Marcus Boerger schreef:
Hello Robin,
I checked it out in more detail and it is indeed broken as in it is not
consistent:
[EMAIL PROTECTED] PHP_5_3]$ php -r 'class A { protected static $p=1; } class B extends A
{ protected static $p=2; } ReflectionClass::Export("B");'
-> works == 2 properties
-> but should fail because of changed value
[EMAIL PROTECTED] PHP_5_3]$ php -r 'class A { protected static $p=1; } class B extends A
{ public static $p=2; } ReflectionClass::Export("B");'
Fatal error: Cannot change initial value of property static protected A::$p in
class B in Command line code on line 1
[EMAIL PROTECTED] PHP_5_3]$ php -r 'class A { public static $p=1; } class B extends A {
protected static $p=2; } ReflectionClass::Export("B");'
Fatal error: Access level to B::$p must be public (as in class A) in Command
line code on line 1
[EMAIL PROTECTED] PHP_5_3]$ php -r 'class A { public static $p=1; } class B extends A {
public static $p=2; } ReflectionClass::Export("B");'
-> works == 2 properties
-> but should fail becasue of changed value
So we need to fix this.
I don't get the 'but should fail because of changed value' - isn't the changed
value akin
to overloading a method - where the body of the method changes (obviously)?
I also surmise that the issue becomes more tricky if you consider late static
binding,
which I am assuming is still scheduled for php6, and as such it may be worth
holding back
making a fix until it is clearer what the larger ramifications are?
marcus
Monday, January 28, 2008, 4:18:50 PM, you wrote:
Hi Marcus,
Thanks for the prompt reply and explanation. I have some further
questions though:
If the base class had the property defined as private
then the property is private to that specific class and not directly
accessible by derived classes that is it's name gets prefixed with the class
name.. So in:
class A { private static $p; } class B extends A { private static $p; }
we have two different properties:
Understood. But if we have two separate properties for the reason that
A::$p is not visible to B, then how about these cases?
class A { protected static $p; } class B extends A { protected static $p; }
class A { public static $p; } class B extends A { public static $p; }
In both of those cases, A::$p is visible to the derived class, but the
re-declaration results in A::$p and B::$p being two separate
properties (see pastebin.com/fca2cd5b and pastebin.com/f4f94b32d for a
demonstration). This is one of the reasons I find the case where we
end up with only one property value to be surprising.
Another reason is that, as illustrated in my previous post, PHP's
behaviour doesn't seem to correlate with the inheritance rules of
other languages I'm familiar with: you always end up with two distinct
static properties in Java, C++ and C# (though of course I understand
this fact on its own is does not mean PHP is wrong :).
Lastly, with overridden static methods, PHP always yields two distinct
methods, regardless of the visibility modifiers. See
http://pastebin.com/f27f009c4 . Granted, with methods any other
behaviour would be very odd indeed, but it does emphasize an
inconsistency between method and property inheritance rules in PHP.
So for now I continue to feel this is a little strange. Any further
explanations would be greatly appreciated. :)
Thanks,
Robin
Best regards,
Marcus
Best regards,
Marcus
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