ability to create classes and modules in a namespace

namespace.rb

module Namespace
  class Manager
    def initialize(namespace)
      @managed = namespace
    end
    
    def create_module(name, &block)
      mod = Module.new(&block)
      @managed.const_set(name, mod)
      mod
    end

    def create_class(name, parent: Object, &block)
      klass = Class.new(parent, &block)
      @managed.const_set(name, klass)
      klass
    end
  end
  
  def namespace(string, &block)
    namespace = string.split('::').inject(Object) do |base, mod|
      base.const_get(mod)
    end
    Manager.new(namespace).instance_eval(&block)
  end
end

extend Namespace

class Thing
  class Form
  end
end

namespace 'Thing::Form' do
  create_module(:Mod) do
    def hello
      'hi'
    end
  end

  create_class(:Klass) do
    def hello
      'it works'
    end
  end
end

puts Thing::Form::Mod.instance_method(:hello).bind(self).call
puts Thing::Form::Klass.new.hello