ruby private class method helper

Question

Hi I am trying to create a helper for mass defining ruby methods as private class methods. In general one can define a method as a private class method by using private_class_method key work. But I would like to create a helper in the following style:

class Person
  define_private_class_methods do 
    def method_one
    end

    def method_two
    end
  end
end

The way I planned to dynamically define this is in the following way, which is not at all working:

class Object
  def self.define_private_class_methods &block
    instance_eval do
      private
      &block
    end
  end
end

any ideas where I might be going wrong?

Answer 1

$ cat /tmp/a.rb

class Object
  def self.define_private_class_methods &cb
    existing = methods(false)
    instance_eval &cb
    (methods(false) - existing).each { |m| singleton_class.send :private, m }
  end
end

class Person
  define_private_class_methods do 
    def method_one
            puts "¡Yay!"
    end
  end
end

Person.send(:method_one)
Person.public_send(:method_one)

$ ruby /tmp/a.rb

¡Yay!

/tmp/a.rb:18:in `public_send': private method `method_one' 
                 called for Person:Class (NoMethodError)
Did you mean?  method
    from /tmp/a.rb:18:in `<main>'

Please note, that it’s hard to understand, what you are trying to achieve and possibly there is better, cleaner and more robust way to achieve this functionality.