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Date: Thu, 19 Nov 2009 10:18:47 -0800
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Subject: Re: [PHP-DEV] The inconsistencies/flaws of PHP5's object model
From: stas@zend.com (Stanislav Malyshev)

Hi!

> $methodName)) instead, which is ugly and verbose. Since PHP 5.3 adds 
> closure support, I think the syntax "$o->f()" should also check whether 
> "f" is a closure, if it is, then call it.

That creates a myriad of problems due to the fact that if the class 
defines both __call and __get it is not clear what should happen.

> As PHP is a dynamic language, it might be acceptable to dynamically 
> change the "fixed template" nature of class, especially when programming 
 > PHP in prototype-based way by using class as "object" (which I think is

It might be, but in this particular language it isn't. PHP, unlike 
Javascript, is not a prototype-based language, and the classes are 
common between objects.

> Yes I mean abstract static function here, sorry for my typo. Abstract 
> static function is meaningful: You can force child class to implement 
> it, and combining it with "Late Static Binding" one can implement 
> "Template Method Pattern" in prototype-based way here:

It's kind of complicated to do because unlike the case with objects, 
a::g and c::g are different functions. So what happens if somebody tries 
to call a::g?
You can do that with interfaces though.
Also, the idea of having common base is usually that you expose the base 
class (a) as an API, and then implement it in certain ways which are 
hidden from the client, as he works with base type (a) only. However, in 
this case it obviously can not work, since a::g can't call anything, and 
for calling real name you have to know specific class name.

> <?php
> interface i {
>     static function f();
> }
> class c implements i {
>     public static function f() {
>         echo 'c';
>     }
> }
> function g(i $i) {
>     var_dump($i);
> }
> g('c');
> ?>
> 
> This result is more or less expected since type hinting only works on 
> variable types, and the argument 'c' is a string, but as a type, the 
> interface i cannot hint the fact that class c "is a type of i".

I'm not sure what you are trying to do here, but this code can not work 
- you ask for an object of type i and you pass string. I could guess you 
meant to ask for a name of a class that would implement interface i - 
but that is not supported by the language currently, as class is not an 
object in PHP. You would have to run your own code to do that, e.g. 
using is_subclass_of().
-- 
Stanislav Malyshev, Zend Software Architect
stas@zend.com   http://www.zend.com/
(408)253-8829   MSN: stas@zend.com