Re: Long regexp un multiple lines

Another good place to look for use of the /x modifier is in perlretut. That said the same functionality as in the above stated regular expression could be written more tersely as:

/^(?:[\da-f]{2}:){5}[/da-f]{2}$/
[download]

or with /x

/^(?:
   [/da-f]{2}:
  ){5}
  [/da-f]{2}
 $
/x
[download]

or even shorter if you use qr.

$x = qr/[\da-f]{2}/;
[download]

(and later on)

/^(?:$x:){5}$x$/;
[download]

-enlil

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Re: Re: Long regexp un multiple lines by japhy (Canon) on Apr 22, 2004 at 18:19 UTC
Enlil (et. al.), one of the convenient things about `qr//` is that it returns a self-contained regex. That means your "later on" code can be `/^$x{5}$x$/` It seems weird to me that there's no simpler way to say "pattern X, N times, with pattern Y in between"... you have to write `/^(?:XY){N-1}X$/`. I wonder if there's something in Regexp::Common for that. _____________________________________________________ Jeff`[japhy]`Pinyan: Perl, regex, and perl hacker, who'd like a job (NYC-area) `s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;`	[reply] [d/l] [select]
Re: Re: Re: Long regexp un multiple lines by davido (Cardinal) on Apr 22, 2004 at 20:05 UTC
Actually the reason he had to use the `(?:$x:){5}` approach is because of the colon character that's supposed to delimit each grouping. Your solution leaves that out entirely. Yours will expand to: `/^(?:[\da-f]{2}){5}(?:[\da-f]{2})$/` [download] ...note the missing : colons. Dave	[reply] [d/l] [select]
Re: Re: Re: Re: Long regexp un multiple lines by japhy (Canon) on Apr 22, 2004 at 20:46 UTC
Oh, oops, duh. _____________________________________________________ Jeff`[japhy]`Pinyan: Perl, regex, and perl hacker, who'd like a job (NYC-area) `s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;`	[reply]