Code Generators In Swift (Part 2)

Talk about code generators in general, and what code generators we can and should use when we're working with ios projects

1. Code Generators in Swift by Paul Taykalo, Stanfy Code Generators in Swift, #Cocoaheads, Minsk 1
2. Code generation Code Generators in Swift, #Cocoaheads, Minsk 2
3. Code generation or Automatic Programming In computer science, the term automatic programming identifies a type of computer programming in which some mechanism generates a computer program to allow human programmers to write the code at a higher abstraction level — Wikipedia Code Generators in Swift, #Cocoaheads, Minsk 3
4. Generators in general Code Generators in Swift, #Cocoaheads, Minsk 4
5. Our main interest today * Code Generators in Swift, #Cocoaheads, Minsk 5
6. Our goals Code Generators in Swift, #Cocoaheads, Minsk 6
7. Write less code Code Generators in Swift, #Cocoaheads, Minsk 7
8. Automate Repetitive Operations Code Generators in Swift, #Cocoaheads, Minsk 8
9. Save time Make everyone happy Code Generators in Swift, #Cocoaheads, Minsk 9
10. Uniform structure Code Generators in Swift, #Cocoaheads, Minsk 10
11. Error Scalability Code Generators in Swift, #Cocoaheads, Minsk 11
12. Platform Scalability Code Generators in Swift, #Cocoaheads, Minsk 12
13. When should we write one? Code Generators in Swift, #Cocoaheads, Minsk 13
14. When should we write one? ✅ Structure is well defined Code Generators in Swift, #Cocoaheads, Minsk 14
15. When should we write one? ✅ Structure is well defined ✅ Number of special cases is low ✅ Uniform structure Code Generators in Swift, #Cocoaheads, Minsk 15
16. When should we write one? ✅ Structure is well defined ✅ Number of special cases is low ✅ Uniform structure ✅ One Layer of Abstraction Code Generators in Swift, #Cocoaheads, Minsk 16
17. When should we write one? ✅ Structure is well defined ✅ Number of special cases is low ✅ Uniform structure ✅ One Layer of Abstraction ✅ It's time efficient Code Generators in Swift, #Cocoaheads, Minsk 17
18. Time efficiency rule Code Generators in Swift, #Cocoaheads, Minsk 18
19. Time efficiency rule Code Generators in Swift, #Cocoaheads, Minsk 19
20. Time efficiency rule examples Code Generators in Swift, #Cocoaheads, Minsk 20
21. Time efficiency rule examples Code Generators in Swift, #Cocoaheads, Minsk 21
22. Flow time is limited. Simple operations should take small amount of time Code Generators in Swift, #Cocoaheads, Minsk 22
23. Code Generators in Swift, #Cocoaheads, Minsk 23
24. Source Code Generators in Swift, #Cocoaheads, Minsk 24
25. Generator Source DSL Code Generators in Swift, #Cocoaheads, Minsk 25
26. Generator Source Swift Code Code Generators in Swift, #Cocoaheads, Minsk 26
27. Let's back to swift Code Generators in Swift, #Cocoaheads, Minsk 27
28. But before that What so special in code generators for Swift? Code Generators in Swift, #Cocoaheads, Minsk 28
29. What so special in code generators for Swift? • No Runtime • Static Typing • No simple way to get types in runtime* • Hard to get metainformation at runtime* Code Generators in Swift, #Cocoaheads, Minsk 29
30. Examples Code Generators in Swift, #Cocoaheads, Minsk 30
31. Code Snippets Code Generators in Swift, #Cocoaheads, Minsk 31
32. Code Generators in Swift, #Cocoaheads, Minsk 32
33. Xcode File Templates Code Generators in Swift, #Cocoaheads, Minsk 33
34. Project Templates Code Generators in Swift, #Cocoaheads, Minsk 34
35. Bit more complex examples Code Generators in Swift, #Cocoaheads, Minsk 35
36. Swagger • Source Language: DSL in YAML / JSON • Written In: Java • Generates: Everything http://swagger.io/ Code Generators in Swift, #Cocoaheads, Minsk 36
37. Cuckoo • Source Language: Swift Code • Written in: Swift • Generates: Swift (Mocks) https://github.com/SwiftKit/ Cuckoo Code Generators in Swift, #Cocoaheads, Minsk 37
38. Cuckoo let mock = MockGreeter() stub(mock) { stub in when(stub.greetWithMessage("Hello world")).then { message in print(message) } } Code Generators in Swift, #Cocoaheads, Minsk 38
