an example of Ruby Enumerable

gistfile1.rb

class Directory
  include Enumerable
  
  def initialize(dirname)
    @dirname = dirname
    @files = Dir.open(dirname) {|dir|
      dir.reject {|name| name == "." || name == ".." }
    }
  end
  
  def each(&block)
    if block_given?
      @files.each do |name|
        path = File.join(@dirname, name)
        if File.directory?(path)
          Directory.new(path).each(&block)
        else
          yield path
        end
      end
    else
      Enumerator.new(self, :each)
    end
  end
end