From: Robert Klemme <shortcutter@...>
Date: 2009-06-23T05:45:06+09:00
Subject: Re: Some confusion on self and the like....

On 22.06.2009 22:25, Alexander Trauzzi wrote:
> Robert Klemme wrote:
>> On 22.06.2009 21:22, Alexander Trauzzi wrote:
>>
>>> It was recently implemented in PHP as "late static binding" (as "self" 
>>> references the class in which it is used, as opposed to the context 
>>> during the invocation itself).
>> Did you mean "defined" instead of "used"?  Otherwise I cannot make much
>> sense of what you write.
>>
>>> From what I'm reading here, "ruby does it right"(tm?)
>> Yes - of course! :-)
>>
>>> Thanks for all your help guys, I will follow up in a new topic if I have 
>>> any further questions.
>> You're very welcome.
>>
>> Kind regards
>>
>>   robert
> 
> Just to clarify:
> 
> Simple example (language agnostic):
> 
> o Class Animal
>   - Method eat()
> o Class Cat Extends Animal
> 
> 
> In PHP, what would happen is if you used "self" in Animal.eat, it would 
> always resolve the class to be Animal (which is just silly).  PHP seemed 
> to look up against the source file, rather than the inheritance tree.
> Then, in a recent release, they introduced late static binding and a 
> smattering of functions and keywords for it, which opened up the 
> opportunities for classes to reflect on themselves after being extended.

PHP really seems to use "self" for the class and "this" for instances:
http://de3.php.net/manual/en/language.oop5.constants.php

> Its still not perfect, and I can see that Ruby has made more progress in 
> the realm of good OO behaviour.

Ruby was OO from the start on - OO in Perl and PHP were retrofitted.

> Hopefully that helps, just from an academic standpoint ;)

Oh, IMHO this is not just academic.  These are important things to know 
about a programming language.

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/