Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:128388
Message-ID: <1c1aa775-07d1-4f0f-889c-4d801f7ceadf@nunninger.info>
Date: Mon, 4 Aug 2025 19:46:26 +0200
Precedence: list
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PHP-DEV] Blog post: If we can get partial generics, should we?
To: Larry Garfield <larry@garfieldtech.com>,
 php internals <internals@lists.php.net>
References: <c8a2439d-2690-4e0e-a13b-718714728bd5@app.fastmail.com>
Content-Language: de-DE-frami, en-US
In-Reply-To: <c8a2439d-2690-4e0e-a13b-718714728bd5@app.fastmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
UI-OutboundReport: notjunk:1;M01:P0:BR2qHyp3E/c=;NI08oJL0SbP0ewoX7/8CL2El9Ag
 3vUgYu7F4JR74g8FYlw2UtNryVJYRkd/ibpFE8tYW7a8HqFaNfRsM7N/B2gxKKiiRwF/qi+l+
 SD1i/w6FbhiLrCeEATQ1CTx46dSZCqeqVLUMfkMC6yFZMJ8jP+crZUTyEbcTzF6EZiv0dEJvp
 rwilVI9QZ6F1JEp0ynzqyJYCrs603fazmv040zols5jsR6QR00zlUC6jXhd5f7xmGEu5xkBYl
 8UDvYcL6FSfu8T6I9krXHrUnsfkR4eT8ZG6VaiRv6tRw4X+0K7hAYJQebO6OCMR9Vn8GvBfxy
 5qDCLgSfXHzz+AMl+qdHor6BeabjdKxxx/w+TyGflWzvKD+oOzwyJmcWZbjc8XsXTc6wQcYj8
 64xVAy201FUsqIAK3sM4p3ldGoiW5cHGk4XwOAthKBMRwuDLn+JC5Fjtt5nF7xeDasIIo/0Tf
 LZ3hZyr9dCHGVDCf9QGMiAVXtIlv9ftVOijoBZEGwbTaXpiyjubU+npQGdAKrmlJbrKLKBCwJ
 4LgqILBU+VqmHUQ9CGQNez7VtoqIWK/75kQtmkwYSjrxSAx79oCmzhTaZhQwhh2ldNsGlwrY6
 zgzSshV68EVdEQ9CP2Pxyxxxaj6kei1dblduPNapTIQeskzyT1bB5XCok/Qa+L6iM+kcLtsTw
 cw2sbr5YMPDU6XYTtZ+kltWsvEWt2qIpVla5tYYz1M7vzNRZZ9b41ApTnpDXcmINmov4/zqAU
 LytlWs8saOyhtgWajBsLzHJsBafIu/dkafrpRz7mpPsrhW1toxbbTWVfehAn9MtkHp8C/CYw8
 KR745K0HOZNYxAl4Dh0QKzv8feUlZeygxYrrT6YShdJyICuf110SCGA4DEleAMVAwJGvNXvL/
 Ngq49PJvB7svL63JnQg7l55Q/jwlz565ndMUqR5MDwmiwOMjDZmagp5kSA4CVsSEWMU6Oqq/2
 i/9lvOI8k++4MhJWKr1Fa+pN/e4MgD5cH3Y2MgAERLO6uU9oIiO+asqVhdhzhoflHbBf5E0ID
 W8238Swm27tSgTsoFYnT++uDE/ijvQxmPsE0Z0kpIwwTk1n5yHlBvsXQYUloxtB6gSQDxNx0D
 Pj81J0CvyphMNvyW9uReyNZMyKI9mI6JoDewVHgjZINaLyCAdSjPyKXsgPuC7Oc1Nf4tjNABC
 b5XgLz+InpIP4G/8nLNVh6WYIqG3IrXCMiU7I+eRYTv/Bj/qcCG2K2z7Lm2ejzfKK3sABUijj
 19aSf5aa/7LkylAqjLiAUv7GsFc2Kl6BQuTOnR/WDwQUlwzM1+xLDPp/Pkj9hUgPT4dDmw1wZ
 65yDBRGpmghBkPJV7b+6WrZQHnEqlkYGH5g47WnsM8u6iMdZljcYhrJPHgNXIW+AUJwLBMIlb
 J23XIUEUxx0jnankptWPy8/XehcW+/vEZqnt3nt15JZeJJedvFMp7LDMstNerpE0rocfW98GF
 6y306PzJrBouOp8m+fp9aGjpROrKlaHILpXpkKn9mZDuJVMq/mrQCgeR+wtxysAg9ijxjhnh2
 Y+WaKf4Rz4nNbYeFSrEhkOuGboaR2o6TBibmd92Nvmtukwu+hSGB7c2Osfi/eg==
From: thomas@nunninger.info (Thomas Nunninger)

Hi,

Am 04.08.25 um 17:23 schrieb Larry Garfield:
> Hi folks.  I recently wrote a blog post on behalf of the PHP Foundation about some work Gina has been doing regarding generics.  It's a follow-up to last year's post on a similar topic.  We are especially looking for feedback from the Internals crew, and voters in particular, on whether or not to proceed.
> 
> https://thephp.foundation/blog/2025/08/05/compile-generics/
> 
> Wearing my Internals/voter hat, my stance is a very strong "yes please!"

Thanks for that nice write-up and potentially great improvement.


Can you please elaborate why it wouldn't be possible to create "empty 
extending classes" during compile-time of a file when there is a "`new` 
generic" found?


Some example to make it clearer:


Given a generic class


   ```
   namespace SomeNamespace;

   use Some\Entity;

   abstract class MyGenericClass<T: Entity>
   {
       // ...
   }
   ```


and given an entity


   ```
   namespace MyEntities;

   use Some\Entity;

   class UserEntity extends Entity
   {
       // ...
   }
   ```


when using a "`new` generic" in some file


   ```
   namespace OtherNamespace;

   use SomeNamespace\MyGenericClass;
   use MyEntities\UserEntity;

   $myGenericObject = new MyGenericClass<UserEntity>;
   ```


and when compiling that file


then the compiler creates an "empty extending class" on the fly if there 
is none available in the OpCache (from compiling some other file with 
the same "`new` generic") that has code equivalent to

   ```
   namespace SomeNamespace;

   use MyEntities\UserEntity;

   class MyGenericClass<UserEntity> extends MyGenericClass<Entity>
   {}
   ```


That simply(TM) means, to allow `<` and `>` in class names but only 
internally to the engine and if generated by the compiler itself.


Further question: Would it be possible to automatically mark a class as 
abstract if it is a generic class?


Probably you have thought about this option and I just don't understand 
anything about internals of PHP. So don't hesitate to just answer very 
shortly. ;-)


Best regards
Thomas