func scanBoolean()

in metric/parse.go [553:606]

• 40 lines of code
• 24 McCabe index (conditional complexity)

func scanBoolean(buf []byte, i int) (int, []byte, error) {
	start := i

	if i < len(buf) && (buf[i] != 't' && buf[i] != 'f' && buf[i] != 'T' && buf[i] != 'F') {
		return i, buf[start:i], makeError("invalid value", buf, i)
	}

	i++
	for {
		if i >= len(buf) {
			break
		}

		if buf[i] == ',' || buf[i] == ' ' {
			break
		}
		i++
	}

	// Single char bool (t, T, f, F) is ok
	if i-start == 1 {
		return i, buf[start:i], nil
	}

	// length must be 4 for true or TRUE
	if (buf[start] == 't' || buf[start] == 'T') && i-start != 4 {
		return i, buf[start:i], makeError("invalid boolean", buf, i)
	}

	// length must be 5 for false or FALSE
	if (buf[start] == 'f' || buf[start] == 'F') && i-start != 5 {
		return i, buf[start:i], makeError("invalid boolean", buf, i)
	}

	// Otherwise
	valid := false
	switch buf[start] {
	case 't':
		valid = bytes.Equal(buf[start:i], []byte("true"))
	case 'f':
		valid = bytes.Equal(buf[start:i], []byte("false"))
	case 'T':
		valid = bytes.Equal(buf[start:i], []byte("TRUE")) || bytes.Equal(buf[start:i], []byte("True"))
	case 'F':
		valid = bytes.Equal(buf[start:i], []byte("FALSE")) || bytes.Equal(buf[start:i], []byte("False"))
	}

	if !valid {
		return i, buf[start:i], makeError("invalid boolean", buf, i)
	}

	return i, buf[start:i], nil

}