{
package bin_tree;
use strict;
use warnings;

sub new{
    my $class=shift;
    my $self={value=>undef, a=>undef, b=>undef}; #make our object as an anonymous hash with keywords but no values yet, that way the a an
    $self->{value}=0;
    bless $self, $class; #make object
    return $self; #return object
}
sub populate{
    my($self, $depth)=@_;
    return if(! $depth);

    $self->{a} = populate( bin_tree->new() , $depth -1 );
    $self->{b} = populate( bin_tree->new() , $depth -1 );
    return $self;
}
1;
} #end bin_tree

package main;
use strict;
use warnings;

#try to create a three node deep binary tree
my $bintree = bin_tree->new();
$bintree->populate(3);
use Data::Dumper;
print Dumper $bintree;