From: Antti Karanta <Antti.Karanta@...>
Date: 2006-01-03T03:22:57+09:00
Subject: A question about Ruby main object



                        Hi!

  I have been doing different things w/ Ruby for a couple of years now and
the only bad thing I can say about it is that it makes programming in other
languages feel awfully burdensome. = )

  Anyhow, I really like how everything makes sense. There is one thing that
I have not been able to fit in entirely. A Ruby program starts in the
context of the "main" object, 

antti@hyperion:~> ruby -e "puts self"
main
antti@hyperion:~> ruby -e "puts self.class"
Object

  However, the methods I declare in the context of this "main" object are
somehow available as private methods of class Object (and naturally usable
from subclasses):

def foo
  puts "hello"
end
class Bar
  def amethod
    foo
  end
end
b = Bar.new
b.amethod

  outputs:
hello

  Is there some logical explanation for this? I understand that this is very
convenient as these methods appear as "stand-alone functions", but taking
it just as "it just is so" breaks the otherwise consistent rules, as
normally you have to define a method in the context of a class for it to be
a method of that class. However, the "main" object is not class Object, nor
is it a class at all:

antti@hyperion:~> ruby -e "puts self.kind_of?(Class)"
false
antti@hyperion:~> ruby -e "puts self.kind_of?(Module)"
false

  So what is the logic behind the "main" object? Is there a logical reason
for the methods defined in its context to appear as private methods of
class Object?



        -Antti-