From: "Jan E." <lists@...>
Date: 2012-03-30T22:12:36+09:00
Subject: Re: Why z = Complex(1,2) rather than z = Complex.new(1,2)?

Robert Klemme wrote in post #1054170:
> Do you get that at the calling site or at the definition site?

I get the message when I define the method.



Robert Klemme wrote in post #1054170:
> Jan E. wrote in post #1054047:
>> Another problem is that constants and methods have different lookup
>> algorithms, which doesn't allow you to put the conversion method for a
>> subclass into the same containing module/class (unless you use qualified
>> names all the time).
>
> Can you show an example of what you cannot do?  At the moment I don't
> see the limitation.

As long as you're on top level, you can define a class and the 
corresponding method on the same level:

####
A = Class.new
def A()
  A.new
end

p A
p A()
####

But when the class is inside a module, you cannot define the method in 
this module and access it in the same way as you access the class:

####
module M
  A = Class.new
  def self.A()
    A.new
  end

  class B
    def test
      p A    # this works
      p A()  # this doesn't
    end
  end
end

b = M::B.new
b.test
####

Of course, there's nothing strange about this behaviour. Methods simply 
cannot access "outer methods". But in this context, I find the different 
lookup algorithms counterintutive. You'd have to qualify the method name 
or define it in a different place (like the top level).



Robert Klemme wrote in post #1054170:
> There are far worse "warts" as you call them, for example class
> variables.

Sure.

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