Swift -- enum 继承 protocol

原文地址链接：http://blog.csdn.net/duanyipeng/article/details/32338575

Apple官方文档：The Swift Programming Language

Protocols and Extensions一节的小节练习，要求自行定义一个enumeration枚举类型，并且遵循ExampleProtocol协议：

1. protocol ExampleProtocol {
2. var simpleDescription: String { get }
3. mutating func adjust()
4. }

　　// 枚举继承协议

1. enum EnumConformToProtocol: ExampleProtocol {
2. case First(String), Second(String), Third(String)
3. var simpleDescription: String {
4. get {
5. switch self {
6. case let .First(text):
7. return text
8. case let .Second(text):
9. return text
10. case let .Third(text):
11. return text
12. default:
13. return "get error"
14. }
15. }
16. set {
17. switch self {
18. case let .First(text):
19. self = .First(newValue)
20. case let .Second(text):
21. self = .Second(newValue)
22. case let .Third(text):
23. self = .Third(newValue)
24. }
25. }
26. }
27. mutating func adjust() {
28. switch self {
29. case let .First(text):
30. self = .First(text + " (first case adjusted)")
31. case let .Second(text):
32. self = .Second(text + " (second case adjusted)")
33. case let .Third(text):
34. self = .Third(text + " (third case adjusted)")
35. }
36. }
37. }
38. var enumConformToProtocolTest = EnumConformToProtocol.First("FirstVal")
39. enumConformToProtocolTest.simpleDescription
40. enumConformToProtocolTest.adjust()
41. enumConformToProtocolTest.simpleDescription
42. enumConformToProtocolTest = EnumConformToProtocol.Third("ThirdVal")
43. enumConformToProtocolTest.simpleDescription
44. enumConformToProtocolTest.adjust()
45. enumConformToProtocolTest.simpleDescription
46. var e = EnumConformToProtocol.Second("Hello")
47. var text = e.simpleDescription
48. e.simpleDescription = "Adios"
49. text = e.simpleDescription
50. e.adjust()
51. text = e.simpleDescription