Method LIndex

structure/list.go:412–434

LIndex returns the value of an element in a list associated with a key based on the index. If the key does not exist, an error is returned. If the list is empty, an error is returned. Negative indices can be used, where -1 represents the last element of the list, -2 represents the second last elemen

(key string, index int)

// Negative indices can be used, where -1 represents the last element of the list,
// -2 represents the second last element, and so on.
func (l *ListStructure) LIndex(key string, index int) (interface{}, error) {
	// Get the list
	lst, _, err := l.getListFromDB(key, false)
	if err != nil {
		return nil, err
	}

	// Return error if the list is empty
	if lst.Length == 0 {
		return nil, ErrListEmpty
	}

	// Calculate the correct index
	index = (index%lst.Length + lst.Length) % lst.Length

	nowNode := lst.Head

	for i := 0; i < index; i++ {
		nowNode = nowNode.Next
	}

	return nowNode.Value, nil
}

// Keys returns all the keys of the list structure.
func (l *ListStructure) Keys(regx string) ([]string, error) {