swift - The Factory Method Pattern

class RentalCar {

private var nameBV:String;

private var passengersBV:Int;

private var priceBV:Float;

private init(name:String,passengers:Int,price:Float) {

self.nameBV = name;

self.passengersBV = passengers;

self.priceBV = price;

}

final var name:String { get { return nameBV; }}

final var passengers:Int { get { return passengersBV; }};

final var pricePerDay:Float { get { return priceBV; }};

class func createRentalCar(passengers:Int) -> RentalCar? {

var carImpl:RentalCar.Type?;

switch (passengers) {

case 0...3:

carImpl = Compact.self;

case 4...8:

carImpl = SUV.self

default:

carImpl = nil;

}

return carImpl?.createRentalCar(passengers);

}

}

class Compact : RentalCar {

private convenience init() {

self.init(name: "VW Golf",passengers: 3,price: 20);

}

private override init(name: String,passengers: Int,price: Float) {

super.init(name: name,passengers: passengers,price: price);

}

override class func createRentalCar(passengers:Int) -> RentalCar? {

if (passengers < 2) {

return sharedInstance;

} else {

return SmallCompact.sharedInstance;

}

}

class var sharedInstance:RentalCar {

get {

struct SingletonWrapper {

static let singleton = Compact();

}

return SingletonWrapper.singleton;

}

}

}

class SmallCompact : Compact {

private init() {

super.init(name: "Ford Fiesta",price: 15);

}

override class var sharedInstance:RentalCar {

get {

struct SingletonWrapper {

static let singleton = SmallCompact();

}

return SingletonWrapper.singleton;

}

}

}

class SUV : RentalCar {

private init() {

super.init(name: "Cadillac Escalade",passengers: 8,price: 75);

}

override class func createRentalCar(passengers:Int) -> RentalCar? {

return SUV();

}

}