reg-ex pattern with nesting parethesis

marscld has asked for the wisdom of the Perl Monks concerning the following question:

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Re: reg-ex pattern with nesting parethesis by choroba (Cardinal) on Jun 11, 2014 at 09:21 UTC
The rule is easy: However you nest the capture groups, the numbers correspond to the order of the opening parentheses. لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply]
Re: reg-ex pattern with nesting parethesis by AppleFritter (Vicar) on Jun 11, 2014 at 09:13 UTC
`$1` and `$2` refer to the first and second captures, respectively: in this case, `$1` corresponds to the entire regex, while `$2` refers to just the `\d+`. What they'll actually contain depends on what's in `$_`, of course.	[reply]
Re^2: reg-ex pattern with nesting parethesis by marscld (Beadle) on Jun 11, 2014 at 09:22 UTC
In this case, out most parenthesis would be matched first, then for nested ones. Thanks for clarification, AppleFritter.	[reply]
Re: reg-ex pattern with nesting parethesis by Corion (Patriarch) on Jun 11, 2014 at 09:16 UTC
See perlretut and perlre for the official documentation on this	[reply]
Re^2: reg-ex pattern with nesting parethesis by AnomalousMonk (Archbishop) on Jun 11, 2014 at 09:45 UTC
In particular, take a look at Capture groups in perlre and Extracting matches in perlretut.	[reply]
Re^3: reg-ex pattern with nesting parethesis by Anonymous Monk on Jun 11, 2014 at 10:00 UTC
perlintro#Parentheses for capturing and perlrequick#Extracting matches and Re^3: My Favourite Regex Tools (Was: Parsing a Variable Format String) Read more... (8 kB)	[reply]
Re: reg-ex pattern with nesting parethesis by LanX (Saint) on Jun 11, 2014 at 09:41 UTC
See also Re: how to extract string by possible groupings? HTH! :) Cheers Rolf (addicted to the Perl Programming Language)	[reply]