css4.pl

use Mojo::DOM;

# Parse HTML5 snippet
my $dom = Mojo::DOM->new(<<EOF);
<div>
  <a href="http://search.cpan.org">
    <img src="/images/search.png">
  </a>
  <a href="http://mojolicio.us">
    <p>Mojolicious</p>
  </a>
  <a href="http://metacpan.org">
    <p><img src="/images/metacpan.png"></p>
  </a>
</div>
EOF

# Add class attribute to all image links
$dom->find('$a img')->each(sub { shift->{class} = 'logo' });

# Render HTML5 snippet
print "$dom";

Whats the reason you are using the dollar-sign instead of the exclamation mark like in the w3c proposal? Wouldn't it be saner to stay standard-compliant?