From: Robert Klemme <bob.news@...>
Date: 2005-04-09T00:19:42+09:00
Subject: Re: [EVALUATION] - E03b - The Ruby Object Model


"Csaba Henk" <csaba@phony_for_avoiding_spam.org> schrieb im Newsbeitrag
news:slrnd5d5vm.crg.csaba@ms0.math.ucalgary.ca...
> On 2005-04-05, Lionel Thiry <lthiryidontwantspam@skynetnospam.be> wrote:
> > Most of the time, everything goes in ruby as if there weren't any kind
of
> > metaclasses. For exemple, you cannot explicitely create your own
metaclasses:
> >
> > class MyMetaClass < Class
> > end
> >
> > It raises the exception:
> > metaclass.rb:1: can't make subclass of Class (TypeError)
>
> Hmm, the rigor of the interpreter here is somewhat loose. You can
> subclass Class, just not as you tried.
>
> MyMetaClass = Class.new Class
> MyMetaClass.ancestors
>  # => [MyMetaClass, Class, Module, Object, Kernel]
>
> This works just fine. However, it's not too consistent altogether...

The question is, what does one gain by subclassing Class?  You cannot
create instances (i.e. classes) of it:

>> Foo = MyMetaClass.new
TypeError: wrong instance allocation
        from (irb):5:in `new'
        from (irb):5
>> Foo = MyMetaClass.allocate
TypeError: wrong instance allocation
        from (irb):6:in `allocate'
        from (irb):6

Cheers

    robert