ListQueue<E> class

List based Queue.

Keeps a cyclic buffer of elements, and grows to a larger buffer when it fills up. This guarantees constant time peek and remove operations, and amortized constant time add operations.

The structure is efficient for any queue or stack usage.

Example:

final queue = ListQueue<int>();

To add objects to a queue, use add, addAll, addFirst oraddLast.

queue.add(5);
queue.addFirst(0);
queue.addLast(10);
queue.addAll([1, 2, 3]);
print(queue); // {0, 5, 10, 1, 2, 3}

To check if the queue is empty, use isEmpty or isNotEmpty. To find the number of queue entries, use length.

final isEmpty = queue.isEmpty; // false
final queueSize = queue.length; // 6

To get first or last item from queue, use first or last.

final first = queue.first; // 0
final last = queue.last; // 3

To get item value using index, use elementAt.

final itemAt = queue.elementAt(2); // 10

To convert queue to list, call toList.

final numbers = queue.toList();
print(numbers); // [0, 5, 10, 1, 2, 3]

To remove item from queue, call remove, removeFirst or removeLast.

queue.remove(10);
queue.removeFirst();
queue.removeLast();
print(queue); // {5, 1, 2}

To remove multiple elements at the same time, use removeWhere.

queue.removeWhere((element) => element == 1);
print(queue); // {5, 2}

To remove all elements in this queue that do not meet a condition, use retainWhere.

queue.retainWhere((element) => element < 4);
print(queue); // {2}

To remove all items and empty the set, use clear.

queue.clear();
print(queue.isEmpty); // true
print(queue); // {}