Some ruby samples playing with classes

class_samples.rb

# Playing with classes and structs

MyClass = Class.new

p MyClass.class

# => Class

my_instance = MyClass.new

p my_instance

# => #<MyClass:0x10c67c840>

p my_instance.class

# => MyClass

# Structs

Car = Struct.new(:brand, :model)

p Car.class

# => Class

car1 = Car.new("Peugeot", "206")

p car1.brand
# => "Peugeot"

car2 = Car.new(Struct.new("Brand", :name).new("Peugeot"), "206") 

p car2.brand 
# => #<struct Struct::Brand name="Peugeot">

p car2.brand.name
# => "Peugeot"

require 'yaml'
p car2.to_yaml

=begin
  
  --- !ruby/struct:Car 
  brand: !ruby/struct:Brand 
    name: Peugeot
  model: "206"

=end

# Oh noes ! I have no references to the Brand class to create new instances :(

if car2.brand.class.respond_to? :name    # ensure we got a brand-similar class by duck typing

  my_lost_class = car2.brand.class

  another_brand = my_lost_class.new("Porsche")

  p another_brand.name

  # => "Porsche"

  p another_brand.class

  # => Struct::Brand
end