class A <P> ;)?
Sent from my iPhone > On 22 Jul 2016, at 18:42, Leonardo Pessoa <[email protected]> wrote: > > It would still cause confusion if you were only to conform to a single > protocol (P in "class A : P" is a class or a protocol?). This can be > solved in code but I don't think it is necessary. > > L > > > On 22 July 2016 at 14:08, Goffredo Marocchi via swift-evolution > <[email protected]> wrote: >> I think that the current approach marks a regression in declarative >> expressiveness as the notion of extending a class over implementing a >> protocol is blurred while the concepts are IMHO not the same (the latter is >> about behaviour conformance not a is a relationship): >> >> Class/struct B : Class/struct A <Protocol1 & Protocol2> >> >> >> would be a clear and concise way to express it that would not be confused >> even at a quick glance. >> >> Sent from my iPhone >> >> On 22 Jul 2016, at 14:47, Charlie Monroe via swift-evolution >> <[email protected]> wrote: >> >> I agree that this is an issue. Mostly nowadays when more and more classes in >> Swift do not have a superclass - it simply looks weird: >> >> class MyClass: DataSource >> >> One doesn't know whether "DataSource" is a class, protocol, etc. >> Nevertheless, I do not feel that :: is the answer. I really liked, how ObjC >> did it (which isn't possible with the generics now - is it?), but what about >> something like this? >> >> class BaseClass [SomeDelegate, OtherDelegate, ProtocolX] >> class MyClass: BaseClass [SomeDelegate, OtherDelegate, ProtocolX] >> extension MyClass [OtherProtocol] >> >> >> On Jul 22, 2016, at 3:14 PM, Vladimir.S via swift-evolution >> <[email protected]> wrote: >> >> >> I remember that this was discussed, but can't find any decision regarding >> this.. So, as a last chance, don't we want in Swift 3.0, as big source >> breaking change, separate class inheritance and protocol conformance in >> syntax? >> >> >> Sorry if there was a decision about this suggestions. Please let know in >> this case. >> >> >> I.e. when I see the following I can't understand if the class inherits from >> base class and conforms to protocols or just conforms to two protocols: >> >> >> class MyClass : First, Second, Third { >> >> } >> >> >> We don't have a rule to name protocols with 'Protocol'/other suffix/prefix, >> or classes with 'T'/'C' prefix or something like this, so I believe to >> improve the clarity of code we should separate in syntax inheritance and >> conformance. >> >> >> As I understand we should discuss changes in these areas: >> >> >> 1. class inheritance : >> >> class Child: BaseClass >> >> >> 2. class conformance : >> >> class Child: SomeProtocol1, SomeProtocol2 >> >> >> 3. class inheritance + conformance : >> >> class Child: BaseClass, SomeProtocol1, SomeProtocol2 >> >> >> 4. protocol conformance for structs: >> >> struct Struct: SomeProtocol1, SomeProtocol2 >> >> >> 5. protocol inheritance: >> >> protocol Child: BaseProtocol1, BaseProtocol2 >> >> >> >> My suggestions: >> >> >> I) separate inheritance with double colon : >> >> >> 1. class inheritance : >> >> class Child:: BaseClass >> >> >> 2. class conformance : >> >> class Child: SomeProtocol1, SomeProtocol2 >> >> >> 3. class inheritance + conformance : >> >> class Child:: BaseClass : SomeProtocol1, SomeProtocol2 >> >> >> 4. protocol conformance for structs: >> >> struct Struct: SomeProtocol1, SomeProtocol2 >> >> >> 5. protocol inheritance: >> >> protocol Child:: BaseProtocol1, BaseProtocol2 >> >> >> >> II) in class definition use parenthesis to separate inheritance and >> conformance : >> >> >> 1. class inheritance : >> >> class Child: BaseClass >> >> >> 2. class conformance : >> >> class Child: (SomeProtocol1, SomeProtocol2) >> >> >> 3. class inheritance + conformance : >> >> class Child: BaseClass (SomeProtocol1, SomeProtocol2) >> >> >> 4. protocol conformance for structs: >> >> struct Struct: SomeProtocol1, SomeProtocol2 >> >> or >> >> struct Struct: (SomeProtocol1, SomeProtocol2) >> >> should be discussed >> >> >> 5. protocol inheritance: >> >> protocol Child: BaseProtocol1, BaseProtocol2 >> >> >> >> III) special word like 'conforms' >> >> >> 1. class inheritance : >> >> class Child: BaseClass >> >> >> 2. class conformance : >> >> class Child: conforms SomeProtocol1, SomeProtocol2 >> >> or >> >> class Child conforms SomeProtocol1, SomeProtocol2 >> >> >> 3. class inheritance + conformance : >> >> class Child: BaseClass conforms SomeProtocol1, SomeProtocol2 >> >> >> 4. protocol conformance for structs: >> >> struct Struct: conforms SomeProtocol1, SomeProtocol2 >> >> or >> >> struct Struct conforms SomeProtocol1, SomeProtocol2 >> >> >> 5. protocol inheritance: >> >> protocol Child: BaseProtocol1, BaseProtocol2 >> >> >> >> Thoughts? >> >> _______________________________________________ >> >> 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 >> >> >> _______________________________________________ >> swift-evolution mailing list >> [email protected] >> https://lists.swift.org/mailman/listinfo/swift-evolution >>
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