From: Francis Cianfrocca <garbagecat10@...>
Date: 2007-05-26T21:14:21+09:00
Subject: Re: Forward references?

------=_Part_37376_23372853.1180181660861
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

On 5/26/07, Peter Seebach <seebs@seebs.net> wrote:
>
>
>         class A::B
>         end
>         class A
>         end
>         --> t.rb:1: uninitialized constant A (NameError)
>
> So I can't just do them in ANY order.



In this construction you're defining B inside the naming context of A, which
doesn't exist when the *parser* (which obeys Ruby scoping rules like any
other Ruby program) needs to use the value of A. That's why I suggested
something like this:

class A
  class B
    def bar
    end
  end
end

class A
  def initialize
    @b = B.new
  end
end


You see the difference? You don't have to define class A before you define
class B, but you DO need to *declare* A before you can present it to Ruby's
parser in a construction like A::xxx.

Of course your original question related to style rather than parser
behavior. You don't say whether you come from a Java background, where the
relationship between classes and source files is much stricter than it is in
Ruby. With closely related Ruby classes like yours, I often define them in
separate text blocks, in the same file:

module MyApplication
    class A
        def initialize
            @b = B.new
        end
    end
end

#------------------------------

module MyApplication
    class A
        class B
        end
    end
end

------=_Part_37376_23372853.1180181660861--