PHP Internals News: Episode 95: PHP 8.1 Celebrations

Thursday, November 25th 2021, 09:23 GMT

In this episode of "PHP Internals News" we're looking back at all the RFCs that we discussed on this podcast for PHP 8.1. In their own words, the RFC authors explain what these features are, with your host interjecting his own comments on the state of affairs.

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Transcript

Derick Rethans 0:14: Hi, I'm Derick, and this is PHP internals news, a weekly podcast dedicated to demystifying the development of the PHP language.
Derick Rethans 0:23: This is episode 95. I've been absent on the podcast for the last few months due to other commitments. It takes approximately four hours to make each episode. And I can now unfortunately not really justify spending the time to work on it. I have yet to decide whether I will continue with it next year to bring you all the exciting development news for PHP 8.2.
Derick Rethans 0:44: However, back to today, PHP eight one is going to be released today, November 25. In this episode, I'll look back at the previous episodes this year to highlight a new features that are being introduced in PHP 8.1. I am not revisiting the proposals that did not end up making it into PHP 8.1 feature two features I will let my original interview speak. I think you will hear Nikita Popov a lot as he's been so prolific, proposing and implementing many of the features of this new release. However, in the first episode of the year, I spoke with Larry about enumerations, which he was proposing together with Ilija Tovilo. I asked him what enumerations are.
Larry Garfield 1:26: Enumerations, or enums, are a feature of a lot of programming languages. What they look like varies a lot depending on the language, but the basic concept is creating a type that has a fixed finite set of possible values. The classic example is booleans. Boolean is a type that has two and only two possible values true and false. Enumerations are way to let you define your own types like that, to say this type has two values Sort Ascending or Sort Descending. This type has four values for the four different card suits, and a standard card deck. Or a user can be in one of four states pending, approved, cancelled or active. And so those are the four possible values that this variable type can have. What that looks like varies widely depending on the language. In a language like C or C++, it's just a thin layer on top of integer constants, which means they get compiled away to introduce at compile time, and they don't actually do all that much they're a little bit to help for reading. On the other end of the spectrum, you have languages like rust or Swift, where enumerations are a robust, advanced data type and data construct of their own. That also supports algebraic data types. We'll get into that a bit more later. And is a core part of how a lot of the system actually works in practice, and a lot of other languages are somewhere in the middle. Our goal with this RFC is to give PHP more towards the advanced end of enumerations. Because there are perfectly good use cases for it, so let's not cheap out on it.
Derick Rethans 3:14: In the next episode, I spoke with Aaron Piotrowski about another big new feature: fibres.
Aaron Piotrowski 3:20: A few other languages already have Fibers like Ruby. And they're sort of similar to threads in that they contain a separate call stack and a separate memory stack. But they differ from threads in that they exist only within a single process and that they have to be switched to cooperatively by that process rather than pre-emptively by the OS like threads. And so the main motivation behind wanting to add this feature is to make asynchronous programming in PHP much easier and eliminate the distinction that usually exists between async code that has these promises and synchronous code that we're all used to.
Derick Rethans 4:03: I also asked Aaron about small PHP I actually have a slightly related question that pops into my head as like. There's also something called Swoole PHP, which does something similar but from what I understand actually allows things to run in threats. How would you compare these two frameworks or approaches is probably the better word?
Aaron Piotrowski 4:25: Swoole is they try and be the Swiss Army Knife in a lot of ways where they provide tools to do just about everything. And they provide a lot of opinionated API's for things that in this case, I'm trying to provide just the lowest level just the only the very necessary tools that would be required in core to implement Fibers.
Derick Rethans 4:48: Although I discussed several deprecations from Nikita and the last year, I only want to focus on the new features. In episode 76. I spoke with him about array unpacking, after talking about changes to Null in internal functions.
Nikita Popov 5:01: The old background is set we have unpacking calls. If you have the arguments for the call in an array, then you write the free dots and the array is unpacked intellectual arguments. Now what this RFC is about is to do same change for array unpacking, so allow you to also use string keys.
Derick Rethans 5:24: In another episode, I spoke with David Gebler on a more specific addition of a new function fsync. David explains the reason why he wants to add this to PHP.
David Gebler 5:34: It's an interesting question, I suppose in one sense, I've always felt that the absence of fsync and some interface to fsync is provided by most other high level languages has always been something of an oversight in PHP. But the other reason was that it was an exercise for me in familiarizing myself with PHP core getting to learn the source code. And it's a very small contribution, but it's one that I feel is potentially useful. And it was easy for me to do as a learning exercise.
Derick Rethans 5:58: And that is how things are added to PHP sometimes, to learn something new and add something useful at the same time. After discussing the move of the PHP documentation to GIT an episode 78, in Episode 79, I spoke with Nikita about his new in initializers RFC. He says:
Nikita Popov 6:15: So my addition is a very small one, actually, my own will, I'm only allowing a single new thing and that's using new. So you can use new whatever as a parameter default, property default, and so on.
Derick Rethans 6:29: The addition of this change also makes it possible to use nested attributes. Nikita explains:
Nikita Popov 6:34: I have to be honest, I didn't think about attributes at all, when writing this proposal. What I had in mind is mainly parameter defaults and property defaults. But yeah, attribute arguments also use the same mechanism and are under the same limitations. So now you can use new as an attribute argument. And this can be used to effectively nest attributes.
Derick Rethans 6:59: Static Analysis tools are used more and more with PHP, and I spoke to the authors of the two main tools, Matt Brown, of Psalm, and Ondrej Mirtes of PHPStan. They propose to get her to add a new return type called noreturn. I asked him what it does and what it is used for.
Ondrej Mirtes 7:14: Right now the PHP community most likely waits for someone to implement generics and intersection types, which are also widely adopted in PHP docs. But there's also noreturn, a little bit more subtle concept that would also benefit from being in the language. It marks functions and methods that ...