 (Sun, 13 Apr 2008) | 1 line Changed the PingPong example to demonstrate how the inner workings of an asynchronous_state_machine<> subclass can be hidden. ........ r44369 | pdimov | 2008-04-13 08:35:40 -0700 (Sun, 13 Apr 2008) | 1 line Honor BOOST_DISABLE_THREADS; route GCC/ARM to the spinlock implementation; fall back to the spinlock implementation instead of using pthread_mutex. ........ r44370 | anthonyw | 2008-04-13 08:50:08 -0700 (Sun, 13 Apr 2008) | 1 line Added extended adopt/defer/try constructors to upgrade_lock ........ r44371 | hkaiser | 2008-04-13 09:28:27 -0700 (Sun, 13 Apr 2008) | 1 line Fixed Spirit Classic namespace switching. ........ r44372 | emildotchevski | 2008-04-13 10:07:26 -0700 (Sun, 13 Apr 2008) | 1 line minor compile error fix ........ r44374 | hkaiser | 2008-04-13 15:00:04 -0700 (Sun, 13 Apr 2008) | 1 line Added SpiritV2 test suite to regression tests. ........ r44376 | grafik | 2008-04-13 15:12:12 -0700 (Sun, 13 Apr 2008) | 1 line Move array test into canonical test subdir structure. ........ r44377 | grafik | 2008-04-13 15:24:41 -0700 (Sun, 13 Apr 2008) | 1 line Move crc test into canonical test subdir structure. ........ [SVN r44393]
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<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
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<title>Understanding Marked Sub-Expressions and Captures</title>
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<div class="section" lang="en">
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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
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<a name="boost_regex.captures"></a><a href="captures.html" title="Understanding Marked Sub-Expressions and Captures"> Understanding Marked Sub-Expressions
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and Captures</a>
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</h2></div></div></div>
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<p>
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Captures are the iterator ranges that are "captured" by marked sub-expressions
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as a regular expression gets matched. Each marked sub-expression can result
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in more than one capture, if it is matched more than once. This document explains
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how captures and marked sub-expressions in Boost.Regex are represented and
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accessed.
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</p>
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<a name="boost_regex.captures.marked_sub_expressions"></a><h5>
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<a name="id493056"></a>
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<a href="captures.html#boost_regex.captures.marked_sub_expressions">Marked sub-expressions</a>
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</h5>
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<p>
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Every time a Perl regular expression contains a parenthesis group <code class="computeroutput"><span class="special">()</span></code>, it spits out an extra field, known as a
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marked sub-expression, for example the expression:
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</p>
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<pre class="programlisting">(\w+)\W+(\w+)</pre>
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<p>
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Has two marked sub-expressions (known as $1 and $2 respectively), in addition
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the complete match is known as $&, everything before the first match as
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$`, and everything after the match as $'. So if the above expression is searched
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for within <code class="computeroutput"><span class="string">"@abc def--"</span></code>,
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then we obtain:
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<div class="informaltable"><table class="table">
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<colgroup>
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<col>
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Sub-expression
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</p>
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Text found
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</tr></thead>
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<tbody>
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<tr>
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<td>
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<p>
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$`
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</p>
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</td>
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<td>
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<p>
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"@"
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</p>
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</tr>
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<tr>
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<td>
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<p>
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$&
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</p>
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</td>
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<td>
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<p>
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"abc def"
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</td>
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</tr>
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<tr>
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<td>
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<p>
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$1
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</p>
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</td>
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<td>
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<p>
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"abc"
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</p>
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</td>
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</tr>
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<tr>
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<td>
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<p>
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$2
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</p>
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</td>
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<td>
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<p>
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"def"
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</p>
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</td>
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</tr>
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<tr>
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<td>
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<p>
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$'
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</p>
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</td>
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<td>
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<p>
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"--"
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</p>
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</td>
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</tr>
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</tbody>
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</table></div>
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<p>
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In Boost.Regex all these are accessible via the <a href="ref/match_results.html" title="match_results"><code class="computeroutput"><span class="identifier">match_results</span></code></a> class that gets filled
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in when calling one of the regular expression matching algorithms ( <a href="ref/regex_search.html" title="regex_search"><code class="computeroutput"><span class="identifier">regex_search</span></code></a>, <a href="ref/regex_match.html" title="regex_match"><code class="computeroutput"><span class="identifier">regex_match</span></code></a>, or <a href="ref/regex_iterator.html" title="regex_iterator"><code class="computeroutput"><span class="identifier">regex_iterator</span></code></a>). So given:
