Method LSet

structure/list.go:331–355

LSet sets the value of an element in a list associated with a key based on the index. If the index is out of range, an error is returned. If the list is empty, an error is returned.

(key string, index int, value interface{}, ttl int64)

// If the index is out of range, an error is returned.
// If the list is empty, an error is returned.
func (l *ListStructure) LSet(key string, index int, value interface{}, ttl int64) error {
	// Get the list
	lst, _, err := l.getListFromDB(key, false)
	if err != nil {
		return err
	}
	var expirationTime time.Duration
	// Check if the index is out of range
	if index < 0 || index >= lst.Length {
		return ErrIndexOutOfRange
	}

	nowNode := lst.Head

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

	nowNode.Value = value
	if ttl > 0 {
		expirationTime = time.Duration(ttl) * time.Second
	}
	// Store in the database
	return l.setListToDB(key, lst, expirationTime)
}

// LTrim retains a range of elements in a list associated with a key.
// The range is inclusive, including both the start and stop indices.