SPL provies a set of standard datastructures. They are grouped here by their underlying implementation which usually defines their general field of application.

A Doubly Linked List (DLL) is a list of nodes linked in both directions to each others. Iterator's operations, or access to both ends have a cost of O(1) when the underlying structure is a DLL. It hence provides a decent implementation of stacks and queues. SplDoublyLinkedList SplStack SplQueue

&reference.spl.spldoublylinkedlist; &reference.spl.splstack; &reference.spl.splqueue;