Thank your Levi for your explanation. 2017-05-17 16:47 GMT+02:00 Levi Morrison <le...@php.net>:
> > > On Wed, May 17, 2017 at 4:34 AM, Michał Brzuchalski < > mic...@brzuchalski.com> wrote: > >> Hi everyone, >> >> I would like to put Object Type RFC up to a vote for inclusion in PHP 7.2. >> >> Previously there were some concerns about adding named types in the >> future, >> but we came to the conclusion that each of them can be solved if there are >> proposals in the future. >> >> Voting starts today, 2017-05-17, and will close after two weeks on the >> Wednesday 2017-05-31 at midnight. >> >> The RFC and voting widget can be found here: https://wiki.php.net/ >> rfc/object-typehint <https://wiki.php.net/rfc/object-typehint> >> >> The vote is a straight Yes/No vote for accepting the RFC and merging the >> patch which require 2/3 majority. >> The additional vote is also a straight Yes/No vote for accepting variance >> behaviour on the object type which also require 2/3 majority. >> >> Thanks! >> -- >> regards / pozdrawiam, >> -- >> Michał Brzuchalski >> about.me/brzuchal >> brzuchalski.com >> > > An emphatic "no" on variance for me. This is for two over-arching reasons: > > 1. Object variance should be implemented when we have generalized > variance for all types. By special casing it now we open ourselves to the > possibility that its implementation or semantics will differ from the > generalized solution. > > 2. The way it is implemented prevents us from adding new types which are > not objects. The reason is that the way this is implemented it just assumes > that an unknown type is an object type. If we add a feature such as an > enumerations (enums) this assumption probably breaks and cannot be fixed > while maintaining BC as it would almost certainly need to trigger an > autoload. > > We were thinking about enumerations and generally IMHO, they can be implemented as objects though. Especially when taking Java pattern http://docs.oracle.com/javase/tutorial/java/javaOO/enum.html when dealing with enumeration means dealing with a special purpose and special kind of objects, which are IMO more powerful with methods which can implement some behaviour. > Given these two points I think it's unwise to implement variance as > outlined. I highly encourage other voters to vote against that portion of > the RFC. > > ----- > > Lastly, I want to thank Dan and Michal for working on this RFC as an > object type even without variance would have been useful for me in the past. > -- regards / pozdrawiam, -- Michał Brzuchalski about.me/brzuchal brzuchalski.com
