Nicolas Reynis

Its a nice concept but the proposed implementation will make defining visibility very complicated. Right now there are 3 visibility options, and its easy to understand what you can and cannot do when working with inheritance. Trying to understand the visibility hierarchy with this new RFC will take some time. https://wiki.php.net/rfc/asymmetric-visibility-v2#inheritance

This really makes the language complex.
The part with the interactions with the readonly keyword is really hard to make sense of.

I understand the subtle differences, don't get me wrong, it's just that I cannot understand them by just looking at the property definitions quickly. Imagine having to quickly make sense of a class with a dozen of properties like that. It's just nightmarish. I wouldn't accept a merge request that messy in my codebase.

I feel like if you need that much fine-grain control this is when having explicit getters/setters make sense.

Add property hooks on top of that and you have an explosion of complexity where you don't want: your domain logic is complex enough on it's own, you don't want to have properties become a maze.

It certainly is a fancy feature, but it takes too much a toll on the cognitive load.

Right now visibility is straight-forward. In a glance I can map in my head the possible operations on a property when I see its visibility. Adding this to the language will mean there will be moments that I'll have to stop and work out exactly what it means I can do with a property.

Also, property hooks already solve these use cases: defining a virtual property hook with only a getter will prevent you from setting the property, and vice versa.