#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper qw/Dumper/;
use Perl6::Say;
use Tree::Simple;

my $tree = Tree::Simple->new("0", Tree::Simple->ROOT);
my $sub_tree = $tree->addChild(Tree::Simple->new("1"));
$sub_tree->addChildren(
	Tree::Simple->new("2.1"),
	Tree::Simple->new("2.2")
);

say $tree->getChild("2.1")->getNodeValue();
say $tree->getChild("2.2")->getNodeValue();

print $tree->getChild(1)->getNodeValue();
print $tree->getChild(2)->getNodeValue();

sub find
{
  my $tree = shift;
  my $node_value=shift;
  my $last=0;
  my $child;
  my $func;
  $func = sub ($)
  {
    $child=shift();
    $last=1 if($child->getNodeValue() eq $node_value);
    my @children=$child->getAllChildren();
    $func->(shift(@children)) while(@children && !$last);
  };
  $func->($tree);
  return $child if($last);
  return undef;
}

my $node = find($tree,"<NodeValue>")

sub hash_nodes
{
  my $tree=shift;
  my %h=();
  my $sub;
  $sub = sub ($)
  {
    my $node=shift;
    my $value=$node->getNodeValue();
    push(@{$h{$value}},$node);
  };
  $tree->traverse($sub);
  return %h;
}

%index=hash_nodes($tree);
$node=$index{"<NodeValue>"}[0];

sub find
{
  my $tree = shift;
  my $node_value=shift;
  my @childs=();
  my $func;
  $func = sub ($)
  {
    my $child=shift();
    push(@childs,$child) if($child->getNodeValue() eq $node_value);
    my @children=$child->getAllChildren();
    $func->(shift(@children)) while(@children);
  };
  $func->($tree);
  return @childs;
}

my @nodes=find($tree,"<NodeValue>");