As stevieb points out, the results you get back are objects, and they in turn contain other objects. The docs are a bit scattered, but the result objects are either a list with a get_next() method, or they represent a host, port, service etc. and have relevant access methods. From the code you posted I think this should achieve the same thing (untested): 
my $results = $scanner->scan();
 
my $host_list = $results->get_host_list;
 
while ( my $host = $host_list->get_next ) {
    my $port_list = $host->get_tcp_port_list;
    my %report;
    while ( my $number = $port_list->get_next ) {
        my $port = $host->get_tcp_port( $number );
        $report{ $port->service->name } = $port->state;
    }
}

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In reply to Re: Parsing output from Nmap::Scanner with varying hash address. by tangent
in thread Parsing output from Nmap::Scanner with varying hash address. by mopmeat

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