sub foo
{
     my ($foobar, $frurab) = @_;
     my @foo = split(/,/, $foobar);
     my $bar;
     my $x;

     foreach $x (@$frurab)
     {
           $bar .= $x->foo();
     }

     foreach $x (@foo)
     {
           $bar = "<$x>$bar</$x>";
     }

     return $bar;
}