code: func ToFloat(value interface{}) float64 {
  	if result := ToString(value); result == "" {
  		return 0
  	} else if i, err := strconv.ParseFloat(result, 64); err == nil {
  		return i
  	} else {
  		panic("failed to parse float: " + result)
  	}
  }
docs: // ToFloat get float from value, if passed value is empty string, result will be 0