From: Lionel Thiry <lthiryidontwantspam@...>
Date: 2005-04-20T07:19:38+09:00
Subject: Re: - E03c - The Ruby Object Model (Revised Documentation)

Ilias Lazaridis a �crit :
> Lionel Thiry wrote:
> 
>> Ilias Lazaridis a �crit :
>>> But as it looks, this community is incapable to do so (giving 
>>> productive feedback).
>>
>>
>> I can.
>>
>> -
>>
>> But there are other ways of asking, you know... :(
> 
> 
> there are other ways of answering, too.

You're right! :)

Then change your way of asking, and I bet people will change their ways of 
anwsering! :)

>> I'll give it a try: the documentation "ri Class" gives is not wrong at 
>> all. Maybe not complete, but not wrong.
> it's incomplete, wrong and missleading.

I may seem to ask a bit too much of you, but, would you mind explain where it is 
wrong?

>> I remember that what was disturbing you was the stuff about 
>> metaclasses. I told you ruby invite you to think more in terms of 
>> singleton method than in terms of metaclasses. But it seems that you 
>> ignore what are singleton methods.
> 
> of course i ignore them.
> 
> they are not relevant when reviewing ruby's oject-model.
> 

If you knew about singleton methods, the said metaclasses would not have been 
such a source of confusion for you.

>> http://lazaridis.com/case/lang/ruby/TheRubyObjectModel.png
>>
>> Your UML diagram of ruby object model is hard to read, and probably 
>> wrong. The separation between classes in memory and in source code is 
>> totally confusing. 
> 
> 
> the seperation exist in reality (and in the "ri class" documentation).
> 
> additionally: It was neccessary for my understanding process.
> 
> the next version (1.1), the diagramm will be simplified (possibly in a 
> few hours, if the stuff has passed).
> 
>> In ruby, classes *are* objects. 
> 
> 
> yes, but there is still a class definition.

In fact, not even. In java or C++, they are processed during compilation, not 
during execution. In ruby, those "declarations" are really processed during 
execution. So, they look like declarations, but they are not: they are 
instructions. Hence I told you that separation in your UML diagram is a source 
of confusion.

> 
>> Learn more about classless languages, and it should be far easier to 
>> understand these concepts.
> 
> 
> this is not relevant to understand ruby's Object Model.

But this would help you so much!

> 
> I just need a (correct) UML diagram to understand Ruby's Object Model.
> 
>>
>> There is another evident mistake in your UML diagram. Object doesn't 
>> inherit from nil, nil is a literal and an instance of NilClass which 
>> inherit from Object.
> 
> 
> you are wrong:

By the way, you should never say to someone "you are wrong". Prefer to say "If 
you are right, then, I don't understand this". Doing things that way, you'd 
avoid a lot of flaming.

> 
> irb(main):001:0> Object.superclass
> => nil
> irb(main):002:0> nil.class
> => NilClass
> 

irb(main):001:0> Object < nil.class
=> false
irb(main):002:0> Object > nil.class
=> true

-- 
Lionel Thiry

Personal website: http://users.skynet.be/lthiry/