Named Tuple in Raku

namedtuple

class Tuple does Positional {
    has $.a;
    has $.b;

    multi method AT-POS(0) {
        $!a;
    }
    multi method AT-POS(1) {
        $!b;
    }

    multi method COERCE(@i) {
        self.new(a => @i[0], b => @i[1]);
    }

}
sub namedtuple(Str $class, Str $a, Str $b --> Mu) {
     my $type := Metamodel::ClassHOW.new_type(name => $class);
     $type.^add_parent(Tuple);
     $type.^add_method($a, method () { self.a });
     $type.^add_method($b, method () { self.b });
     $type.^compose;
     $type;

}

constant Point = namedtuple('Point', 'x', 'y');

my $p = Point(1,2);

say $p.x;
say $p[0];
say $p.y;
say $p[1];