From: Trans <transfire@...>
Date: 2008-12-03T05:04:18+09:00
Subject: Re: Class atrr_accessor



On Dec 2, 2:16 pm, Oliver Saunders <oliver.saund...@gmail.com> wrote:
> Why does this not work?

An ideology?

> >> class Foo
> >>   self.class.attr_accessor :baz
> >>   end
>
> TypeError: Foo is not a class
>         from (irb):19

  class Module
    public :attr_accessor
  end

All fixed.

> I understand that the class << self idiom can be used to work around
> this problem but I would like to understand why the above triggers such
> an error and what is meant by it.

Well, I think the idea is that you shouldn't be changing a class'
interface from the "outside" ie. so willy-nilly. So you are required
to go "inside" to get the job done. Sort of a caution barrier. But it
does suck that this requires a second layer, eg. class << self, to get
there. I have tried a private #meta method in the past.

 class Foo
   meta.attr_accessor :baz
 end

which works, though I'm not sure the term "meta" feels quite right.
I've avoided ever using it though because I know others would look at
it and think "what?".

T.