A simple polymorphic functional double-ended queue. Use this if you need a queue-like
data structure that provides enqueue and dequeue accessors on both ends. For
strictly first-in, first-out access, see
Amortized running times assume that enqueue/dequeue are used sequentially, threading the changing deque through the calls.
Checks whether the provided element is there, using polymorphic compare if
is not provided
fold t ~init ~f returns
f (... f (f (f init e1) e2) e3 ...) en, where
are the elements of
true if and only if there exists an element for which the provided
function evaluates to
true. This is a short-circuiting operation.
true if and only if the provided function evaluates to
true for all
elements. This is a short-circuiting operation.
Returns the number of elements for which the provided function evaluates to true.
Returns as an
option the first element for which
f evaluates to true.
Returns the first evaluation of
f that returns
Some, and returns
None if there
is no such element.
Returns a minimum (resp maximum) element from the collection using the provided
cmp function, or
None if the collection is empty. In case of a tie, the first
element encountered while traversing the collection is returned. The implementation
fold so it has the same complexity as
The empty deque.
A one-element deque.
of_list returns a deque with elements in the same front-to-back order as the
peek t side produces
Some of the element at the
Complexity: worst-case O(1).