gistfile1.pl

package Roman;
use Moose;

sub AUTOLOAD {
    our $AUTOLOAD;

    (my $digits = $AUTOLOAD) =~ s/.+:://g;
    $digits =~ s/$_->[0]/$_->[1]/
        for
            [ IV => 'IIII'  ],
            [ IX => 'VIIII' ],
            [ XL => 'XXXX'  ],
            [ XC => 'LXXXX' ];

    return $_[0]->_count(reverse split(//, $digits));
}

sub _count {
    my ( $class, $head, @tail ) = @_;
    return 0 unless defined $head;
    return
        { I => 1, V => 5, X => 10, L => 50, C => 100 }->{ $head } +
        $class->_count( @tail )
}

warn Roman->IX;