The regex sublanguages and engines in Ruby and Python are knockoffs of the equivalents in earlier Perls.
But this thread really ought to be focused on Perl 6.
In Perl 6 one can write:
print "match" if something ~~ /<thing>/
It looks superficially similar. But it's a scalable parsing feature, not a mere regex. That line of code will work when `something` is ten thousand lines of complex Perl 6 code and `thing` is the top rule in a grammar for parsing Perl 6 code.
I was showing Ruby code to show how its regex handling is much like Perl 5 - Perl 5 would use a sigil on 'something'. Ruby is less like Perl 6 regex-wise due to the smart match (among many other things).
> Ruby is less like Perl 6 regex-wise due to the smart match (among many other things).
In both Perl 5 and Perl 6, smart match (`~~`) with a regex on the right hand side is just an alternate spelling (Perl 5) or correct spelling (Perl 6) for `=~`. It's a tiny, trivial difference.
But a Perl 6 "regex" can be an arbitrary full blown parser or compiler. And it assumes character=grapheme. In these two regards, as in several others, Perl 6 is quite unlike Perl 5 and other langs that adopted Perl 5 regexes and/or that adopted Unicode codepoints (or worse) rather than graphemes as their fundamental "character" unit.
But this thread really ought to be focused on Perl 6.
In Perl 6 one can write:
It looks superficially similar. But it's a scalable parsing feature, not a mere regex. That line of code will work when `something` is ten thousand lines of complex Perl 6 code and `thing` is the top rule in a grammar for parsing Perl 6 code.Perl 6 is not Perl 5.