From: Brian Marick <marick@...>
Date: 2001-10-26T12:23:30+09:00
Subject: [ruby-talk:23392] Re: class Foo does not call Class.new?

At 04:32 PM 10/25/01, you wrote:
>No.  But in 1.7.1, I defined something I call "allocation framework",
>which is
>
>   * basically, no "new" overriding (that allows your Class#new trick
>     work in many cases).
>
>   * instance allocation is done by "allocation" method of the class,
>     for example, Array#allocation for arrays.
>
>   * there's a few exceptions remain, for example Class does not call
>     "allocation".

I'm afraid I don't understand. Will I be able to do metaclass tricks? For 
example, my chapter has a series of examples that build on a class IceCream 
that sometimes creates a Celery instance. The first one starts like this:

     class IceCream
       def IceCream.new(starting_licks)
         Celery.new
       end
    end

and I build from there. Then I show how a change to a single method 
(Class#new) lets me have each class count its instances (as shown in my 
original note). That will tie back into the IceCream example.

Will I be able to do equivalent things using the new mechanism?

That's the kind of thing that makes Ruby share the specialness of Smalltalk 
and Lisp: you can accomplish so much with combinations of simple rules. ("A 
class is an object, and new is a method, so let's see what we can do by 
overriding it.")  I'll be sad if I can't do those things, and it will take 
away one of the two big triumphant climaxes from the book.


--
Brian Marick, marick@testing.com
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