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</p>
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<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_results</span><span class="special"><</span><span class="identifier">IteratorType</span><span class="special">></span> <span class="identifier">m</span><span class="special">;</span>
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</pre>
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<p>
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The Perl and Boost.Regex equivalents are as follows:
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</p>
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<div class="informaltable"><table class="table">
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<colgroup>
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<col>
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<col>
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</colgroup>
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<thead><tr>
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<th>
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<p>
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Perl
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</p>
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</th>
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<th>
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<p>
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Boost.Regex
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</p>
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</th>
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</tr></thead>
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<tbody>
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<tr>
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<td>
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<p>
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$`
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</p>
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</td>
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<td>
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<p>
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<code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">prefix</span><span class="special">()</span></code>
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</p>
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</td>
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</tr>
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<tr>
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<td>
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<p>
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$&
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</p>
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</td>
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<td>
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<p>
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<code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="number">0</span><span class="special">]</span></code>
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</p>
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</td>
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</tr>
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<tr>
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<td>
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<p>
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$n
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</p>
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</td>
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<td>
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<p>
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<code class="computeroutput"><span class="identifier">m</span><span class="special">[</span><span class="identifier">n</span><span class="special">]</span></code>
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</p>
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</td>
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</tr>
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<tr>
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<td>
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<p>
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$'
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</p>
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</td>
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<td>
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<p>
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<code class="computeroutput"><span class="identifier">m</span><span class="special">.</span><span class="identifier">suffix</span><span class="special">()</span></code>
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</p>
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</td>
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</tr>
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</tbody>
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</table></div>
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<p>
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In Boost.Regex each sub-expression match is represented by a <a href="ref/sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a> object, this is basically
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just a pair of iterators denoting the start and end position of the sub-expression
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match, but there are some additional operators provided so that objects of
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type <a href="ref/sub_match.html" title="sub_match"><code class="computeroutput"><span class="identifier">sub_match</span></code></a>
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behave a lot like a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span></code>: for example they are implicitly
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convertible to a <code class="computeroutput"><span class="identifier">basic_string</span></code>,
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they can be compared to a string, added to a string, or streamed out to an
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output stream.
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</p>
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<a name="boost_regex.captures.unmatched_sub_expressions"></a><h5>
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<a name="id493679"></a>
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<a href="captures.html#boost_regex.captures.unmatched_sub_expressions">Unmatched Sub-Expressions</a>
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</h5>
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<p>
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When a regular expression match is found there is no need for all of the marked
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sub-expressions to have participated in the match, for example the expression:
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</p>
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<pre class="programlisting">(abc)|(def)</pre>
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<p>
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can match either $1 or $2, but never both at the same time. In Boost.Regex
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you can determine which sub-expressions matched by accessing the <code class="computeroutput"><span class="identifier">sub_match</span><span class="special">::</span><span class="identifier">matched</span></code> data member.
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</p>
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<a name="boost_regex.captures.repeated_captures"></a><h5>
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<a name="id493741"></a>
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<a href="captures.html#boost_regex.captures.repeated_captures">Repeated Captures</a>
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</h5>
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<p>
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When a marked sub-expression is repeated, then the sub-expression gets "captured"
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multiple times, however normally only the final capture is available, for example
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if
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</p>
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<pre class="programlisting">(?:(\w+)\W+)+</pre>
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<p>
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|
is matched against
|
|
</p>
|
|
<pre class="programlisting">one fine day</pre>
|
|
<p>
|
|
Then $1 will contain the string "day", and all the previous captures
|
|
will have been forgotten.
