func addrToByteRange()

in internal/codewalk/codewalk.go [295:383]

• 83 lines of code
• 23 McCabe index (conditional complexity)

func addrToByteRange(addr string, start int, data []byte) (lo, hi int, err error) {
	var (
		dir        byte
		prevc      byte
		charOffset bool
	)
	lo = start
	hi = start
	for addr != "" && err == nil {
		c := addr[0]
		switch c {
		default:
			err = errors.New("invalid address syntax near " + string(c))
		case ',':
			if len(addr) == 1 {
				hi = len(data)
			} else {
				_, hi, err = addrToByteRange(addr[1:], hi, data)
			}
			return

		case '+', '-':
			if prevc == '+' || prevc == '-' {
				lo, hi, err = addrNumber(data, lo, hi, prevc, 1, charOffset)
			}
			dir = c

		case '$':
			lo = len(data)
			hi = len(data)
			if len(addr) > 1 {
				dir = '+'
			}

		case '#':
			charOffset = true

		case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
			var i int
			for i = 1; i < len(addr); i++ {
				if addr[i] < '0' || addr[i] > '9' {
					break
				}
			}
			var n int
			n, err = strconv.Atoi(addr[0:i])
			if err != nil {
				break
			}
			lo, hi, err = addrNumber(data, lo, hi, dir, n, charOffset)
			dir = 0
			charOffset = false
			prevc = c
			addr = addr[i:]
			continue

		case '/':
			var i, j int
		Regexp:
			for i = 1; i < len(addr); i++ {
				switch addr[i] {
				case '\\':
					i++
				case '/':
					j = i + 1
					break Regexp
				}
			}
			if j == 0 {
				j = i
			}
			pattern := addr[1:i]
			lo, hi, err = addrRegexp(data, lo, hi, dir, pattern)
			prevc = c
			addr = addr[j:]
			continue
		}
		prevc = c
		addr = addr[1:]
	}

	if err == nil && dir != 0 {
		lo, hi, err = addrNumber(data, lo, hi, dir, 1, charOffset)
	}
	if err != nil {
		return 0, 0, err
	}
	return lo, hi, nil
}