From: m4dc4p <jgbailey@...>
Date: 2005-10-08T06:16:50+09:00
Subject: Re: newb: Class Method determining it's actual class?

It's like lighting a cigarette while waiting for the bus. Nothing
guarantees faster arrival, haha!

Art Gillespie wrote:
> Hi again,
>
> There must be some law somewhere says that the chances of finding the
> answer yourself goes up exponentially in the moments after posting to
> a mailing list.
>
> I hadn't even thought to try 'self' in a class method.  Much to learn.
>
> Thanks again,
>
> Art
>
> On 10/7/05, Art Gillespie <agillesp@gmail.com> wrote:
> > Hi,
> >
> > New to Ruby and to the list.  I've looked through pickaxe and through
> > the ruby source code and haven't figured this one out.
> >
> > With the built-in File class, if I derive from it and call a class
> > method (e.g., open) what I get back is an instance of my derived
> > class:
> >
> > class IFFFile < File
> > end
> >
> > f = IFFFile.open("media.iff", "r")
> >
> > f.class => "IFFFile"
> >
> > How does one do this with their own class methods?
> >
> > class A
> >   def A.open
> >     #how do we know here if the message recipient is a subclass of A?
> >     #i.e., can't we generalize it so that it is, in effect, class.new?
> >     A.new
> >   end
> > end
> >
> > Many thanks for any pointers to what I'm missing.
> >
> > Art
> >
> >