Show closure variables of a subroutine

sub-closure-vars.pl

# PadWalker

use warnings;
use strict;

use PadWalker;

my $a = "A";
my $b = "B";

my $sub1 = do {
  my $c = "C";
  my $d = "D";
  sub {
      my $e = "E";
      print "SUB1", $a," AND ",$c;
  }
};

my $sub2 = sub {
  my $f = "F";
  print "SUB2", $a, " AND ", $f;
};

sub sub3 {
  my $g = "G";
  print "SUB3", $a, " AND ", $g;
}

my $hash_1 = PadWalker::closed_over($sub1);
my $hash_2 = PadWalker::closed_over($sub2);
my $hash_3 = PadWalker::closed_over(\&sub3);

require Data::Dumper;
$Data::Dumper::Terse = 1;

print "SUB1 : \n", Data::Dumper::Dumper($hash_1);
print "SUB2 : \n", Data::Dumper::Dumper($hash_2);
print "SUB3 : \n", Data::Dumper::Dumper($hash_3);

__END__
# ---------------------- result --------------------------- #
=begin result
SUB1 : 
{
  '$c' => \'C',
  '$a' => \'A'
}
SUB2 : 
{
  '$a' => \'A'
}
SUB3 : 
{
  '$a' => \'A'
}
=end result
=cut