Regexp

Perl 5 to Perl 6 Regular Expression Converter [online tool]

http://www.equinoxbase.com/p5p6regconv/converter.html It is not always works, but at least give you an idea. Perl6 regex syntax is really different from normal perl and it is not [yet] well documented. Or you can prefix each regex in perl6 with :p5 to make it perl5-compatible

Syntax - re2 - I define UNIX as “30 definitions of regular expressions living under one roof.” —Don Knuth - Project Hosting on Google Code

http://code.google.com/p/re2/wiki/Syntax list of syntax supported by new regexp lib from google