#!/usr/bin/perl

use strict;
use warnings;

use XML::Rules;

my @rules = (
  _default => sub {$_[0] => $_[1]->{_content}},
  query =>    sub { print "$_[1]->{name}: $_[1]->{topN}\n" },
);
my $r = XML::Rules->new(rules => \@rules);
$r->parse(\*DATA);

__END__
<?xml version='1.0'?>
<queries>
    <query>
        <name>topHosts</name>
        <layer>LINK</layer>
        <topN>20</topN>
        <datatype>topHosts</datatype>
        <filter></filter>
    </query>
    <query>
        <name>topHosts</name>
        <layer>LINK</layer>
        <topN>120</topN>
        <datatype>topHosts</datatype>
        <filter></filter>
    </query>
</queries>