Software Development - 正则表达式风味（引擎）对比

梦里梦外; 2023-06-30 02:49 17阅读 0赞

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### 正则表达式风味（引擎）说明 ###

风味是规范，引擎是实现。

<table> 
 <thead> 
  <tr> 
   <th>名称</th> 
   <th>说明</th> 
   <th>应用</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <th>.NET</th> 
   <td>由&nbsp;<a href="https://docs.microsoft.com/en-us/dotnet/api/system.text.regularexpressions" rel="nofollow"><code>System.Text.RegularExpressions</code>&nbsp;相关类</a>&nbsp;提供的正则引擎。</td> 
   <td>基于 .Net 的语言和软件。如 C#, Visual Basic.Net, F#, Powershell, Delphi for .NET 等。</td> 
  </tr> 
  <tr> 
   <th>Java</th> 
   <td>由&nbsp;<a href="https://docs.oracle.com/javase/7/docs/api/java/util/regex/package-summary.html" rel="nofollow"><code>java.util.regex</code></a>&nbsp;包提供, 在 Java 4 (JDK 1.4.x) 及更新的版本中可用。在 Java 5 (JDK 1.5.x) 和 6 (JDK 1.6.x) 中添加了一些新功能。</td> 
   <td>基于 JVM 的语言和软件，如 Java, Clojure 等。</td> 
  </tr> 
  <tr> 
   <th>Perl</th> 
   <td>内置于 Perl 的<a href="https://perldoc.perl.org/perlre.html" rel="nofollow">正则表达式引擎</a>，5.6 之前的版本不支持 Unicode。</td> 
   <td>Perl 编程语言。</td> 
  </tr> 
  <tr> 
   <th>PCRE</th> 
   <td>来自开源项目&nbsp;<a href="https://www.pcre.org/" rel="nofollow">PCRE</a>的<a href="https://www.pcre.org/original/doc/html/pcrepattern.html" rel="nofollow">正则表达式引擎</a>。 本文介绍的功能在 PCRE 5.x 和 6.x 中可用。</td> 
   <td>REALbasic(Xojo) 语言； Delphi 组件&nbsp;<code>TPerlRegEx</code>&nbsp;和 Delphi XE 和 C++Builder XE 的单元&nbsp;<code>RegularExrpessions</code>&nbsp;和&nbsp;<code>RegularExpressionsCore</code>； PHP 的&nbsp;<code>preg</code>&nbsp;函数； R 语言(<code>perl = true</code>)； COM 对象 Microsoft VBScript Regular Expressions 5.5。</td> 
  </tr> 
  <tr> 
   <th>JS(JavaScript)</th> 
   <td>由&nbsp;<a href="https://www.ecma-international.org/publications/standards/Ecma-262-arch.htm" rel="nofollow">ECMA-262 标准</a><a href="https://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262,%203rd%20edition,%20December%201999.pdf" rel="nofollow">第 3 版</a>定义的脚本语言(ECMAScript)中的正则表达式语法。</td> 
   <td>JavaScript 编程语言；VBScript 中的&nbsp;<code>RegExp</code>；ClojureScript 编程语言。</td> 
  </tr> 
  <tr> 
   <th>Python</th> 
   <td>由 Python 内置<a href="https://docs.python.org/3/library/re.html" rel="nofollow">模块&nbsp;<code>re</code></a>&nbsp;支持。</td> 
   <td>Python 编程语言。</td> 
  </tr> 
  <tr> 
   <th>Ruby</th> 
   <td>由 Ruby 内置的<a href="https://ruby-doc.org/core-2.6.4/Regexp.html" rel="nofollow">正则表达式引擎</a>。</td> 
   <td>Ruby 编程语言。</td> 
  </tr> 
  <tr> 
   <th>Tcl ARE</th> 
   <td>由 Henry Spencer 为 Tcl 8.2/8.4 中命令&nbsp;<code>regexp</code>&nbsp;开发，被称为<a href="https://wiki.tcl-lang.org/page/Regular+Expression" rel="nofollow">高级正则表达式(Advanced Regular Expressions, ARE)</a>。</td> 
   <td>Tcl 编程语言；PostgreSQL 7.4 及更新版本；wxWidgets(<code>wxRE_ADVANCED</code>)。</td> 
  </tr> 
  <tr> 
   <th>POSIX BRE</th> 
   <td>由&nbsp;<a href="https://pubs.opengroup.org/onlinepubs/9699919799/" rel="nofollow">IEEE POSIX 标准 1003</a>&nbsp;定义的<a href="https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03" rel="nofollow">基本正则表达式（Basic Regular Expressions）</a>。</td> 
   <td>Unix 上的软件工具；R 语言(<code>perl = false, extended = false</code>)；Tcl的 基本风味（Extended Regular Expressions），wxWidgets(<code>wxRE_BASIC</code>)。</td> 
  </tr> 
  <tr> 
   <th>POSIX ERE</th> 
   <td>由&nbsp;<a href="https://pubs.opengroup.org/onlinepubs/9699919799/" rel="nofollow">IEEE POSIX 标准 1003</a>&nbsp;定义的<a href="https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_04" rel="nofollow">扩展正则表达式（Extended Regular Expressions）</a>。</td> 
   <td>Unix 上的软件工具，如 awk, grep, egrep, emacs 等（Emacs 不支持 POSIX 字符类, 排序序列和等值字符）； MySQL, Oracle 数据库（ Oracle 支持标准外的后向引用，从&nbsp;<code>\1</code>&nbsp;到&nbsp;<code>\9</code>），PostgreSQL 7.3 及更早版本； PHP 的&nbsp;<code>ereg</code>&nbsp;函数，R 语言默认状态，Tcl 的扩展风味（Extended Regular Expressions），wxWidgets(<code>wxRE_EXTENDED</code>)。</td> 
  </tr> 
  <tr> 
   <th>GNU BRE</th> 
   <td><a href="https://www.gnu.org/software/sed/manual/html_node/BRE-syntax.html" rel="nofollow">GNU 基本正则表达式（GNU Basic Regular Expressions）</a>, 包含 POSIX BRE 及 GNU 扩展。</td> 
   <td>GNU 实现的经典 UNIX 工具，如 GNU/Linux 上的 sed 等。</td> 
  </tr> 
  <tr> 
   <th>GNU ERE</th> 
