Mixing methods and properties in Swift

test1.swift

protocol Worker {
    func work()
}

struct AnyWorker: Worker {
    
    let work: () -> Void
    
    func work() {
        print("1")
        work()
    }
}

let worker: Worker = AnyWorker {
    print("2")
}

worker.work()

// Does not compile:
//   Invalid redeclaration of 'work()'

test2.swift

protocol Worker {
    func work(task: Any)
}

struct AnyWorker: Worker {
    
    let work: Any -> Void
    
    func work(task: Any) {
        print("1")
        work(task)
    }
}

let worker: Worker = AnyWorker { task in
    print("2")
}

worker.work(Void())

// Prints:
//   1
//   2

test3.swift

protocol Worker {
    func work(task: Any)
}

struct AnyWorker: Worker {
    
    let work: (task: Any) -> Void
    
    func work(task: Any) {
        print("1")
        work(task)
    }
}

let worker: Worker = AnyWorker { task in
    print("2")
}

worker.work(Void())

// Prints:
//   1
//   1
//   1
//   ...
// until task overflow