Return blackhole object with maybe(something), but convert blackhole back to nil with a chain-closing method. Because sometimes we need to send values to outside code that understands the nil idiom, but not our "exotic" blackhole object.

unmaybe.rb

class BlackHole
  def method_missing(*args, &block)
    self
  end

  def unmaybe
    nil
  end

  # ...
end

def maybe(thing)
  thing.nil? ? BlackHole.new : thing
end

class Object
  def unmaybe
    self
  end
end

a_thing = "A string of sorts."

maybe(a_thing)[0..5].downcase.unmaybe #=> "a stri"

a_thing = nil

maybe(a_thing)[0..5].downcase.unmaybe #=> nil