   <td><a href="https://www.gnu.org/software/sed/manual/html_node/ERE-syntax.html" rel="nofollow">GNU 扩展正则表达式（Extended Regular Expressions）</a>, 包含 POSIX ERE 及 GNU 扩展。</td> 
   <td>GNU 实现的经典 UNIX 工具，如 GNU/Linux 上的 egrep, grep 等。</td> 
  </tr> 
  <tr> 
   <th>XML</th> 
   <td>由&nbsp;<a href="https://www.w3.org/TR/xmlschema11-2/#regexs" rel="nofollow">XML Schema 标准的附录 G</a>定义。</td> 
   <td>XML Schema。</td> 
  </tr> 
  <tr> 
   <th>XPath</th> 
   <td>由 XQuery 1.0 和 XPath 2.0 标准中的<a href="https://www.w3.org/TR/xquery-operators/#regex-syntax" rel="nofollow">函数与运算符章节</a>定义。</td> 
   <td>XQuery, XPath。</td> 
  </tr> 
  <tr> 
   <th>JGsoft</th> 
   <td>由&nbsp;<a href="https://www.just-great-software.com/" rel="nofollow">Just Great Software</a>&nbsp;产品使用的<a href="https://www.regular-expressions.info/jgsoft.html" rel="nofollow">正则表达式引擎</a>。</td> 
   <td>PowerGREP, EditPad Pro, AceText, RegexBuddy 等。</td> 
  </tr> 
 </tbody> 
</table>

### 正则表达式风味（引擎）特性对比 ###

<table> 
 <tbody> 
  <tr> 
   <th colspan="16">字符</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>\</code>&nbsp;转义单个元字符</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\Q...\E</code>&nbsp;转义多个元字符</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>Java 6</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\x00</code>&nbsp;~&nbsp;<code>\xFF</code>&nbsp;(ASCII 字符)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\n</code>&nbsp;(换行),&nbsp;<code>\r</code>&nbsp;(回车),&nbsp;\t (制表)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\f</code>&nbsp;(换页),&nbsp;<code>\v</code>&nbsp;(竖直制表)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\a</code>&nbsp;(响铃)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\e</code>&nbsp;(转义)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\b</code>&nbsp;(退格),&nbsp;<code>\B</code>&nbsp;(反斜杠,&nbsp;<code>\</code>)</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\cA</code>&nbsp;~&nbsp;<code>\cZ</code>&nbsp;(控制字符)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\ca</code>&nbsp;~&nbsp;<code>\cz</code>&nbsp;(控制字符)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">字符类/字符集&nbsp;<code>[abc]</code></th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>[abc]</code>&nbsp;字符类</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>[^abc]</code>&nbsp;反义字符类</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>[a-z]</code>&nbsp;字符类范围</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>[\d-z]</code>&nbsp;中的&nbsp;<code>-</code>&nbsp;视为字面量</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>[a-\d]</code>&nbsp;中的&nbsp;<code>-</code>&nbsp;视为字面量</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\</code>&nbsp;转义单个字符类元字符</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\Q...\E</code>&nbsp;转义多个字符类元字符</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>Java 6</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\d</code>&nbsp;代表数字</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>ascii</td> 
   <td>option</td> 
   <td>ascii</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\w</code>&nbsp;代表单词字符</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>ascii</td> 
   <td>option</td> 
   <td>ascii</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\s</code>&nbsp;代表空白字符</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>ascii</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>ascii</td> 
  </tr> 
  <tr> 
   <td><code>\D</code>,&nbsp;<code>\W</code>&nbsp;and&nbsp;\S 代表反义字符类</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>[\b]</code>&nbsp;匹配反斜杠(<code>\</code>)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">点</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>.</code>&nbsp;匹配换行符(<code>\n</code>)外所有字符</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <th colspan="16">锚点</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>^</code>&nbsp;字符串/行开始</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>$</code>&nbsp;字符串/行结束</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\A</code>&nbsp;字符串开始</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\Z</code>&nbsp;字符串结束，最后一个\n前</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\z</code>&nbsp;字符串结束</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td><code>\Z</code></td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\`</code>&nbsp;字符串开始</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\'</code>&nbsp;字符串结束</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">单词边界</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>\b</code>&nbsp;单词的开始或结束处</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>ascii</td> 
