From: Robert Klemme <bob.news@...>
Date: 2005-09-27T17:56:42+09:00
Subject: Re: How each class splats

Devin Mullins wrote:
> Robert Klemme wrote:
> 
>> Devin Mullins wrote:
>> 
>> 
>>> But I think your best bet is define your own Collection object with
>>> its own #each.
>>> 
>>> 
>> I though so, too, but it doesn't help:
>> <snip>
>> 
>> 
> Oooh... not what I meant. :) I meant something like this:
> 
> class B
>   attr_reader :i, :v
>   def initialize(i,v)
>     @i, @v = i, v
>   end
> end
> 
> class ArrayOfB < DelegateClass(Array)
>   def each
>     super { |b| yield b.i, b.v }
>   end
> end
> 
> a = ArrayOfB.new [B.new(:a, 1), B.new(:b, 2)]
> a.each { |i, v| puts "i = #{i.inspect}, v = #{v.inspect}" }

Interesting.  Why does it work?  Which method does the trick here?

>> a.class
=> ArrayOfB
>> a.class.ancestors
=> [ArrayOfB, #<Class:0x1017cc00>, Object, Kernel]
>> a.kind_of? Array
=> false
>> Array === a
=> false

Hm...

Kind regards

    robert