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