An example of using builder Builder pattern in Ruby design pattern programming _ruby Special Topics

Let's review the basic concepts of design patterns:
definition
the construction of a complex object is separated from its representation, allowing the same build process to create different representations.
Builders Hide how the product is assembled, so if you need to change the internal representation of a product, you just need to redefine a builder.
Practical Range
1. When creating complex objects, the algorithms should be independent of the components of the object and the way they are assembled.
2. When the construction process must allow the constructed object to have a different representation.
role
in such a design pattern, there are several roles:
1.builder: Specifies an abstract interface for each part that creates a product object.
2.ConcreteBuilder: Implements the builder interface to construct and assemble the parts of the product, define and identify the representations it creates, and provide an interface to retrieve the product.
3.Director: Constructs an object that uses the builder interface.
4.Product: Represents a constructed complex object. ConcreteBuilder creates an internal representation of the product and defines its assembly process, containing the classes that define the components, including the interfaces that assemble the parts into the final product.
Let's take a look at an example:
Requirements:

Draw a villain, have a head, have a body, both hands two feet can.

Initial code:

#-*-encoding: utf-8-*-

#Villain one
puts 'This is the first villain'
puts 'Little Man One: Head'
puts 'Little man one: thin body'
puts 'One villain: both hands'
puts 'Little Man One: Feet'

#Villain two
puts 'This is the second villain'
puts 'Little Man 2: Head'
puts 'Little Man 2: Fat Body'
puts 'Little man two: hands'
puts 'Little man two: feet'
'

Problem: Code duplication, and error prone, lack of arms and legs and so on.

Improved code:

#-*-Encoding:utf-8-*-

#
class Persionbuilder
  def head
    puts ' end
  def body
    puts
  ' End
  def arm
    puts "end
  def leg
    puts" end

#Villain one

class Persionthinbuilder < Persionbuilder
  def
    head puts ' tau '
  end
  def
    body puts ' thin bodies '
  def arm
    puts ' hands '
  end
  def leg
    puts ' feet ' end
#Villain two

class Persionfatbuilder < Persionbuilder
  def
    head puts ' heads '
  end
  def
    bodies puts ' fat body '
  def arm
    puts ' hands '
  end
  def leg
    puts ' feet ' end

#Conductor class class Persiondirect
  def initialize (persion)
    @persion = persion
  end
  
  def create_persion
    @ Persion.head
    @persion. Body
    @persion, arm
    @persion. Leg
  End
puts ' This is the first villain '
P1 = persionthinbuilder.new
pd1 = Persiondirect.new (p1)
pd1.create_persion puts

' This is the second villain '
P2 = Persionthinbuilder.new
pd2 = persiondirect.new (p2)
pd2.create_persion