Datastructures

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

Doubly Linked Lists

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

SplDoublyLinkedList
- SplStack
- SplQueue

Heaps

Heaps are tree-like structures that follow the heap-property: each node is greater than or equal to its children, when compared using the implemented compare method which is global to the heap.

SplHeap
- SplMaxHeap
- SplMinHeap
SplPriorityQueue