regx expression? (link included)

[werwer]

A favor please . Would someone tell me if this regx requires
something I don't have installed? I copied it, but it will not
compile. I've never seen a regx written like this and I kind of
wonder if this is input to some other parser. Thanks. (perk 5,8,8)

Here's the link. (I pasted a copy below also, but I'm never sure if
it's readable or not)

http://www.perlmonks.org/?node_id=603809


my $email_address = qr {
(?(DEFINE)
(?<addr_spec> (?&local_part) \@ (?&domain))
(?<local_part> (?&dot_atom) | (?&quoted_string))
(?<domain> (?&dot_atom) | (?&domain_literal))
(?<domain_literal> (?&CFWS)? \[ (?: (?&FWS)? (?&dcontent))* (?
&FWS)?
\] (?&CFWS)?)
(?<dcontent> (?&dtext) | (?&quoted_pair))
(?<dtext> (?&NO_WS_CTL) | [\x21-\x5a\x5e-\x7e])

(?<atext> (?&ALPHA) | (?&DIGIT) | [!#\$%&'*+-/=?
^_`{|}~])
(?<atom> (?&CFWS)? (?&atext)+ (?&CFWS)?)
(?<dot_atom> (?&CFWS)? (?&dot_atom_text) (?&CFWS)?)
(?<dot_atom_text> (?&atext)+ (?: \. (?&atext)+)*)

(?<text> [\x01-\x09\x0b\x0c\x0e-\x7f])
(?<quoted_pair> \\ (?&text))

(?<qtext> (?&NO_WS_CTL) | [\x21\x23-\x5b\x5d-\x7e])
(?<qcontent> (?&qtext) | (?&quoted_pair))
(?<quoted_string> (?&CFWS)? (?&DQUOTE) (??&FWS)? (?
&qcontent))*
(?&FWS)? (?&DQUOTE) (?&CFWS)?)

(?<word> (?&atom) | (?&quoted_string))
(?<phrase> (?&word)+)

# Folding white space
(?<FWS> (?: (?&WSP)* (?&CRLF))? (?&WSP)+)
(?<ctext> (?&NO_WS_CTL) | [\x21-\x27\x2a-\x5b\x5d-
\x7e])
(?<ccontent> (?&ctext) | (?&quoted_pair) | (?&comment))
(?<comment> \( (?: (?&FWS)? (?&ccontent))* (?&FWS)? \) )
(?<CFWS> (?: (?&FWS)? (?&comment))*
(?: (??&FWS)? (?&comment)) | (?&FWS)))

# No whitespace control
(?<NO_WS_CTL> [\x01-\x08\x0b\x0c\x0e-\x1f\x7f])

(?<ALPHA> [A-Za-z])
(?<DIGIT> [0-9])
(?<CRLF> \x0d \x0a)
(?<DQUOTE> ")
(?<WSP> [\x20\x09])
)

(?&addr_spec)
}x;

 

[Ben Morrow]

A favor please . Would someone tell me if this regx requires
something I don't have installed? I copied it, but it will not
compile. I've never seen a regx written like this and I kind of
wonder if this is input to some other parser. Thanks. (perk 5,8,8)

my $email_address = qr {
(?(DEFINE)
(?<addr_spec> (?&local_part) \@ (?&domain))

Kind-of: this regex is pretty much a demonstration of the new features
in the 5.10 regex engine. So, you would need perl 5.10.0 or later to use
it.

Ben

 

[Brian McCauley]

...this regex is pretty much a demonstration of the new features
in the 5.10 regex engine. So, you would need perl 5.10.0 or later to
use it.

Of course, one of the new features in 5.10 is the pluggable regex
engine, so in principle you _will_ be able to use features from the
5.11/5.12 regexes in 5.10!