Function Parse

dpkgversion/dpkgversion.go:127–176

Parse returns a Version struct filled with the epoch, version and revision specified in input. It verifies the version string as a whole, just like dpkg(1), and even returns roughly the same error messages.

(input string)

// specified in input. It verifies the version string as a whole, just like
// dpkg(1), and even returns roughly the same error messages.
func Parse(input string) (Version, error) {
	result := Version{}
	trimmed := strings.TrimSpace(input)
	if trimmed == "" {
		return result, fmt.Errorf("version string is empty")
	}

	if strings.IndexFunc(trimmed, unicode.IsSpace) != -1 {
		return result, fmt.Errorf("version string has embedded spaces")
	}

	colon := strings.Index(trimmed, ":")
	if colon != -1 {
		epoch, err := strconv.ParseInt(trimmed[:colon], 10, 64)
		if err != nil {
			return result, fmt.Errorf("epoch: %v", err)
		}
		if epoch < 0 {
			return result, fmt.Errorf("epoch in version is negative")
		}
		result.Epoch = uint(epoch)
	}

	result.Version = trimmed[colon+1:]
	if len(result.Version) == 0 {
		return result, fmt.Errorf("nothing after colon in version number")
	}
	if hyphen := strings.LastIndex(result.Version, "-"); hyphen != -1 {
		result.Revision = result.Version[hyphen+1:]
		result.Version = result.Version[:hyphen]
	}

	if len(result.Version) > 0 && !unicode.IsDigit(rune(result.Version[0])) {
		return result, fmt.Errorf("version number does not start with digit")
	}

	if strings.IndexFunc(result.Version, func(c rune) bool {
		return !cisdigit(c) && !cisalpha(c) && c != '.' && c != '-' && c != '+' && c != '~' && c != ':'
	}) != -1 {
		return result, fmt.Errorf("invalid character in version number")
	}

	if strings.IndexFunc(result.Revision, func(c rune) bool {
		return !cisdigit(c) && !cisalpha(c) && c != '.' && c != '+' && c != '~'
	}) != -1 {
		return result, fmt.Errorf("invalid character in revision number")
	}

	return result, nil
}

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