In my last post, I went over some of the pros and cons of various proposals for making PHP objects more immutable-ish, and the contexts in which they would be useful. I also posted the link to the PHP Internals list, where it generated some interesting if meandering discussion (as is par for the course on Internals).
One of the requests was for sample code to demonstrate why I felt particular feature proposals were better than others. Fair enough! This post is in response to that request, and I think it will help illuminate the challenges better.
For this exercise, I chose to experiment with a junior version of the PSR-7 request object as a concrete example. The code below is not exactly PSR-7; it's a representative sample of portions of a naive, slightly reduced scope version of PSR-7 requests only, and using all PHP 8.0 features available. The goal is not a complete working object, but sufficient real-world representative examples of situations that an immutability plan would need to address.
Continue reading this post on PeakD.