As software engineers, we know that we need to use the proper data structure to handle each task. Depending on the data structure we use to process a collection, we might not achieve our goals at all.
On PHP, we don't have that concern, because we have one way of dealing with all of them: Arrays. We can reduce greatly the memory usage, and related to that, improve the performance of the application.
This is the extension source: https://github.com/php-ds/ext-ds
To install you just need to run:
pecl install ds
For some benchmarking about this package, you can check here: https://medium.com/@rtheunissen/efficient-data-structures-for-php-7-9dda7af674cd