op.go
func Index(index int) OpFunc {
	return func(in []byte) ([]byte, error) {
		return scanner.FindIndex(in, 0, index)
	}
}
func Index(index int) OpFunc {
	return func(in []byte) ([]byte, error) {
		return scanner.FindIndex(in, 0, index)
	}
}
// Index extracts a specific element from the array provided