in reply to Re: Question on Regular Expression
in thread Question on Regular Expression

If I understand the documentation, you can remove eval from there, as it's useless for qr{}.

Well, as far as I can tell, the code the OP posted doesn't make use of the eval feature at all , the code section is a literal

literal 

$ perl -E " $_ = 123; m/\d(?{ warn pos })/"
1 at (re_eval 5) line 1.

$ perl -E " no re qw/eval/; $_ = 123; m/\d(?{ warn pos })/"
1 at (re_eval 5) line 1.

$ perl -E " $_ = 123; $f = qr/\d(?{ warn pos })/; m/$f/;"
1 at (re_eval 5) line 1.

$ perl -E " no re qw/eval/; $_ = 123; $f = qr/\d(?{ warn pos })/; m/$f
+/;"
1 at (re_eval 5) line 1.

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variable aka "dynamic" aka it throws error :) 

$ perl -E " $_ = 123; $f = '(?{ warn pos })';  m/\d$f/; "
Eval-group not allowed at runtime, use re 'eval' in regex m/\d(?{ warn
+ pos })/ at -e line 1.

$ perl -E " $_ = 123; $f = '(?{ warn pos })';  $g = qr/\d$f/; m/$g/"
Eval-group not allowed at runtime, use re 'eval' in regex m/\d(?{ warn
+ pos })/ at -e line 1.

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I believe whatever the OPs real code, he got this error message so he added the "solution"

I also believe there is no need for any of this stuff :) if all the OP is doing is building a data structure, simply match in a loop and use %+ or use Regexp::Grammars

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Re^3: Question on Regular Expression
by sjain (Initiate) on Dec 27, 2014 at 14:17 UTC

    Can you please let me know how to make use of %+ so to match in a loop even if the submatch in a pattern string fails?

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      Can you please let me know how to make use of %+ so to match in a loop even if the submatch in a pattern string fails?

      um, \d always fails :)

      #!/usr/bin/perl --
use strict;
use warnings;
use Data::Dump qw/ dd /;
my $cool = qr/
  (?<key>
      \s*
      (?<key2>\w+)
      \s*
      (?<keyQ>\w+)
      \s*
      (?<NEVER>\d*)
   )
/x;
my $beans = 'castor cocoa coffee pinto navy Mayocoba';

while( $beans =~ m{$cool}g ){
    dd( \%+ );
}
__END__
{
  # tied Tie::Hash::NamedCapture
  key   => "castor cocoa ",
  key2  => "castor",
  keyQ  => "cocoa",
  NEVER => "",
}
{
  # tied Tie::Hash::NamedCapture
  key   => "coffee pinto ",
  key2  => "coffee",
  keyQ  => "pinto",
  NEVER => "",
}
{
  # tied Tie::Hash::NamedCapture
  key   => "navy Mayocoba",
  key2  => "navy",
  keyQ  => "Mayocoba",
  NEVER => "",
}

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[d/l]

        Sorry I couldnt use 'dd' as I got the below error

        Can't locate Data/Dump.pm in @INC (@INC contains: /home/samanth/.cpan/build/File-Monitor-1.00-9nE6lN/lib /home/samanth/.cpan/build/File-Monitor-1.00-9nE6lN/lib /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at ./s5.pl line 5. BEGIN failed--compilation aborted at ./s5.pl line 5.

        if You could provide sample without 'dd' would be muchappreciated.

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