From: Rick DeNatale <rick.denatale@...>
Date: 2008-02-13T06:27:04+09:00
Subject: Re: Subclassing Integer; solved!

On 2/12/08, Clifford Heath <no@spam.please.net> wrote:
> Rick DeNatale wrote:
> > I don't think this does what you think:
> ...
> > class Year < Integer
> > end
> >
> > Year.new(2008).class # => Fixnum
> > Year.new(2008) == 2008 # => true
>
> That's exactly what I want. I also want to be able to do
> Year.include module, and Year.new.extend module, adding
> instance variables and methods to both the Year class and
> year instances, and I can't see any other way to do that,
> while maintaining the *appearance* of an integer subclass.
> Can you?

Well this doesn't do it. Using the above code but adding a method to Year.

class Year < Integer
  def foo
  end
end

Year.new(2008).class # => Fixnum
Year.new(2008).foo # =>
# ~> -:18:in `send': undefined method `foo' for 2008:Fixnum (NoMethodError)
# ~> 	from -:18:in `method_missing'
# ~> 	from -:35

The point is that Year.new isn't returning a Year which looks like a
Fixnum, it IS returning a Fixnum.


-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/