Understanding Enumerator class of Ruby.

enum_behavior.rb

class Response
  def response_body=(enum)
    enum.each {|e| puts "res: #{e}" }
  end
end

def gen_stream
  Enumerator.new do |yielder|
    10.times do |num|
      puts "stream: #{num}"
      yielder << num
    end
  end
end

Response.new.response_body = gen_stream

## Output

# stream: 0
# res: 0
# stream: 1
# res: 1
# stream: 2
# res: 2
# stream: 3
# res: 3
# stream: 4
# res: 4
# stream: 5
# res: 5
# stream: 6
# res: 6
# stream: 7
# res: 7
# stream: 8
# res: 8
# stream: 9
# res: 9