39. VIPER Module Generator • Source Language: String • Written in: Ruby • Generates: Swift, Objective-C https://github.com/teambox/ viper-module-generator Code Generators in Swift, #Cocoaheads, Minsk 39
40. Generamba • Source Language: Ruby (DSL) • Written in: Ruby • Generates: Swift, Objective-C, Xcode Project https://github.com/rambler-digital-solutions/ Generamba Code Generators in Swift, #Cocoaheads, Minsk 40
41. Protobuf Source: Protocol Buffers Language Written in: * Generates: Swift, Any Supported Language https://github.com/alexeyxo/protobuf-swift https://github.com/google/protobuf Code Generators in Swift, #Cocoaheads, Minsk 41
42. SwiftGen Source: Xcode Files Written in : Swift Generates: Enums for resources https://github.com/AliSoftware/SwiftGen Code Generators in Swift, #Cocoaheads, Minsk 42
43. SwiftGen // The Image type below is typealias'ed to UIImage on iOS and NSImage on OSX enum Asset: String { case Green_Apple = "Green-Apple" case Red_Apple = "Red apple" case _2_Pears = "2-pears" var image: Image { return Image(asset: self) } } extension Image { convenience init!(asset: Asset) { self.init(named: asset.rawValue) } } Code Generators in Swift, #Cocoaheads, Minsk 43
44. R Source: Xcode Project Files Written in : Swift Generates: Enums for resources https://github.com/mac-cain13/R.swift Code Generators in Swift, #Cocoaheads, Minsk 44
45. R Code Generators in Swift, #Cocoaheads, Minsk 45
46. Helium Source : DSL in Groovy Written in : JVM Languages Java/Kotlin/Groovy Generates: Java Library, API Client, Swift, Objective-C https://github.com/stanfy/ helium Code Generators in Swift, #Cocoaheads, Minsk 46
47. If you decided to create on Code Generators in Swift, #Cocoaheads, Minsk 47
48. Templates, DSL Code Generators in Swift, #Cocoaheads, Minsk 48
49. SourceKitten Code Generators in Swift, #Cocoaheads, Minsk 49
50. SourceKitten [{ "descriptionKey" : "advancedBy(n: Distance)", "associatedUSRs" : "s:FSi10advancedByFSiFSiSi ", "kind" : "source.lang.swift.decl.function.method.instance", "sourcetext" : "advancedBy(<#T##n: Distance##Distance#>)", "context" : "source.codecompletion.context.thisclass", "typeName" : "Int", "moduleName" : "Swift", "name" : "advancedBy(n: Distance)" }, Code Generators in Swift, #Cocoaheads, Minsk 50
51. SourceKitten sourcekitten structure --text "struct A { func b() {} } { "key.substructure" : [ { "key.kind" : "source.lang.swift.decl.struct", "key.offset" : 0, "key.nameoffset" : 7, "key.namelength" : 1, "key.bodyoffset" : 10, "key.bodylength" : 13, "key.length" : 24, "key.substructure" : [ ... } ], "key.offset" : 0, "key.diagnostic_stage" : "source.diagnostic.stage.swift.parse", "key.length" : 24 } Code Generators in Swift, #Cocoaheads, Minsk 51
52. Tips and Tricks Code Generators in Swift, #Cocoaheads, Minsk 52
53. Don't go too deep Code Generators in Swift, #Cocoaheads, Minsk 53
54. Simple is better than easy Code Generators in Swift, #Cocoaheads, Minsk 54
55. Simple is better than easy • Simple is easier to support and understand Code Generators in Swift, #Cocoaheads, Minsk 55
56. Simple is better than easy • Simple is easier to support and understand • Easy one can be complex but easy to use Code Generators in Swift, #Cocoaheads, Minsk 56
57. Simple is better than easy • Simple is easier to support and understand • Easy one can be complex but easy to use • Use templates Code Generators in Swift, #Cocoaheads, Minsk 57
58. Check reality Code Generators in Swift, #Cocoaheads, Minsk 58
59. Check reality • Ask if this tool is really needed? • Ask other people too Code Generators in Swift, #Cocoaheads, Minsk 59
60. For the future generations • Document • Open Source Code Generators in Swift, #Cocoaheads, Minsk 60
61. Our results Code Generators in Swift, #Cocoaheads, Minsk 61
