if length <= nameSize || !isASCII(name) {
		return "", "", false
	} else if length > prefixSize+1 {
		length = prefixSize + 1
	} else if name[length-1] == '/' {
		length--
	}

	i := strings.LastIndex(name[:length], "/")
	nlen := len(name) - i - 1 // nlen is length of suffix
	plen := i                 // plen is length of prefix
	if i <= 0 || nlen > nameSize || nlen == 0 || plen > prefixSize {
		return "", "", false

}

func indexBytePortable(s []byte, c byte) int {
	for i, b := range s {
		if b == c {
			return i
		}
	}
	return -1
}

// LastIndex returns the index of the last instance of sep in s, or -1 if sep is not present in s.
func LastIndex(s, sep []byte) int {
	n := len(sep)
	switch {
	case n == 0:
		return len(s)
	case n == 1:
		return bytealg.LastIndexByte(s, sep[0])
	case n == len(s):

pkg bytes, func IndexByte([]uint8, uint8) int
pkg bytes, func IndexFunc([]uint8, func(int32) bool) int
pkg bytes, func IndexRune([]uint8, int32) int
pkg bytes, func Join([][]uint8, []uint8) []uint8
pkg bytes, func LastIndex([]uint8, []uint8) int
pkg bytes, func LastIndexAny([]uint8, string) int
pkg bytes, func LastIndexFunc([]uint8, func(int32) bool) int
pkg bytes, func Map(func(int32) int32, []uint8) []uint8