From: Tobias Reif <tobiasreif@...>
Date: 2001-08-11T19:06:17+09:00
Subject: [ruby-talk:19516] Re: the way class variables work

Hi

It seems as if subclasses just extend their parentclasses, but are no
classes themselves. So class variables get overridden by the last
assignment. This is counterintuitive.
David Black's example shows this, and also creates a problem to be
solved, because it has semantic logic:
(generalizations)
A car is a vehicle with 4 tires.
A Bike is a vehikle with 2 tires.
How to implement these circumstances nicely in Ruby, when all subclasses
share class variables with their parents, and override them
'arbitrarily'? Using def initialize? I'm sure a nice solution is
possible, but the behaviour David Black describes is still disturbing.

Tobi

> > Also, can it really be good, from the point of view of code
> > maintenance, for a child class to have the power to change its parent,
> > and all of that parent's other children, including future ones?
> > Doesn't that make things very unstable?
> 
> I would seem so.

-- 
Tobias Reif
http://www.pinkjuice.com/myDigitalProfile.xhtml

go_to('www.ruby-lang.org').get(ruby).play.create.have_fun