Autoloader loads ruby files lazily

autoloader.rb

module AutoLoader
  def self.included(mod)
    caller_path, = caller(1..1).first.partition(':')
    pattern = "#{File.dirname(caller_path)}/#{File.basename(caller_path, '.rb')}/*.rb"
    Dir.glob(pattern).each do |path|
      class_name = ::Utils.classify(File.basename(path, '.rb')).to_sym
      mod.autoload class_name, path
    end
  end
end

example.rb

# foo.rb
module Foo
  include Autoloader
end

# foo/bar.rb
module Foo
  class Bar
  end
end


# foo/buz.rb
module Foo
  class Buz
  end
end

# main.rb
require 'foo'
Foo::Bar.new # autoload foo/bar.rb
Foo::Buz.new # autoload foo/buz.rb