gistfile1.rb

module Ahoy
  def self.included(base)
    base.public_instance_methods.select {|m| m.to_s =~ /ar/ }.each do |method_name|
      base.class_eval("alias #{method_name.gsub("ar", "arrr")} #{method_name}")
    end
  end
end

gistfile2.rb

class String
  include Ahoy
end

"foo".starrrt_with? "f"
# => true