On Nov 2, 2011, at 4:10 AM, David Bruant wrote:
> Another topic:
> -----
> class Monster {
>
> private name, health;
>
> sameName(other) {
> return @name === other@name;
> }
> }
> -----
> I am under this impression that you are accessing the private property
> ("other@name") of an instance which isn't you (other !== this) and I'm not
> sure it's a good idea.
Private names do not leak via reflection, not even via proxies. So what's the
problem?
> Is "other" a monster? (how do you "recognize" a monster from any other
> object?).
You could do ad-hoc type or shape tests. For the example, and even in most
cases in general, there's no need. Duck typing works with private names too.
> If so, is it a good enough reason for you to be able to access its private
> state?
It must be an instance of this class or the name would not be bound.
> If other is not a monster, what is the behavior?
You'd get undefined.
> What happens in the following case?
> -----
> class Monster{
> private health;
>
> constructor(health) {
> @health = health;
> }
> }
>
> let m = new Monster(100);
>
> // pass m to a potentially malicious script:
>
> m.kill = function(){
> @health = 0;
health is not in scope here!
/be
> }
> m.kill();
> -----
> Or, how do you prevent someone who has access to the object to define a
> function which accesses the private state?
> Is the @-syntax only allowed within a class body?
>
> David
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