use v5.14;

use strict;
use warnings;

use Data::Dump qw( pp );
use YAML;

sub introspect
{
  my ($data, $output) = @_;
  if (ref $data eq 'ARRAY')
  {
    my $sub_out = ($output->{'ARRAY'} //= {});
    introspect($_, $sub_out) for @{ $data };
  }
  elsif (ref $data eq 'HASH')
  {
    my $hash_out = $output->{"HASH"} //= {};
    for my $key (keys %$data)
    {
      my $sub_out = ($hash_out->{"$key"} //= {});
      introspect($_, $sub_out) for $data->{$key};
    }
  }
  elsif (ref $data)
  {
    $output->{ref($data).'REF'}=1;
  }
  else
  {
    $output->{SCALAR}=1;
  }
}

my @array = ({fname => 'bob',  last_name => 'smith', foo => [\*main]},

             {fname => 'tony', last_name => 'jones', age => 23,
               kids =>
                 [
                   {first_name   => 'cheryl',
                    middle_name => 'karen',
                    age         => 24        },

                   {name         => 'jimmy',
                    age          => 17       }

                 ],
                                                },
             {fname => 'janet', last_name => 'marcos', foo => {},
               occupation => {
                 title => 'trucker',
                 years_on_job => 12}                              },


             {fname => 'Marge', last_name => 'Keefe',
                kids =>
                  [
                    {name => 'kate', age => 7, vaccinated => 'yes'},
                    {name => 'kim', age => 5}
                  ]
             });
             
my %out;

introspect(\@array, \%out);
say pp \%out;
say YAML::Dump(\%out);