From: Phrogz <gavin@...>
Date: 2007-04-03T06:35:07+09:00
Subject: Re: New presentation on Ruby

On Apr 2, 3:20 pm, Ilan Berci <code...@yahoo.com> wrote:
> Slide 22) If "top level functions" are "private" methods of class
> Object, there would be no way to call them without a receiver which is
> simply not the case

I think you have that backwards. Private methods *cannot* be called
with an explicit receiver:

  def foo; "bar"; end
  puts Object.private_methods.grep( /foo/ )
  #=> foo
  puts foo
  #=> bar
  puts self.foo
  #=> tmp.rb:4: private method `foo' called for main:Object
(NoMethodError)

  class Foo
    def go1
      secret_word
    end
    def go2
      self.secret_word
    end

    private
      def secret_word
        "bird"
      end
  end

  f = Foo.new
  p f.go1
  #=> "bird"

  p f.go2
  #=> tmp.rb:7:in `go2': private method `secret_word' called for #<Foo:
0x2835584> (NoMethodError)


> Slide 24) Point about attributes only allowed to be defined within their
> class definition is wrong.  In ruby I can define one almost anywhere
> with Object::instance_variable_set or Module::module_eval.
>
> Slide 26) Who are you to say what "private" means.  Each class has their
> own definition and either could be viewed as the truth.  Given that, I
> can still access private methods in a class by going through send() so
> your statement is not correct

IMO both of the above slides are correct. Just because Ruby lets you
do crazy things (break encapsulation by reaching 'inside' via
instance_eval or send) doesn't mean that it doesn't exist and function
well.


> Slide 53) Subjective to the point of insanity..

Now now, be nice :)