In this recent article over on Medium.com Rudi Theunissen looks at more efficient data structures for PHP 7 and the introduction of a library that wants to help replace some of the current functionality and dependencies on things like arrays.

PHP has one data structure to rule them all. The array is a complex, flexible, master-of-none, hybrid data structure, combining the behaviour of a list and a linked map. But we use it for everything, because PHP is pragmatic.

[...] The recent release of PHP 7 caused a lot of excitement in the PHP community. We couldn't wait to start using the new features and get a taste of the ~2x performance boost. One of the reasons why it runs that much faster is because the array was redesigned. But it’s still the same structure, “optimised for everything; optimised for nothing” with room for improvement.

He starts with a brief mention of some of the current topics around data structures - the SPL functionality, why fixing them would be difficult and, finally, introducing the library that seeks to supersede them. The remainder of the post goes through the pieces of functionality the library offers and explains how each works including videos and graphs of the performance results:

• Collection
• Sequence
• Vector
• Deque
• Stack
• Queue and PriorityQueue
• Hashable
• Map
• Set

He also answers some of the most common questions he's gotten about the library including the level of testing, documentation for the project and why he structured certain elements and features how he did.