package Enode;

sub new
{
  my $pkg  = shift;
  my $text = shift;                                  #reference to a text
  my $self = {};                                        

  bless $self,$pkg;
 
  if ($$text =~ s/^<([^>]+)>//)                      #finds new xml tag
  {
    my $key = $1;
    $self->{$key} = [];

    unless ($key =~ s/\/\s*$//)                      #is no autoclosing tag
    {
      while ($$text !~ s/<\/[^>]*>)                  #anti tag not found
      {
        push(@{$self->{$key}},(s/^([^>]+)//?new Tnode($1):new Enode($text));        
        #if text is found: textnode is pushed on list, else must be a new xml tag so: elementnode is pushed on list       
      }
    }                                           
    return($self);
  }
}

sub topdown
{
  my $self        = shift;
  my $functionref = shift;

  my $key         = keys %$self;

  &$functionref($self,@_);

  foreach my $node (@{$self->{$key}})
  {
    $node->topdown($functionref,@_);
  }
}

sub bottomup
{
  my $self        = shift;
  my $functionref = shift;

  my $key         = keys %$self;

  foreach my $node (@{$self->{$key}})
  {
    $node->topdown($functionref,@_);
  }

  &$functionref($self,@_);
}

sub strange
{
  my $self        = shift;
  my $functionref = shift;

  my $key         = keys %$self;

  foreach my $node (@{$self->{$key}})
  {
    &$functionref($node,@_);
  }
}