Re: [PHP-DEV] [RFC] Primary Constructors

On Mon, Jun 29, 2026, at 12:27, Lynn wrote:
> 
> 
> On Mon, Jun 29, 2026 at 2:20 AM Rob Landers <[email protected]> wrote:
>> __
>> Hello internals,
>> 
>> I'd like to put forward Primary Constructors <https://wiki.php.net/rfc/primary-constructors> for comment.
>> 
>> An implementation PR will be opened later today (UTC), and the RFC updated with this discussion thread.
>> 
>> — Rob
> 
> I don't see any mention of anonymous classes, I assume they aren't compatible syntax wise? 

Hi Lynn,

That's a good observation! Originally, I had a whole section and decided to strip it, then forgot to add it back as non-supported and future scope. FWIW, I was originally going to support them with something like:

$arg = 'foo';
$class = new class(public int $x = $arg) {}

Which desugars to:

$arg = 'foo';
$class = new class($arg) {
  public function __construct(public int $x) {}
}

There are a lot of caveats, which is why I dropped it for future scope:
 1. it would require types on the input parameters to disambiguate between arguments and properties
 2. it gets weird if you don't specify a default value for the property and makes it ambiguous as a constructor
 3. which begs the question of always having a default
In essence, it deserves its own RFC because there is a lot of subtlety and only makes sense in the context that primary constructors exist in the first place.

I'll address it in the RFC, thanks!

— Rob