pglombardo / gist:3884328

Created October 13, 2012


    
    View gist:3884328 
  
  
      gistfile1.rb
    
    
        Raw
      
    
    File suppressed. Click to show.
  
  
            1
            2
            3
            4
            5
            6
            7
            8
            9
            10
            11
            12
            13
            14
            15
            16
            17
            18
            19
            20
            21
            22
            23
            24
            25
            26
            27
            28
            29
            30
            31
            32
            33
            34
            35
            36
            37
            38
            39
            40
            41
            42
            43
            44
            45
            46
            47
            48
            49
            50
            51
            52
            53
            54
            55
            56
            57
            58
            59
            60
            61
            62
            63
            64
            65
            66
            67
          
          
            # Here, I am define a "module" with name Ma. I also define two methods. One without "self."
# and one with. See, later on, what happens when I "include" and what happens when I "extend"
# the "module" within a "class".
#
module Ma
  # I will be able to make this method an instance or a class method of a class.
  # It depends whether I will "include" or "extend" the module in the class.
  # Note that this method, I cannot call it directly on Ma. In order for this method
  # to be useful, I have to include or extend this module within a class.
  #
  def ma_method1
    puts "ma_method1"
  end
 
  # This method, is not reusable, in the sense that I cannot make it be an instance of class
  # method of a class. But still, it is a method of module Ma and I can call it directly.
  #
  def self.ma_method2
    puts "ma_method2"
  end
end
 
puts "Ma responds to ma_method1? : #{Ma.respond_to?(:ma_method1)}" # it will print "false"
puts "Ma responds to ma_method2? : #{Ma.respond_to?(:ma_method2)}" # it will print "true"
puts "-------------"
 
class A
  # "include" sets the module methods as instance methods of the class
  include Ma
end
 
a = A.new
puts "a Responds to ma_method1?: #{a.respond_to?(:ma_method1)}" # it will print "true"
puts "A Responds to ma_method1?: #{A.respond_to?(:ma_method1)}" # it will print "false"
puts "a Responds to ma_method2?: #{a.respond_to?(:ma_method2)}" # it will print "false"
puts "A Responds to ma_method2?: #{A.respond_to?(:ma_method2)}" # it will print "false"
puts "-------------"
 
class B
  # "extend" sets the module methods as class methods of the class
  extend Ma
end
 
b = B.new
puts "b Responds to ma_method1? : #{b.respond_to?(:ma_method1)}" # it will print "false"
puts "B Responds to ma_method1? : #{B.respond_to?(:ma_method1)}" # it will print "true"
puts "b responds to ma_method2? : #{b.respond_to?(:ma_method2)}"  # it will print "false"
puts "B responds to ma_method2? : #{B.respond_to?(:ma_method2)}" # it will print "false"
puts "-------------------"
 
 
module C
  include Ma
end
 
puts "C Responds to ma_method1? : #{C.respond_to?(:ma_method1)}" # it will print "false"
puts "C responds to ma_method2? : #{C.respond_to?(:ma_method2)}" # it will print "false"
puts "-------------------"
 
module D
  extend Ma
end
 
puts "D Responds to ma_method1? : #{D.respond_to?(:ma_method1)}" # it will print "true"
puts "D responds to ma_method2? : #{D.respond_to?(:ma_method2)}" # it will print "false"
puts "-------------------"