people_factory.rb

class Person
  attr_reader :factory
  attr_reader :name

  def initialize(factory, name)
    @factory = factory
    @name = name
  end

  def coworkers
    @factory.list
  end

  def coworkers_count
    # the total size, minus yourself
    coworkers.size - 1
  end
end

class PersonFactory
  attr_reader :list

  def initialize
    @list = []
  end

  private def add(person)
    @list << person
    person
  end

  def create(*args)
    add Person.new(self, *args)
  end
end


icedragons_factory = PersonFactory.new
workmad3_factory = PersonFactory.new

jr = icedragons_factory.create 'IceDragonjr'
icedragons_factory.create 'SomeDude'
icedragons_factory.create 'Bacon'
icedragons_factory.create 'ExtraDude'

wjr = workmad3_factory.create 'Workmad3jr'
workmad3_factory.create 'aPancake'
workmad3_factory.create 'TheGreatBacon'


jr.coworkers_count #=> 3
wjr.coworkers_count #=> 2