Having fun with currencies in Perl 6

currency.p6

enum Currency <EUR USD>;

multi rate(EUR) { 1.252 }
multi rate(USD) { 1.000 }

class Money {
    has Real     $.amount;
    has Currency $.currency;

    method convert_to(Currency $currency) {
        my $self-rate  = rate $.currency;
        my $other-rate = rate $currency;
        my $amount = $.amount * $self-rate / $other-rate;
        Money.new(:$amount, :$currency);
    }

    method Str() {
        "$.amount $.currency"
    }
}

sub postfix:<EUR> { Money.new(:$^amount, :currency(EUR)) }
sub postfix:<USD> { Money.new(:$^amount, :currency(USD)) }

my $money = 1000\ EUR;
say "$money is $money.convert_to(USD)";

Neat!

Awesome idea!

Use BigRat, not Real.