62. Source type 'Shop' message { shop_id 'string' image 'string' name 'string' description 'string' currency 'string' optional service_charge 'AdditionalCharges' optional payment_methods(type:'PaymentMethod') { sequence true required false } } Code Generators in Swift, #Cocoaheads, Minsk 62
63. Source type "dayOfWeek" spec { constraints("string") { enumeration 'sun', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat' } } Code Generators in Swift, #Cocoaheads, Minsk 63
64. Entities generation public enum DayOfWeek: String { case Sun = "sun" case Mon = "mon" case Tue = "tue" case Wed = "wed" case Thu = "thu" case Fri = "fri" case Sat = "sat" } Code Generators in Swift, #Cocoaheads, Minsk 64
65. Entities generation public struct Shop { public let shopId: String public let image: String public let name: String public let description: String public let currency: String? public let serviceCharge: AdditionalCharges? public let paymentMethods: [PaymentMethod]? } Code Generators in Swift, #Cocoaheads, Minsk 65
66. Equatable // MARK: - Shop Equatable public func == (lhs: Shop, rhs: Shop) -> Bool { return lhs.shopId == rhs.shopId && lhs.image == rhs.image && lhs.name == rhs.name && lhs.description == rhs.description && lhs.currency == rhs.currency && lhs.serviceCharge == rhs.serviceCharge && lhs.paymentMethods == rhs.paymentMethods } Code Generators in Swift, #Cocoaheads, Minsk 66
67. Mappings generation extension DayOfWeek: Decodable {} extension Shop: Decodable { public static func decode(json: AnyObject) throws -> Shop { return try Shop( internalId: json =>? "internal_id" , shopId: json => "shop_id" , image: json => "image" , name: json => "name" , description: json => "description" , currency: json =>? "currency" , deliveryCharge: json =>? "delivery_charge" , paymentMethods: json =>? "payment_methods" ) } } Code Generators in Swift, #Cocoaheads, Minsk 67
68. Random structures generation extension Shop: Random { static func random() -> Shop { return restrictedRandom() } } Code Generators in Swift, #Cocoaheads, Minsk 68
69. Random structures generation extension Shop: Random { static func restrictedRandom( shopId: String = .random(), image: String = .random(), name: String = .random() ... ) -> Shop { return Shop( shopId: shopId, image: image, name: name ... ) } } Code Generators in Swift, #Cocoaheads, Minsk 69
70. Structures updates extension Shop { func updated( shopId: Optional<String> = nil, image: Optional<String> = nil, name: Optional<String> = nil ... ) -> Shop { return Shop( shopId:shopId ?? self.shopId, image:image ?? self.image, name:name ?? self.name ... ) } } Code Generators in Swift, #Cocoaheads, Minsk 70
71. Generated code in action // Only shipId will be set up let validShop = Shop.restrictedRandom( shopId: "SE2016", currency: "UAH" ) // Everything will be copied but 'shopID' property let anotherShop = validShop.updated(shopId:"123") // If we want to set up nil value let notSavedYet = validShop.updated(internalId: Optional(nil)) let notSavedYet2 = validShop.updated(internalId: .Some(nil)) Code Generators in Swift, #Cocoaheads, Minsk 71
72. From one source type 'Shop' message { shop_id 'string' image 'string' name 'string' description 'string' currency 'string' optional service_charge 'AdditionalCharges' optional payment_methods(type:'PaymentMethod') { sequence true required false } } Code Generators in Swift, #Cocoaheads, Minsk 72
73. Sum up • Code generators are here Code Generators in Swift, #Cocoaheads, Minsk 73
74. Sum up • Engineering approach > Art Code Generators in Swift, #Cocoaheads, Minsk 74
75. Sum up • There're always things to automate • Code generation is one of the multiple options Code Generators in Swift, #Cocoaheads, Minsk 75
76. Sum up • Write your own if it worth it • Please don't write another one-time-complex generator • Document well Code Generators in Swift, #Cocoaheads, Minsk 76
77. Thank you Code Generators in Swift, #Cocoaheads, Minsk 77
78. Code Generators in Swift by Paul Taykalo, Stanfy @TT_Kilew Code Generators in Swift, #Cocoaheads, Minsk 78
79. The end Code Generators in Swift, #Cocoaheads, Minsk 79