Example

gistfile1.rb

class Animal                                                         
  def initialize(species)                                            
    @species = species                                               
  end                                                                
                                                                     
  def species                                                        
    @species                                                         
  end                                                                
end                                                                  
                                                                     
class Animal                                                         
  def self.property(name)                                            
    define_method(name) do                                           
      puts "Animal has a #{name} property"                           
    end                                                              
  end                                                                
                                                                     
  property :tail                                                     
end                                                                  
                                                                     
animal = Animal.new("cat")                                           
puts "Animal is a #{animal.species}"                                 
animal.tail