|
|
</p>
|
|
<p>
|
|
However, Boost.Regex has an experimental feature that allows all the capture
|
|
information to be retained - this is accessed either via the <code class="computeroutput"><span class="identifier">match_results</span><span class="special">::</span><span class="identifier">captures</span></code> member function or the <code class="computeroutput"><span class="identifier">sub_match</span><span class="special">::</span><span class="identifier">captures</span></code> member function. These functions
|
|
return a container that contains a sequence of all the captures obtained during
|
|
the regular expression matching. The following example program shows how this
|
|
information may be used:
|
|
</p>
|
|
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">regex</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
|
|
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span>
|
|
|
|
<span class="keyword">void</span> <span class="identifier">print_captures</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&</span> <span class="identifier">regx</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&</span> <span class="identifier">text</span><span class="special">)</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">e</span><span class="special">(</span><span class="identifier">regx</span><span class="special">);</span>
|
|
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">smatch</span> <span class="identifier">what</span><span class="special">;</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Expression: \""</span> <span class="special"><<</span> <span class="identifier">regx</span> <span class="special"><<</span> <span class="string">"\"\n"</span><span class="special">;</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Text: \""</span> <span class="special"><<</span> <span class="identifier">text</span> <span class="special"><<</span> <span class="string">"\"\n"</span><span class="special">;</span>
|
|
<span class="keyword">if</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex_match</span><span class="special">(</span><span class="identifier">text</span><span class="special">,</span> <span class="identifier">what</span><span class="special">,</span> <span class="identifier">e</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">match_extra</span><span class="special">))</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">unsigned</span> <span class="identifier">i</span><span class="special">,</span> <span class="identifier">j</span><span class="special">;</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"** Match found **\n Sub-Expressions:\n"</span><span class="special">;</span>
|
|
<span class="keyword">for</span><span class="special">(</span><span class="identifier">i</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="identifier">i</span> <span class="special"><</span> <span class="identifier">what</span><span class="special">.</span><span class="identifier">size</span><span class="special">();</span> <span class="special">++</span><span class="identifier">i</span><span class="special">)</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">" $"</span> <span class="special"><<</span> <span class="identifier">i</span> <span class="special"><<</span> <span class="string">" = \""</span> <span class="special"><<</span> <span class="identifier">what</span><span class="special">[</span><span class="identifier">i</span><span class="special">]</span> <span class="special"><<</span> <span class="string">"\"\n"</span><span class="special">;</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">" Captures:\n"</span><span class="special">;</span>
|
|
<span class="keyword">for</span><span class="special">(</span><span class="identifier">i</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="identifier">i</span> <span class="special"><</span> <span class="identifier">what</span><span class="special">.</span><span class="identifier">size</span><span class="special">();</span> <span class="special">++</span><span class="identifier">i</span><span class="special">)</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">" $"</span> <span class="special"><<</span> <span class="identifier">i</span> <span class="special"><<</span> <span class="string">" = {"</span><span class="special">;</span>
|
|
<span class="keyword">for</span><span class="special">(</span><span class="identifier">j</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="identifier">j</span> <span class="special"><</span> <span class="identifier">what</span><span class="special">.</span><span class="identifier">captures</span><span class="special">(</span><span class="identifier">i</span><span class="special">).</span><span class="identifier">size</span><span class="special">();</span> <span class="special">++</span><span class="identifier">j</span><span class="special">)</span>
