class ActiveSupport::NumberHelper::NumberToRoundedConverter

def convert
  helper = RoundingHelper.new(options)
  rounded_number = helper.round(number)
  if precision = options[:precision]
    if options[:significant] && precision > 0
      digits = helper.digit_count(rounded_number)
      precision -= digits
      precision = 0 if precision < 0 # don't let it be negative
    end
    formatted_string =
      if rounded_number.finite?
        s = rounded_number.to_s("F")
        a, b = s.split(".", 2)
        if precision != 0
          b << "0" * precision
          a << "."
          a << b[0, precision]
        end
        a
      else
        # Infinity/NaN
        "%f" % rounded_number
      end
  else
    formatted_string = rounded_number
  end
  delimited_number = NumberToDelimitedConverter.convert(formatted_string, options)
  format_number(delimited_number)
end

def format_number(number)
  if strip_insignificant_zeros
    escaped_separator = Regexp.escape(options[:separator])
    number.sub(/(#{escaped_separator})(\d*[1-9])?0+\z/, '\1\2').sub(/#{escaped_separator}\z/, "")
  else
    number
  end
end

def strip_insignificant_zeros
  options[:strip_insignificant_zeros]
end