Hi, I'm Derick. And this is PHP internals news, a weekly podcast dedicated to demystifying the development of the PHP language. This is Episode 53. Today I'm talking with Nikita Popov about a few RFCs that he's made in the last few weeks. Let's start with the constructor property promotion RFC.

Hello Nikita, would you please introduce yourself? Hi, Derick. I am Nikita and I am doing PHP internals work at JetBrains and the constructor promotion, constructor property promotion RFC is the result of some discussion about how we can improve object ergonomics in PHP.

Object economics. It's something that I spoke with Larry Garfield about two episodes ago, where we discuss Larry's proposal or overview of what can be improved with object ergonomics in PHP. And I think we mentioned that you just landed this RFC that we're now talking about. What is the part of the object ergonomics proposal that this RFC is trying to solve?

I mean, the basic problem we have right now is that it's a bit more inconvenient than it really should be to use simple value objects in PHP. And there is two sides to that problem. One is on the side of writing the class declaration, and the other part is on the side of instantiating the object. This RFC tries to make the class declaration simpler, and shorter, and less redundant.

At the moment, how would a typical class instantiation constructor look like?

Right now, if we take simple examples from the RFC, we have a class Point, which has three properties, x, y, and Zed. And each of those has a float type. And that's really all the class is. Ideally, this is all we would have to write. But of course, to make this object actually usable, we also have to provide a constructor. And the constructor is going to repeat that. Yes, we want to accept three floating point numbers x, y, and Zed as parameters. And then in the body, we have to again repeat that, okay, each of those parameters needs to be assigned to a property. So we have to write this x equals x, this y equals y, this z equals z. I think for the Point class this is still not a particularly large burden. Because we have like only three properties. The names are nice and short. The types are really short. We don't have to write a lot of code, but if you have larger classes with more properties, with more constructor arguments, with larger and more descriptive names, and also larger and more descriptive type names, then this makes up for quite a bit of boilerplate code.

Because you're pretty much having the properties' names in there three times.

Four times even. One is the property name and the declaration, one in the parameter, and then you have to the assignment has to repeat it twice.

You're repeating the property names four times, and the types twice.

Right.