   <td>option</td> 
   <td>ascii</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\B</code>&nbsp;不是单词的开始处或结束处</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>ascii</td> 
   <td>option</td> 
   <td>ascii</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\y</code>&nbsp;单词的开始或结束处</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\Y</code>&nbsp;不是单词的开始处或结束处</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\m</code>&nbsp;单词的开始处</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\M</code>&nbsp;单词的结束处</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\&lt;</code>&nbsp;单词的开始处</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\&gt;</code>&nbsp;单词的结束处</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">分支条件</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>|</code>&nbsp;分支条件</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>\|</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <th colspan="16">量词</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>?</code>&nbsp;0 ~ 1 次</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>\?</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>*</code>&nbsp;0 次或更多次</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>+</code>&nbsp;1 次或更多次</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>\+</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>{n}</code>&nbsp;n 次</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>\{n\}</td> 
   <td>YES</td> 
   <td>\{n\}</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>{n,m}</code>&nbsp;n ~ m 次</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>\{n,m\}</td> 
   <td>YES</td> 
   <td>\{n,m\}</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>{n,}</code>&nbsp;n 次或更多次</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>\{n,\}</td> 
   <td>YES</td> 
   <td>\{n,\}</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td>量词后加&nbsp;<code>?</code>&nbsp;转为懒惰模式</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <th colspan="16">分组与后向引用</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>(regex)</code>&nbsp;编号捕获组</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td></td> 
   <td>YES</td> 
   <td></td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>(?:regex)</code>&nbsp;非捕获组</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\1</code>&nbsp;~&nbsp;<code>\9</code>&nbsp;后向引用</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\10</code>&nbsp;~&nbsp;<code>\99</code>&nbsp;后向引用</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>n/a</td> 
   <td>no</td> 
   <td>no</td> 
   <td>n/a</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td>前向引用&nbsp;<code>\1</code>&nbsp;through&nbsp;<code>\9</code></td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>n/a</td> 
   <td>no</td> 
   <td>no</td> 
   <td>n/a</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td>嵌套引用&nbsp;<code>\1</code>&nbsp;~&nbsp;<code>\9</code></td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>n/a</td> 
   <td>no</td> 
   <td>no</td> 
   <td>n/a</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td>后向引用不存在的组报错</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>n/a</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>n/a</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td>后向引用匹配失败的组失败</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>n/a</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>n/a</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <th colspan="16">修饰器</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>(?i)</code>&nbsp;忽略大小写</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>/i only</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>flag</td> 
  </tr> 
  <tr> 
