use strict;
use warnings;

sub MyBinTree::insert {
  my ($self,$string,$node)=@_;

  my $ins_ref;
  unless ($node) {
    unless ($self->{root}) {
      $ins_ref=\$self->{root}
    } else {
      $node=$self->{root};
    }
  }
  unless ($ins_ref) {
    if ($string lt $node->{val}) {
      if ($node->{left}) {
        return $self->insert($string,$node->{left})
      } else {
        $ins_ref=\$node->{left};
      }
    } elsif ($string gt $node->{val}) {
      if ($node->{right}) {
        return $self->insert($string,$node->{right})
      } else {
        $ins_ref=\$node->{right};
      }
    } else {
      return $node;
    }
  }
  $$ins_ref={val=>$string,parent=>$node};
  return $$ins_ref
}

sub MyBinTree::new {
  my ($class)=@_;
  my $self= bless { },$class;
  print "Created new $self\n";
  return $self;
}

sub MyBinTree::_traverse {
  my ($self,$node,$sub)=@_;

  if ($node->{left}) {
    $self->_traverse($node->{left},$sub);
  }
  {
    local $_=$node;
    $sub->();
  }
  if ($node->{right}) {
    $self->_traverse($node->{right},$sub);
  }
}

sub MyBinTree::traverse {
  my ($self,$sub)=@_;

  $self->_traverse($self->{root},$sub)
    if $self->{root};
}

sub MyBinTree::DESTROY {
  my $self=shift;
  print "Destroying new $self\n";
  $self->traverse(sub { delete $_->{parent} });
  print "Destroyed\n";
}

{
  my $container=MyBinTree->new();
  $container->insert($_) for (my @words=qw(foo bar baz bop fop cool));
  $container->traverse(sub { print $_->{val},"\n" });
  print "Exiting scope.\n";
}