Ruby Inheritance/Macro Example

ruby-inheritance-macro-example.rb

class Person
  attr_accessor :name
  def self.can_speak  # This is a class method! Notice the self.
    define_method 'speak' do  # an instance method
      puts "I can talk, my name is #{@name}!"
    end
  end

  def initialize(name)
    @name = name
  end
end

class Guy < Person
  can_speak
end

class ShyGuy < Person
end

john = Guy.new('John')
bob = ShyGuy.new('Bob')
john.methods.include?(:speak)   # true
bob.methods.include?(:speak)    # false