   <td><code>(?s)</code>&nbsp;点(<code>.</code>)可匹配<code>\n</code></td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>(?m)</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>flag</td> 
  </tr> 
  <tr> 
   <td><code>(?m)</code>&nbsp;行开始/结束可匹配&nbsp;<code>^</code>&nbsp;/&nbsp;$</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>/m only</td> 
   <td>YES</td> 
   <td>always on</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>flag</td> 
  </tr> 
  <tr> 
   <td><code>(?x)</code>&nbsp;忽略空白模式</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>flag</td> 
  </tr> 
  <tr> 
   <td><code>(?n)</code>&nbsp;显式匹配</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?-ismxn)</code>&nbsp;关闭模式修饰器</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?ismxn:group)</code>&nbsp;模式修饰器仅应用于本组</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">原子组与占位量词(possessive quantifiers)</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>(?&gt;regex)</code>&nbsp;原子组</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>?+</code>,&nbsp;<code>*+</code>,&nbsp;++,&nbsp;<code>{m,n}+</code>&nbsp;占位量词</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">断言</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>(?=regex)</code>&nbsp;正预测先行断言</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?!regex)</code>&nbsp;负预测先行断言</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?&lt;=text)</code>&nbsp;正回顾后发断言</td> 
   <td>full regex</td> 
   <td>full regex</td> 
   <td>finite length</td> 
   <td>fixed length</td> 
   <td>fixed + alternation</td> 
   <td>no</td> 
   <td>fixed length</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?&lt;!text)</code>&nbsp;负回顾后发断言</td> 
   <td>full regex</td> 
   <td>full regex</td> 
   <td>finite length</td> 
   <td>fixed length</td> 
   <td>fixed + alternation</td> 
   <td>no</td> 
   <td>fixed length</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">从上个匹配继续</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>\G</code>&nbsp;匹配尝试的开始</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">条件</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>(?(?=regex)then|else)</code>&nbsp;使用任意断言</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?(regex)then|else)</code></td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?(1)then|else)</code></td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?(group)then|else)</code></td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">注释</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>(?#comment)</code></td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">忽略空白</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td>支持忽略空白语法</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td>字符类作为整体</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>n/a</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td># 开启注释</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>n/a</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">Unicode 字符</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>\X</code>&nbsp;Unicode 字素</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\u0000</code>&nbsp;~&nbsp;<code>\uFFFF</code>&nbsp;(Unicode 字符)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>u"string"</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\x{0}</code>&nbsp;~&nbsp;<code>\x{FFFF}</code>&nbsp;(Unicode 字符)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">Unicode 属性, 脚本与区块</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>\pL</code>&nbsp;~&nbsp;<code>\pC</code>&nbsp;(Unicode 属性)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{L}</code>&nbsp;~&nbsp;<code>\p{C}</code>&nbsp;(Unicode 属性)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\p{Lu}</code>&nbsp;~&nbsp;<code>\p{Cn}</code>&nbsp;(Unicode 属性)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\p{L&amp;}</code>,&nbsp;<code>\p{Letter&amp;}</code>&nbsp;等同于&nbsp;<code>[\p{Lu}\p{Ll}\p{Lt}]</code>&nbsp;Unicode 属性</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{IsL}</code>&nbsp;~&nbsp;<code>\p{IsC}</code>&nbsp;(Unicode 属性)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{IsLu}</code>&nbsp;~&nbsp;<code>\p{IsCn}</code>&nbsp;(Unicode 属性)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{Letter}</code>&nbsp;~&nbsp;<code>\p{Other}</code>&nbsp;(Unicode 