From: Mark Hubbart <discordantus@...>
Date: 2005-04-15T03:02:47+09:00
Subject: Re: class locals as class methods

On 4/14/05, Trans <transfire@gmail.com> wrote:
> So I find myself once again creating some classes that have
> attributes/state. I have two options, either the class defines
> a class method for the info, or in a superclass I define a method
> that will set that info to a class var when called.
[...]
> as that just feels natural. But then I have to go back and fix
> it, of course. So last night it hits me, why not? Why not have
> class locals define class methods? So in this case, Example C
> would basically be like doing Example A. Yes, I know there's
> namespace overlap, but class locals are rare enough that I don't
> think that's a show stopper. Maybe there are  other problems I'm
> not seeing, perhaps there's some OOP formalism that this rubs the
> wrong way. I don't know. But I've given it more than "15 minutes"
> and it's actually growing on me. Am I crazy?

I think meta-programming would suffer.

# a Foo that is sort of like a Bar
class FooBar < Foo
  bar_methods = Bar.instance_methods - self.instance_methods
  bar_methods.each{ ... }
end

FooBar.bar_methods => ?????

It would be like penalizing people for using metaprogramming techniques :(

Perhaps, if you just want to set attributes:

class Class
  def set(name, value)
    self.class_eval "def self.#{name}() @@#{name} end"
    self.class_eval "@@#{name} = ObjectSpace._id2ref(#{value.object_id})"
  end
end
    ==>nil
class Foo
  set :foo, "yep!"
end
    ==>"yep!"
Foo.foo
    ==>"yep!"

I'm sure it could be condensed even further, if needed.

Off topic now, I thought there was an equivalent of
#instance_variable_set for class variables? It would seem not. I
wonder why.

cheers,
Mark