Description:
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Since PHP 5.2.4, the PCRE library bundled with PHP, knows the escape sequences \h, \H, \v, \V, \k and \K.

Please add also a note, that this new features can break existing scripts.

Regards,
Carsten


Reproduce code:
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http://de.php.net/manual/en/reference.pcre.pattern.syntax.php

Expected result:
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\h, \H, \v, and \V match horizontal and vertical whitespace.

\k{name} is synonymous with \k<name> and \k'name'

\K resets the start of the current match so that everything before is not part of it.


Actual result:
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The \v escape that was in the Perl documentation for a long time was never in fact recognized.

(nothing about \h, \H, \V, \k and \K)