BÃRTHÃZI AndrÃs writes:
> Hi,
>
> In Perl5 there can be a flag on a variable, that shows, if it's tainted
> or not. I would like you to ask, if it will be possible the same with
> Perl 6, or - and I'm most interested in this -, if it's possible to
> create something like this by me (defining meta information on
> variables, that not just stored, but has some effect)?
Indeed it is possible. A "property" is allowed to (re)define methods
of the object that it is being applied to, and you're allowed to
MMD dispatch on objects with a certain property.
enum <tainted untainted>;
multi sub infix:<+>(tainted $a, $b) {
(($a but untainted) + $b) but tainted;
}
# ...
my $x = =$*IN but tainted;
my $y = 10;
my $z = $x + $y; # z is now tainted
Luke
