From: Pete <pertl@...>
Date: 2006-06-07T04:49:19+09:00
Subject: Re: Instance methods can't call protected class methods?

where's the problem?

class Test

  protected
    def self.call_me
      puts "static and protected"
    end

  public
    def invoke_me
      puts "try to call"
      Test.call_me
      # this will _not_ work: self.call_me
      puts "done"
    end

end

t = Test.new
t.invoke_me


 > try to call
 > static and protected
 > done



Sean Hermany schrieb:
> I am trying to understand this behavior.
>
> >From page 356 of the Pickaxe (2nd ed):
>
> Protected. Can be invoked only by objects of the defining class and its 
> subclasses.
>
> If I have
>
> class Foo
> ...
> end
>
> f = Foo.new
>
> Is f not an "object of the defining class"? If so, why should an 
> instance method of Foo not be able to call a protected class method?
>
> I'm not looking for an answer of the form "because in class scope, 
> self.class.type.object.class # => Object, however in *instance* scope" 
> etc. Logically, why should it be this way?
>
> In C++ it makes sense that a static class method cannot call an 
> non-static method, since static methods exist even when there are no 
> objects of the class in existence. However, they do not limit you on the 
> reverse and prevent a non-static method from calling a static method.
>
>