relates to:

• SR-8524 Shadowing in protocols leads to difficult to find bugs

Issue Description:

Another Team had some trouble tracking down a bug that was finally ruled to be shadowing between a var in a protocol and a let in the implementation. This is made worse than binding shadowing because the protocol might be defined "father" away than the implementation.

protocol CuteAnimal {
  var name: String { get }
}

extension CuteAnimal {
  var name: String { return "Porg" }
}

struct CrystalFoxThing: CuteAnimal {
  let name: String?
  init(name: String) {
    self.name = name
  }
}


let f = CrystalFoxThing(name: "Fox")

func useAnimal(animal: CuteAnimal) {
  print(animal.name)
}

useAnimal(animal: f)

I was also surprised to find that:

protocol CutePetAnimal: CuteAnimal {   var name: String { set } }

Was not allowed but

protocol CutePetAnimal: CuteAnimal {   var name: String { get set } }

Is allowed, which to me adds yet another level of confusing shadowing (I would have expected the
reverse to be true, IE you are extending name with a getter)