属性)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{Lowercase_Letter}</code>&nbsp;~&nbsp;<code>\p{Not_Assigned}</code>&nbsp;(Unicode 属性)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{IsLetter}</code>&nbsp;~&nbsp;<code>\p{IsOther}</code>&nbsp;(Unicode 属性)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{IsLowercase_Letter}</code>&nbsp;~&nbsp;<code>\p{IsNot_Assigned}</code>&nbsp;(Unicode 属性)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{Arabic}</code>&nbsp;~&nbsp;<code>\p{Yi}</code>&nbsp;(Unicode 脚本)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{IsArabic}</code>&nbsp;~&nbsp;<code>\p{IsYi}</code>&nbsp;(Unicode 脚本)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{BasicLatin}</code>&nbsp;~&nbsp;<code>\p{Specials}</code>&nbsp;(Unicode 区块)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{InBasicLatin}</code>&nbsp;~&nbsp;<code>\p{InSpecials}</code>&nbsp;(Unicode 区块)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{IsBasicLatin}</code>&nbsp;~&nbsp;<code>\p{IsSpecials}</code>&nbsp;(Unicode 区块)</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td>上方&nbsp;<code>{}</code>&nbsp;中的内容忽略大小写</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td>上方语法中长名称允许空格，边字符，下划线 (如&nbsp;<code>BasicLatin</code>&nbsp;可写为&nbsp;<code>Basic-Latin</code>&nbsp;或&nbsp;<code>Basic_Latin</code>&nbsp;或&nbsp;<code>Basic Latin</code>)</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>Java 5</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\P</code>&nbsp;上方所有&nbsp;<code>\p</code>&nbsp;的反义</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>\p{^...}</code>&nbsp;上方所有&nbsp;<code>\p{...}</code>&nbsp;的反义</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>option</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <th colspan="16">命名捕获与后向引用</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>(?&lt;name&gt;regex)</code>&nbsp;.Net 风格的命名捕获分组</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?'name'regex)</code>&nbsp;.Net 风格的命名捕获分组</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\k&lt;name&gt;</code>&nbsp;.Net 风格的命名后向引用</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\k'name'</code>&nbsp;.Net 风格的命名后向引用</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?P&lt;name&gt;regex)</code>&nbsp;Python 风格的命名捕获分组</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>(?P=name)</code>&nbsp;Python 风格的命名后向引用</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td>多个捕获组同名</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>no</td> 
   <td>n/a</td> 
   <td>no</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
   <td>n/a</td> 
  </tr> 
  <tr> 
   <th colspan="16">XML 字符类</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>\i</code>,&nbsp;<code>\I</code>,&nbsp;<code>\c</code>,&nbsp;<code>\C</code>&nbsp;XML 名称字符类</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <td><code>[abc-[abc]]</code>&nbsp;字符类差集</td> 
   <td>YES</td> 
   <td>2.0</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
  </tr> 
  <tr> 
   <th colspan="16">POSIX 方括号表达式</th> 
  </tr> 
  <tr> 
   <th>特性</th> 
   <th>JGsoft</th> 
   <th>.NET</th> 
   <th>Java</th> 
   <th>Perl</th> 
   <th>PCRE</th> 
   <th>JS</th> 
   <th>Python</th> 
   <th>Ruby</th> 
   <th>Tcl ARE</th> 
   <th>POSIX BRE</th> 
   <th>POSIX ERE</th> 
   <th>GNU BRE</th> 
   <th>GNU ERE</th> 
   <th>XML</th> 
   <th>XPath</th> 
  </tr> 
  <tr> 
   <td><code>[:alpha:]</code>&nbsp;POSIX 字符类</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>ascii</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{Alpha}</code>&nbsp;POSIX 字符类</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>ascii</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>\p{IsAlpha}</code>&nbsp;POSIX 字符类</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>[.span-ll.]</code>&nbsp;POSIX 排序序列</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
  <tr> 
   <td><code>[=x=]</code>&nbsp;POSIX 等值字符</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>no</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>YES</td> 
   <td>no</td> 
   <td>no</td> 
  </tr> 
 </tbody> 
</table>

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