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If any of those take the value of the attribute outside it's defined range, then no, I don't want it to "Just work". I want it to "Just NOT work".

Most of the time, this isn't needed. A normal variable $foo can have any value and I don't understand why instance variables should be different in this.

Still, because value validation is a nice thing to have, tie with a STORE handler isn't a bad idea. But this shouldn't be specific to OO - the solution should apply to all variables. Our implementation, however, cheats by ignoring normal variables. This was easier :)

sub foo : Property { $_ < 10 } main->foo = 9; main->foo++; # dies

Perl 6 will provide a real solution, with a nice syntax even! In fact, more than one nice syntax!

has $foo where { $_ < 10 };
This extends to non-instance variables too. Just use "our" or "my" instead of "has".
my $foo where { $_ < 10 }; $foo = 9; $foo++; # dies

Juerd # { site => 'juerd.nl', plp_site => 'plp.juerd.nl', do_not_use => 'spamtrap' }


In reply to Re^7: Experimenting with Lvalue Subs by Juerd
in thread Experimenting with Lvalue Subs by Limbic~Region

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