if start >= 0 {
			yield(s[start:len(s):len(s)])
		}
	}
}

// FieldsFuncSeq returns an iterator over subslices of s split around runs of
// Unicode code points satisfying f(c).
// The iterator yields the same subslices that would be returned by [FieldsFunc](s),
// but without constructing a new slice containing the subslices.
func FieldsFuncSeq(s []byte, f func(rune) bool) iter.Seq[[]byte] {
	return func(yield func([]byte) bool) {