Queue containing elements of type 'a

Push element at the front of the queue.

Push element at the end of the queue.

Get and remove the first element.

Same as take_front, but fails on empty queues.

• raises Empty

  if the queue is empty.

take_front_l n q takes at most n elements from the front of q, and returns them wrapped in a list.

• raises Invalid_argument

  if n<0.

Take last element.

Same as take_back, but fails on empty queues.

• raises Empty

  if the queue is empty.

take_back_l n q removes and returns the last n elements of q. The elements are in the order of the queue, that is, the head of the returned list is the first element to appear via take_front. take_back_l 2 (of_list [1;2;3;4]) = of_list [1;2], [3;4].

• raises Invalid_argument

  if n<0.

First element of the queue.

Last element of the queue.

Same as first but

• raises Empty

  if the queue is empty.

Return the i-th element of the queue in logarithmic time.

Unsafe version of nth.

• raises Not_found

  if the index is wrong.

Queue deprived of its first element. Does nothing on empty queues.

Queue deprived of its last element. Does nothing on empty queues.

Append two queues. Elements from the second one come after elements of the first one. Linear in the size of the second queue.

Reverse the queue, O(n) complexity.

• since 0.10

Map values.

Synonym to map.

Number of elements in the queue (constant time).

a -- b is the integer range from a to b, both included.

• since 0.10

a -- b is the integer range from a to b, where b is excluded.

• since 0.17

• since 0.13