I loved the proposal and I think this has the potential to be a huge developer experience improvement, perhaps at least as great as property constructor promotion and match().
Just a side note though, in the Backward Compatibility section, I would think that only "None" should be declared. From the PHP binary perspective, running code before and after this change has absolutely 0 impact/breaking changes. The feature may introduce a new way for *Users of PHP* to break BC with *Other Users of PHP*. The language change itself has no impact on PHP code written prior to the feature. The additional note about how users may break BC by using the feature would be a description of the feature itself, thus might be best declared as part of the Proposal instead. I wish us all the best of luck with this proposal. On Thu, Jun 15, 2023 at 12:48 AM Levi Morrison via internals < internals@lists.php.net> wrote: > Hello, PHP Internals, > > I am moving my RFC for interface default methods to discussion: > https://wiki.php.net/rfc/interface-default-methods. > > This can be a useful tool for a few reasons: > 1. It can make implementing an interface easier when certain methods > can be implemented by other methods in the interface. For example, if > `Countable` had an `isEmpty(): bool` method, it could be implemented > by doing `$this->count() > 0`. Of course, if an implementation can be > more efficient, they are still free to implement it how they want. > 2. It can mitigate BC breaks in some cases. It's somewhat common for > authors to want to expand new methods onto existing interfaces over > time. Although this would still be a BC break, it moves it from a > massive change (every single implementor must add something, even if > it's a stub, or it will fail to compile) to a naming collision issue > only (only classes which already had a method of the same name will > fail to compile). > > There is prior art for this feature in both Java and C#. There may be > other languages, but I was aware of at least these. > > Note that the RFC links to a partial implementation. If there are two > or more interfaces with default methods of the same shape (name, args, > etc) and a class implements both interfaces and doesn't provide a > concrete implementation, which default implementation should be > chosen? There is a proposal for resolving this in some cases which is > modelled after Java's implementation, but it isn't implemented. > > Thank you for your time. I look forward to productive feedback. > > Levi Morrison > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: https://www.php.net/unsub.php > > -- Marco Deleu
