#Learning Ruby chapter 9

#single inheritance
#modules = interfaces from Java
class Hello
  def initialize( name )
    @name = name
  end
  
  def hello_world
    puts "1 Hello, " + @name + "!"
  end  
end

hi = Hello.new( "world" )
hi.hello_world

#you can always add to a class, they are always open
class Array
  def array_of_ten
    (1..10).to_a
  end
end

a = Array.new
ten = a.array_of_ten
puts "2 #{ten.inspect}"

#getters and setters
class Horse
  def name #getter
    @name
  end
  
  def name=( value ) #setter
    @name = value
  end
end

h = Horse.new
h.name = "Jimbo" #set
puts "3 #{h.name}" #get

#each class works with the Module named class
#this makes available attr , attr_reader , attr_writer , and attr_accessor
class Dog
  attr :bark , true
end

class Dog2
  attr :bark
end


puts "4 #{(Dog.instance_methods - Object.instance_methods).inspect}"
puts "5 #{(Dog2.instance_methods - Object.instance_methods).inspect}"

fido = Dog.new
fido.bark = "woof!"
puts "6 #{fido.bark}"


class Dog3
  attr_reader :bark #getter
  attr_writer :bark #setter
end

puts "7 #{(Dog3.instance_methods - Object.instance_methods).inspect}"


class Gaits
  attr_accessor :walk , :trot , :canter
end

puts "8 #{(Gaits.instance_methods.sort - Object.instance_methods ).inspect }"

#class variable = static variable in Java
class Repeat
  @@total = 0
  def initialize( string , times )
    @string = string
    @times = times
  end
  def repeat
    @@total += @times
    return @string * @times
  end
  def total
    "Total times , so far: " + @@total.to_s
  end
end

data  = Repeat.new( "a " , 8 )
data2 = Repeat.new( "b " , 5 )
data3 = Repeat.new( "c " , 2 )

puts "9  #{data.repeat }"
puts "10 #{data.total  }"
puts "11 #{data2.repeat}"
puts "12 #{data2.total }"
puts "13 #{data3.repeat}"
puts "14 #{data3.total }"

#class method = static method in Java

#inheritance is accomplished with < operator
class Name
  attr_accessor :given_name , :family_name
end

class Address < Name
  attr_accessor :street , :city , :state , :country
end

a = Address.new
puts "15 #{a.respond_to?( :given_name )}"
puts "16 #{(Address.instance_methods.sort - Object.instance_methods ).inspect }"


#modules
module Dice

  #virtual roll of a pair of dice
  def roll
    r_1 = rand(6)
    r_2 = rand(6)
    r1 = r_1 > 0 ? r_1 : 1
    r2 = r_2 > 0 ? r_2 : 6
    total = r1 + r2
    printf( "17 You rolled %d and %d (%d).\n" , r1 , r2 , total )
    total
  end
end

class Game
  include Dice
end

g = Game.new
g.roll

#static methods in modules
module Binary
  def Binary.to_bin( num )
    sprintf( "%08b" , num )
  end  
end

puts "18 #{Binary.to_bin( 123 )}"


#public , private , protected
class Names
  #public by default
  def initialize( a )
  end
  
  private
  def this_is_private
  end
  
  protected
  def this_is_protected
  end
end

1 Hello, world!
2 [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
3 Jimbo
4 ["bark", "bark="]
5 ["bark"]
6 woof!
7 ["bark", "bark="]
8 ["canter", "canter=", "trot", "trot=", "walk", "walk="]
9  a a a a a a a a 
10 Total times , so far: 8
11 b b b b b 
12 Total times , so far: 13
13 c c 
14 Total times , so far: 15
15 true
16 ["city", "city=", "country", "country=", "family_name", "family_name=", "given_name", "given_name=", "state", "state=", "street", "street="]
17 You rolled 3 and 1 (4).
18 01111011