Function ParsePath

path_compiler.go:17–96

ParsePath converts a JSONPath-style path into the path components accepted by Get, Set, Delete, ArrayEach, and EachKey. SYS-REQ-114

(jsonPath string)

// by Get, Set, Delete, ArrayEach, and EachKey.
// SYS-REQ-114
func ParsePath(jsonPath string) ([]string, error) {
	if jsonPath == "" {
		return nil, errEmptyPath
	}

	switch {
	case jsonPath == "$":
		return []string{}, nil
	case strings.HasPrefix(jsonPath, "$."):
		jsonPath = jsonPath[2:]
	case strings.HasPrefix(jsonPath, "$["):
		jsonPath = jsonPath[1:]
	case jsonPath[0] == '$':
		return nil, errMalformedPath
	}

	if jsonPath == "" {
		return nil, errMalformedPath
	}

	// A path component is either a dot-delimited key or bracket notation.
	// Counting both separators gives an exact capacity for ordinary paths and
	// a safe upper bound for quoted keys containing dots or brackets.
	parts := make([]string, 0, 1+strings.Count(jsonPath, ".")+strings.Count(jsonPath, "["))

	for pos := 0; pos < len(jsonPath); {
		switch jsonPath[pos] {
		case '.':
			return nil, errMalformedPath
		case '"':
			key, next, err := parseQuotedPathKey(jsonPath, pos)
			if err != nil {
				return nil, err
			}
			parts = append(parts, key)
			pos = next
		case '[':
			// A root array path or a bracket immediately following a dot has
			// no key component before its index.
		default:
			start := pos
			for pos < len(jsonPath) && jsonPath[pos] != '.' && jsonPath[pos] != '[' {
				if jsonPath[pos] == ']' || jsonPath[pos] == '"' {
					return nil, errMalformedPath
				}
				pos++
			}
			if start == pos {
				return nil, errMalformedPath
			}
			parts = append(parts, jsonPath[start:pos])
		}

		for pos < len(jsonPath) && jsonPath[pos] == '[' {
			component, next, err := parseBracketPathComponent(jsonPath, pos)
			if err != nil {
				return nil, err
			}