|
|
<span class="special">{</span>
|
|
<span class="keyword">if</span><span class="special">(</span><span class="identifier">j</span><span class="special">)</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">", "</span><span class="special">;</span>
|
|
<span class="keyword">else</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">" "</span><span class="special">;</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"\""</span> <span class="special"><<</span> <span class="identifier">what</span><span class="special">.</span><span class="identifier">captures</span><span class="special">(</span><span class="identifier">i</span><span class="special">)[</span><span class="identifier">j</span><span class="special">]</span> <span class="special"><<</span> <span class="string">"\""</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">" }\n"</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
<span class="special">}</span>
|
|
<span class="keyword">else</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"** No Match found **\n"</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
<span class="special">}</span>
|
|
|
|
<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="special">,</span> <span class="keyword">char</span><span class="special">*</span> <span class="special">[])</span>
|
|
<span class="special">{</span>
|
|
<span class="identifier">print_captures</span><span class="special">(</span><span class="string">"(([[:lower:]]+)|([[:upper:]]+))+"</span><span class="special">,</span> <span class="string">"aBBcccDDDDDeeeeeeee"</span><span class="special">);</span>
|
|
<span class="identifier">print_captures</span><span class="special">(</span><span class="string">"(.*)bar|(.*)bah"</span><span class="special">,</span> <span class="string">"abcbar"</span><span class="special">);</span>
|
|
<span class="identifier">print_captures</span><span class="special">(</span><span class="string">"(.*)bar|(.*)bah"</span><span class="special">,</span> <span class="string">"abcbah"</span><span class="special">);</span>
|
|
<span class="identifier">print_captures</span><span class="special">(</span><span class="string">"^(?:(\\w+)|(?>\\W+))*$"</span><span class="special">,</span>
|
|
<span class="string">"now is the time for all good men to come to the aid of the party"</span><span class="special">);</span>
|
|
<span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
|
|
<span class="special">}</span>
|
|
</pre>
|
|
<p>
|
|
Which produces the following output:
|
|
</p>
|
|
<pre class="programlisting">Expression: "(([[:lower:]]+)|([[:upper:]]+))+"
|
|
Text: "aBBcccDDDDDeeeeeeee"
|
|
** Match found **
|
|
Sub-Expressions:
|
|
$0 = "aBBcccDDDDDeeeeeeee"
|
|
$1 = "eeeeeeee"
|
|
$2 = "eeeeeeee"
|
|
$3 = "DDDDD"
|
|
Captures:
|
|
$0 = { "aBBcccDDDDDeeeeeeee" }
|
|
$1 = { "a", "BB", "ccc", "DDDDD", "eeeeeeee" }
|
|
$2 = { "a", "ccc", "eeeeeeee" }
|
|
$3 = { "BB", "DDDDD" }
|
|
Expression: "(.*)bar|(.*)bah"
|
|
Text: "abcbar"
|
|
** Match found **
|
|
Sub-Expressions:
|
|
$0 = "abcbar"
|
|
$1 = "abc"
|
|
$2 = ""
|
|
Captures:
|
|
$0 = { "abcbar" }
|
|
$1 = { "abc" }
|
|
$2 = { }
|
|
Expression: "(.*)bar|(.*)bah"
|
|
Text: "abcbah"
|
|
** Match found **
|
|
Sub-Expressions:
|
|
$0 = "abcbah"
|
|
$1 = ""
|
|
$2 = "abc"
|
|
Captures:
|
|
$0 = { "abcbah" }
|
|
$1 = { }
|
|
$2 = { "abc" }
|
|
Expression: "^(?:(\w+)|(?>\W+))*$"
|
|
Text: "now is the time for all good men to come to the aid of the party"
|
|
** Match found **
|
|
Sub-Expressions:
|
|
$0 = "now is the time for all good men to come to the aid of the party"
|
|
$1 = "party"
|
|
Captures:
|
|
$0 = { "now is the time for all good men to come to the aid of the party" }
|
|
$1 = { "now", "is", "the", "time", "for", "all", "good", "men", "to",
|
|
"come", "to", "the", "aid", "of", "the", "party" }
|
|
</pre>
|
|
<p>
|
|
Unfortunately enabling this feature has an impact on performance (even if you
|
|
don't use it), and a much bigger impact if you do use it, therefore to use
|
|
this feature you need to:
|
|
</p>
|
|
<div class="itemizedlist"><ul type="disc">
|
|
<li>
|
|
Define BOOST_REGEX_MATCH_EXTRA for all translation units including the library
|
|
source (the best way to do this is to uncomment this define in boost/regex/user.hpp
|
|
and then rebuild everything.
|
|
</li>
|
|
<li>
|
|
Pass the match_extra flag to the particular algorithms where you actually
|
|
need the captures information (regex_search, regex_match, or regex_iterator).
|
|
</li>
|
|
</ul></div>
|
|
</div>
|
|
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
|
<td align="left"></td>
|
|
<td align="right"><div class="copyright-footer">Copyright � 1998 -2007 John Maddock<p>
|
|
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
|
</p>
|
|
</div></td>
|
|
</tr></table>
|
|
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