Re: [RFC][Discuss] Covariant return- and contravariant parameter- types

I can only say that I've been waiting for this feature for years and am really looking forward to see it implemented, hopefully in 7.4. Good job on the RFC, I wish you luck! On Mon, 26 Nov 2018 at 22:26, Levi Morrison <levim@php.net> wrote: > I am happy to announce my latest RFC, [Covariant Returns and > Contravariant Parameters][1], is open for discussion. If you do not > recognize those terms then hopefully the introduction coupled with the > [examples][2] will help. Here is one snippet that demonstrates > covariant return types: > > <?php > interface Repository { > function fetch(int $id): ?Entity; > } > > class UserFactory implements Repository { > function fetch(int $id): ?UserEntity { > /* Since UserEntity is an Entity, this is now allowed */ > /* ... implementation ... */ > } > } > ?> > > Covariant return types and contravariant parameter types are highly > requested features; here are a few of the bug reports: > > * https://bugs.php.net/bug.php?id=71825 > * https://bugs.php.net/bug.php?id=72442 > * https://bugs.php.net/bug.php?id=75385 > * https://bugs.php.net/bug.php?id=75823 > > There is a [preliminary implementation][3] that is available. It will > not be rebased during discussion to allow people to check out the code > and get updates without worrying about it breaking. The code quality > can definitely be improved, and there are still a few todo comments in > the code. > > Please do not discuss the items found in [Future Scope][4] as part of > this thread, which includes discussing types such as mixed, > scalar, numeric, etc. > > I look forward to your feedback, and especially with your > experimentation with the implementation. > > Levi Morrison > > [1]: > > https://wiki.php.net/rfc/covariant-returns-and-contravariant-parameters > [2]: > > https://wiki.php.net/rfc/covariant-returns-and-contravariant-parameters#examples > [3]: > > https://github.com/php/php-src/compare/master...morrisonlevi:variance2 > [4]: > > https://wiki.php.net/rfc/covariant-returns-and-contravariant-parameters#future_scope > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: http://www.php.net/unsub.php > >