# File lib/rbot/core/utils/extends.rb, line 297
  def Regexp.new_list(reg, pfx = "")
    if pfx.kind_of?(String) and pfx.empty?
      return %r(#{reg}(?:,?(?:\s+and)?\s+#{reg})*)
    else
      return %r(#{reg}(?:,?(?:\s+and)?(?:\s+#{pfx})?\s+#{reg})*)
    end
  end