On 5/25/2016 9:13 PM, Niklas Keller wrote: > 2016-05-25 20:39 GMT+02:00 Fleshgrinder <p...@fleshgrinder.com>: > >> In my opinion it should simply vanish along with its definition. I mean, >> > > Usually, yes. But suddenly `private Type $foo` isn't reliable anymore if > unset is supported for typed properties, because the following would just > remove all type info / enforcement: > > $backup = $this->foo; > unset($this->foo); > $this->foo = $backup; > > Unset can reset it to the default value, but wiping type information is > probably > not an option here. > > Regards, Niklas >
I had to check because I never tried this once in my life (why would one
need it anyways) ...
class A {
private $foo = "foo";
function get() {
return $this->foo;
}
function unset() {
unset($this->foo);
}
}
$a = new A;
echo $a->get(); // foo
$a->unset();
echo $a->get(); // Notice: Undefined property: A::$foo
$a->foo = "foo";
// Fatal error: Uncaught Error: Cannot access private property A::$foo
In other words, unset is not really unset already!
QED: Preserving *all* attributes of a property is the only consistent
way. However, preserving its value is not.
I do not think that there is a problem together with the typed
properties, nullability, and unset simply because the property is not
explicitly assigned null by unset, it is being undefined.
I think internally null is actually assigned and it's not IS_UNDEF,
right? However, from a userland perspective it is definitely not defined
anymore and access should (as it does) result in an error (in our case
E_INFO) plus null is being returned but only because undefined does not
exist in PHP userland.
I did not read up on all the history yet but I am on it ...
--
Richard "Fleshgrinder" Fussenegger
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