patterns.swift

enum MySpecialEnum {
  case someCase
  case someCaseWithAssociatedData(String)
  case someCaseWithNumbers(Int)
}


func handleSpecialEnum(_ value: MySpecialEnum) {
  switch value {
    case .someCase:
      justDoSomething()
    case let .someCaseWithAssociatedData(stringValue) where stringValue == "foo":
      handleFoo()
    case let .someCaseWithAssociatedData(stringValue):
      handleAssociatedData(stringValue)
    case let .someCaseWithNumbers(integerValue) where integerValue < 10:
      handleSmallNumbers(integerValue)
    case let .someCaseWithNumbers(integerValue):
      handleBigNumbers(integerValue)
  }
}