When we talk about a regex in the context of Perl, we don't mean Regular Expression in the sense that a computer scientist would use (ie Typ-3 language of the Chomsky hierarchy), but rather "the thing that you but in m/... in Perl".

These regexes are much more powerful than regular expressions, in fact they can do things that even Typ-2 langauges (context-free languages) can't. I've not yet seen a proof that they are Turing complete, so I don't know if they are.

Update: fixed Chomsky classification, thanks jakobi

Perl 6 - links to (nearly) everything that is Perl 6.

In reply to Re^2: check for square-number with a regex by moritz
in thread check for square-number with a regex by Ratazong

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