func convertToString()

in convert.go [57:152]
73 lines of code
24 McCabe index (conditional complexity)

func convertToString(val reflect.Value, options reflect.StructTag) (string, error) {
	if ok, ret, err := convertMarshal(val); ok {
		return ret, err
	}

	tp := val.Type()

	// Support for time.Duration
	if tp == reflect.TypeOf((*time.Duration)(nil)).Elem() {
		stringer := val.Interface().(fmt.Stringer)
		return stringer.String(), nil
	}

	switch tp.Kind() {
	case reflect.String:
		return val.String(), nil
	case reflect.Bool:
		if val.Bool() {
			return "true", nil
		}

		return "false", nil
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		base, err := getBase(options, 10)

		if err != nil {
			return "", err
		}

		return strconv.FormatInt(val.Int(), base), nil
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		base, err := getBase(options, 10)

		if err != nil {
			return "", err
		}

		return strconv.FormatUint(val.Uint(), base), nil
	case reflect.Float32, reflect.Float64:
		return strconv.FormatFloat(val.Float(), 'g', -1, tp.Bits()), nil
	case reflect.Slice:
		if val.Len() == 0 {
			return "", nil
		}

		ret := "["

		for i := 0; i < val.Len(); i++ {
			if i != 0 {
				ret += ", "
			}

			item, err := convertToString(val.Index(i), options)

			if err != nil {
				return "", err
			}

			ret += item
		}

		return ret + "]", nil
	case reflect.Map:
		ret := "{"

		for i, key := range val.MapKeys() {
			if i != 0 {
				ret += ", "
			}

			keyitem, err := convertToString(key, options)

			if err != nil {
				return "", err
			}

			item, err := convertToString(val.MapIndex(key), options)

			if err != nil {
				return "", err
			}

			ret += keyitem + ":" + item
		}

		return ret + "}", nil
	case reflect.Ptr:
		return convertToString(reflect.Indirect(val), options)
	case reflect.Interface:
		if !val.IsNil() {
			return convertToString(val.Elem(), options)
		}
	}

	return "", nil
}