构造\ H，\V和\ N是什么意思？ [英] What do the constructs \H, \V and \N mean?

问题描述

以下结构没有很好的文档记录，但它们的确适用于PHP的特定版本;这些版本是什么，这些构造是什么以及其他实现支持这个？

The following constructs are not well documented, but they do work as of specific versions of PHP onwards; Which are these versions, what are these constructs and which other implementations support this?

• \ H


• \V


• \ N

• \H
• \V
• \N

此主题是堆栈溢出正则表达式参考。

推荐答案

\H 匹配任何非水平空格的内容。这包括制表符和所有空格分隔符Unicode字符。这与以下相同：

\H matches anything which aren't horizontal whitespace. This includes tab character and all "space separator" Unicode characters. This is the same as:

[^\h] or
[^\t\p{Zs}]

\V 是 \v 的否定类 - 它被命名为非垂直空白字符并匹配任何不是垂直空白字符的字符，在Unicode标准中被视为换行符，并且将与 \v 匹配，并且与以下内容相同如Perl 5中所介绍的那样：

\V is the negated class of \v - It is named "non vertical whitespace character" and matches any characters which aren't a vertical whitespace character of those which are treated as line breaks in the Unicode standard and would be matched by \v, and is the same as the following as introduced in Perl 5:

[^\v] or
[^\n\cK\f\r\x85\x{2028}\x{2029}]

\ N 匹配任何不是换行符的字符 \ n 。简单！

\N matches any characters which aren't the line feed character \n. Simple!

[^\n]

\ V + 和 <之间有什么区别？ code> \ N + ？_{感谢 Avinash Raj for ask。}

如文档中指定的Perl 5.10， \V 与 相同[^ \ n\cK\f\r\ x85 \ x {2028} \ x {2029}] 且不应与 \ n ， 中的任何一个匹配\ r 或 \f ，以及 Ctrl +（控制字符） （* nix）， 0x85 ， 0x2028 和 0x2029 。

What's the difference between \V+ and \N+ ?_{Thanks to Avinash Raj for asking.}

As Perl 5.10 specified in the documentation, \V is the same as [^\n\cK\f\r\x85\x{2028}\x{2029}] and shouldn't match any of \n, \r or \f, as well as Ctrl+(Control char) (*nix), 0x85, 0x2028 and 0x2029.

这些角色类很方便当您想要匹配水平文本中的所有内容时非常有效 - \V + - 或者只是消费整个段落 - \ N + - 在其他各种用例中。

These character classes are handy and incredibly effective for when you want to match everything within the horizontal text - \V+ - or simply consuming an entire paragraph - \N+ - among various other use cases.

以下实现支持 \H ， \V 和 \N ：

• Perl 5.10


• PCRE 7.2


• PHP程序员可能找出哪些版本支持这些结构的差异。当他们来自Perl 5时，必须设置PCRE版本;您可以使用 phpinfo（） 。默认情况下，PHP 5.2.2可以。


• Java 8 java.util.regex.Pattern 支持 \H 和 \V 构造已添加为实施 \h ，<$ c $的一部分c> \v ，这是不适用于Java 7 ，但尚不支持 \N 。 使用JDK8u25进行测试。

• Perl 5.10
• PCRE 7.2
• PHP programmers may find a discrepancy over which versions supports these constructs. As they came from Perl 5, one has to set the PCRE version instead; You can check this using phpinfo(). By default, PHP 5.2.2 does.
• Java 8 java.util.regex.Pattern support for \H and \V constructs has been added as part of implementing \h, \v, which was not true for Java 7, however \N is not yet supported. Tested with JDK8u25.

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