Monkey-patch enumerator to call a progress object when iterating

output.txt

1
"increment"
2
"increment"
3
"increment"

with_progress.rb

class Progress

  def increment
    p 'increment'
  end

end

module Enumerable
  
  def with_progress(progress)
    Enumerator.new do |yielder|
      each do |e|
        yielder.yield e
        progress.increment
      end
    end
  end

end

progress = Progress.new
[1, 2, 3].with_progress(progress).each do |e|
  p e
end