.. index:: single: deque .. _deque/0:

.. rst-class:: right

object

deque

Double-ended queue (deque) implementation using difference lists to provide O(1) operations at both ends.

| Availability: | logtalk_load(deques(loader))

| Author: Paulo Moura | Version: 1:0:0 | Date: 2026-02-09

| Compilation flags: | static, context_switching_calls

| Implements: | public :ref:`deque_protocol <deque_protocol/0>` | Extends: | public :ref:`compound <compound/0>` | Uses: | :ref:`list <list/0>`

| Remarks: | (none)

| Inherited public predicates: |  :ref:`comparingp/0::(<)/2`  :ref:`comparingp/0::(=:=)/2`  :ref:`comparingp/0::(=<)/2`  :ref:`comparingp/0::(=\=)/2`  :ref:`comparingp/0::(>)/2`  :ref:`comparingp/0::(>=)/2`  :ref:`deque_protocol/0::as_deque/2`  :ref:`deque_protocol/0::as_list/2`  :ref:`termp/0::check/1`  :ref:`termp/0::depth/2`  :ref:`deque_protocol/0::empty/1`  :ref:`termp/0::ground/1`  :ref:`deque_protocol/0::length/2`  :ref:`deque_protocol/0::map/2`  :ref:`deque_protocol/0::map/3`  :ref:`termp/0::new/1`  :ref:`termp/0::numbervars/1`  :ref:`termp/0::numbervars/3`  :ref:`termp/0::occurs/2`  :ref:`deque_protocol/0::peek_back/2`  :ref:`deque_protocol/0::peek_front/2`  :ref:`deque_protocol/0::pop_back/3`  :ref:`deque_protocol/0::pop_front/3`  :ref:`deque_protocol/0::push_back/3`  :ref:`deque_protocol/0::push_front/3`  :ref:`termp/0::singletons/2`  :ref:`termp/0::subsumes/2`  :ref:`termp/0::subterm/2`  :ref:`termp/0::valid/1`  :ref:`termp/0::variables/2`  :ref:`termp/0::variant/2`  :ref:`termp/0::varnumbers/2`  :ref:`termp/0::varnumbers/3`  

.. contents:: :local: :backlinks: top

Public predicates

(no local declarations; see entity ancestors if any)

Protected predicates

(no local declarations; see entity ancestors if any)

Private predicates

(no local declarations; see entity ancestors if any)

Operators

(none)