code: func (ran *Range) String() string {
  	lowStrs := make([]string, 0, len(ran.LowVal))
  	for _, d := range ran.LowVal {
  		lowStrs = append(lowStrs, formatDatum(d, true))
  	}
  	highStrs := make([]string, 0, len(ran.LowVal))
  	for _, d := range ran.HighVal {
  		highStrs = append(highStrs, formatDatum(d, false))
  	}
  	l, r := "[", "]"
  	if ran.LowExclude {
  		l = "("
  	}
  	if ran.HighExclude {
  		r = ")"
  	}
  	return l + strings.Join(lowStrs, " ") + "," + strings.Join(highStrs, " ") + r
  }
docs: // String implements the Stringer interface.