mod_inheritance.rb

module Concern
  def modname
    self.name
  end
end

module Validation
  extend Concern

  module EventValidation; end
end

def show_modname(mod)
  mod.modname rescue "modname undefined for #{mod}"
end 

puts show_modname(Validation) #=> "Validation"
puts show_modname(Validation::EventValidation) #=> "modname undefined for EventValidation"