From: Rick DeNatale <rick.denatale@...>
Date: 2010-05-05T01:49:32+09:00
Subject: Re: Scope

On Tue, May 4, 2010 at 9:55 AM, Eduardo Mucelli R. Oliveira
<edumucelli@gmail.com> wrote:
> I have a script with those two following classes:
>
> class String
>   def to_b
>      ["true"].include?(self.downcase)
>   end
> end

This opens up the system class String (or ::String if you prefer to
explicitly specify the outer scope) and adds an instance method
available to any instance of ::String

>
> class HereIWantUseToB
>   "string".to_b
> end
>
> Ok,  that works fine, the to_b method can be "seen" by
> HereIWantToUseToB class. But I wanted to those two classes inside
> another class, or module, like this:
>
> class Everything
>   # The two classes described above are here
> end
>
> module Everything
>   # The two classes described above are here
> end


Either

class Everything
  class String
     #...
  end
end

or

module Everything
  class String
     #...
  end
end

creates a new class Everything::String, which is unrelated to ::String


> Anyway, for both cases I have the message "NoMethodError: undefined
> method `to_b’ for string." What is the scope point in here,

A string literal, like "string', or "foo" will ALWAYS be an instance
of ::String, and never an instance of Everything::String



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Rick DeNatale

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