I was just thinking about proposing something like this. +1.
Charles > On Aug 22, 2016, at 11:59 PM, Jonathan Hull via swift-evolution > <[email protected]> wrote: > > Hi everyone, > > We talked about this before when we were discussing mixins, and there seemed > to be generally positive feelings towards it as a feature for the future. I > am fairly certain this affects the ABI though, so I thought I would bring it > up now. > > If two protocols have methods/properties with the same name, but different > signatures, we need a way to distinguish between them when attempting to > conform to both. > > protocol A { > var x:Int {get set} > } > > protocol B { > var x:Double {get set} > } > > One possibility is to allow a struct/class/enum to conform to the protocol > while renaming one (or both) of the clashing methods: > > struct C: A,B { > var x:Int > var y:Double implements B.x > } > > The conforming method/property would still have to have the same signature, > but could have a different name (and parameter labels). It would also allow > protocol methods which have identical signatures and semantics, but different > names to be implemented using the same method (i.e ‘implements D.z & E.w’). > > When something is cast to the protocol (say ‘as B’), then calling the > property (e.g. ‘x’) would end up calling the implementation of the renamed > property ( ‘y’ in this example) on the conforming type. > > I think we would also want a way to retroactively conform using existing > properties/methods in an extension declaring conformance. Not sure what the > best syntax for that would be. Off the top of my head (though I would love > to have something with less cruft): > > extension D:B { > @conform(to: B.x, with: D.y) > } > > or maybe just: > > extension D:B { > D.y implements B.x > } > > > All of this is merely to start the discussion, so feel free to propose better > syntax or a more elegant solution... > > Thoughts? > > Thanks, > Jon > > > _______________________________________________ > swift-evolution mailing list > [email protected] > https://lists.swift.org/mailman/listinfo/swift-evolution _______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
