On Sun, 14 Mar 2021 at 12:02, Gert de Pagter <gert...@gmail.com> wrote:
> Hey Internals, > > Recently i've been working on an older code base, where we have a lot > of classes with all > static methods. We've been moving to injecting the classes, and > calling the methods as if they > were not static. > > I wanted to add interfaces to these classes, with non static methods, > so we can pretend in our implementation they are not static, and allow > us to easier switch to non static methods in the future. > > This is (currently) not allowed by the language: https://3v4l.org/WKdvM > Is there any chance of this being possible in future versions of PHP? > This would only allow 'normal' methods to become static. Making static > methods non static would break Liskov substitution principle in PHP as > you may not be able to call the method in the same way. This means you > can't have a 'normal' method become static in an inherited class, and > then become 'normal' again in another inherited class. This works the > same way with co/contra-variance in return/parameter types: > (https://3v4l.org/j1SO9) > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: https://www.php.net/unsub.php > > It's maybe possible in the special case of implementing interfaces, but it's unsound for general inheritance: <?php class A { public int $someInt = 0; public function getSomeInt() : int { return $this->someInt; } } class B extends A { public static function getSomeInt() : int { return parent::getSomeInt(); } } https://3v4l.org/WnaES
