func buildDocumentPath()

in dax/internal/client/projection.go [60:110]
41 lines of code
10 McCabe index (conditional complexity)

func buildDocumentPath(path string, expressionAttributeNames map[string]string) (documentPath, error) {
	var substitutes map[string]string
	if expressionAttributeNames != nil {
		substitutes = expressionAttributeNames
	}

	res := strings.Split(path, ".")
	var elements []documentPathElement

	for _, re := range res {
		idx := strings.Index(re, "[")
		if idx == -1 {
			elements = append(elements, documentPathElementFromName(getOrDefault(substitutes, re, re)))
			continue
		}

		if idx == 0 {
			return documentPath{}, errors.New("invalid path: " + path)
		}

		pre := re[0:idx]
		elements = append(elements, documentPathElementFromName(getOrDefault(substitutes, pre, pre)))

		for idx != -1 {
			re = re[idx+1:]
			idx = strings.Index(re, "]")

			if idx == -1 {
				return documentPath{}, errors.New("invalid path: " + path)
			}

			lidx, err := strconv.Atoi(re[:idx])
			if err != nil {
				return documentPath{}, err
			}
			elements = append(elements, documentPathElementFromIndex(lidx))

			re = re[idx+1:]
			idx = strings.Index(re, "[")
			if idx > 0 {
				return documentPath{}, errors.New("invalid path: " + path)
			}
		}

		if len(elements) == 0 {
			return documentPath{}, errors.New("invalid path: " + path)
		}
	}

	return documentPath{elements: elements}, nil
}