http://www.perlmonks.org?node_id=1055870


in reply to Named capture backreferences cannot be used in character classes?

One workaround is to use a negative look-ahead plus a dot instead of a negated character class: 

use strict;
use warnings;
use 5.010;

for (qw/'abc' "abc" 'abc"/) {
    if (/(?<FQ>['"])(?<content>(?:(?!\k<FQ>).)+)\k<FQ>/s) {
        say $+{content};
    }
    else {
        say "Not matched: $_";
    }
}
__END__
abc
abc
Not matched: 'abc"

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Re^2: Named capture backreferences cannot be used in character classes?
by BrowserUk (Patriarch) on Sep 26, 2013 at 17:45 UTC

    Perfect. Thank you.

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    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
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Re^2: Named capture backreferences cannot be used in character classes?
by Anonymous Monk on Sep 26, 2013 at 22:49 UTC

    Probably not worth it, but fewer negative look-aheads:

    my $re = qr/
  (?<FQ>['"])         # Capture starting quote.
  (?<content>         # Capture content.
    (?:
      (?>[^'"]*)      # Match non-quotes, don't backtrack.
      (?(?!\k<FQ>).)  # Match opposite quote.
    )*                # Repeat.
  )
  \k<FQ>              # Match ending quote.
/x;

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