OK, I buy that, I think. But does that mean that fixing edge cases in your arguments doesn't work at all, i.e. you can't even do this?
sub foo(?$x) { $x //= 1; # if they passed an undef, init it to 1 ... }
That's right. It's an error. You need:
sub foo(?$x is copy) {
$x //= 1; # if they passed an undef, init it to 1
...
}or that you have to say it like this?
sub foo(?$x) { my $x = $x // 1; # hide $x param using a non-const C<my>? ... }
That won't work either, since the name of the lexical variable C<$x> is introduced immediately in Perl 6, so the C<$x> on the lhs is the lexical one from the rhs, not the parameter.
Damian
