Re: [PHP-DEV] Class Extension

On 10 July 2026 13:46:08 BST, Holly Schilling <[email protected]> wrote:
>
>Now knowing that, it makes the case for using a different keyword like `extension` much stronger since that is not the case for an extension. Everything on an extension is type-checked at compile time, save some edge cases with scalars. 

I'm not sure if I'm misunderstanding, but if you're saying that every reference to $this in the body of an extension method will be analysed by the compiler against the class definition, that would be extremely surprising to PHP users. 

As far as I know, *all* method and property despatch in PHP is dynamic, whether it's on $this or any other object reference. In other words, only when you actually *run* code like $this->whatever() does PHP even try to look for the method definition.

Trying to validate that at compile time would presumably break any dynamic code - $this->whatever() would not be allowed to fall back to __call('whatever'), and $this->{$someVar}() would have to refuse to compile.

While we could argue whether those features make PHP better or worse, having them forbidden just in the context of extension methods would feel very arbitrary.

However, perhaps we're talking at cross purposes, and this is not actually what you're proposing.

Regards,

Rowan Tommins
[IMSoP]