ADT examples in Swift

direction.swift

enum Direction {
  case Left
  case Right
}

func angle(direction: Direction): Int {
  switch(direction) {
    case Left: return 90
    case Right: return -90
  }
}

result.swift

enum Result<T> {
  case Valid(T)
  case Error(Error)
}

// Because switch statements are not expressions it's best to write this example in
// it's own function
func getAddresses(): [Address] {
  var addresses = [Address]()
  let result = addressesClient.fetchAddresses()

  switch (result) {
    case .Valid(let value): return value
    case .Error(let value): return addresses 
  }
}

let addresses = getAddresses()