use 5.012;
use strict;
use warnings;

use Ask qw(:all);
use XML::LibXML 2;

my $xml = XML::LibXML->load_xml(IO => \*DATA);
my $who = entry("Who are you looking for?");

my ($person) = $xml->findnodes(qq{//person[name/text() = "$who"]})
	or error("Cannot find '$who'\n") and die;

my @lines = $person->findnodes(qq{adr/*})->map(sub { $_->textContent });
info(join "; ", @lines);

__DATA__
<contacts>
	<person>
		<name>Barack Obama</name>
		<adr>
			<street-address>1600 Pennsylvania Avenue Northwest</street-address>
			<locality>Washington</locality>
			<region>DC</region>
			<postal-code>20500</postal-code>
			<country>United States</country>
		</adr>
	</person>
	<person>
		<name>David Cameron</name>
		<adr>
			<street-address>10 Downing Street</street-address>
			<locality>London</locality>
			<postal-code>SW1A 2AA</postal-code>
			<country>United Kingdom</country>
		</adr>
	</person>
</contacts>