Re: [RFC] [Discussion] Optional interfaces

Hello Juris, There is some uncertainty for me on how this approach would work with namespaces. Let's get this example: https://3v4l.org/bI1Rj I would expect to get the error message that I forgot to insert `use Stringable;`. But with your idea everything is fine. I don't like such ambiguity and I worry it may bring some confusion to developers. Kind regards, Jorg On Sat, Dec 28, 2024 at 9:57 PM Juris Evertovskis <juris@glaive.pro> wrote: > Hi, > > > > I would like to propose a new syntax that let’s you implement an interface > only if it exists. > > > > class MyClass extends ?OptionalInterface {} > > > > If the OptionalInterface exists, the class implements it. If no > such > interface can be found, it is ignored. > > > > https://wiki.php.net/rfc/optional-interfaces > > > > The need to declare compatibility with a certain interface without > requiring the interface itself comes up when you’re writing code that > should work with various versions of other libraries or PHP itself and when > a library provides interoperability with some other library or a PHP > extension, but does not require it. > > > > Although this would mainly be used by library developers, the consumers of > those libraries would also benefit as this syntax would clearly communicate > the intention of optional interoperability. IDEs and static analysis tools > could also have easier time with ?OptionalInterface instead of > class > definitions inside an if (interface_exists(…)) { … } else > {…}. > > > > I’ve not entirely sure about the naming as an “optional interface” feels > like an oxymoron. I’ve also considered names like non-required interfaces, > conditional interfaces, optional/conditional implementation or even soft > interfaces/soft implementation. Please let me know if the naming itself > bothers you. > > > > Previous discussion: https://externals.io/message/125967 > > WIP implementation: https://github.com/php/php-src/pull/17288 > > > > Looking forward to your feedback and suggestions! > > Juris >