Development on Kotlin/Native and Swift

Presented on mDevMeet 2021

Transcript

1. Aydar Mukhametzyanov, JetBrains Development on Kotlin/Native and Swift New technologies and their internals
2. Agenda New technologies in tooling for Kotlin/Native Memory model and concurrency in Kotlin/Native 2
3. About me 2012 2019 iOS RMR, 2GIS, Freeletics JetBrains AppCode 3
4. Kotlin Multiplatform 4
5. Kotlin Multiplatform Mobile 5
6. Kotlin Multiplatform Mobile + Run | Debug | Test iOS 6
7. Kotlin Multiplatform Mobile Problems of an iOS-developer 7
8. Kotlin Multiplatform Mobile Shared.framework ⌨ New code ⏳ Build project 8 Problems of an iOS-developer
9. Kotlin Multiplatform Mobile 9 class MyClass { fun hello() = "Hello from Kotlin!" } let a = MyClass() Problems of an iOS-developer
10. Kotlin Multiplatform Mobile 10 / / . . . _ _ attribute __ ((swift_name("KotlinDouble"))) @interface KNFDouble : KNFNumber - (instancetype)initWithDouble:(double)value; + (instancetype)numberWithDouble:(double)value; @end; _ _ attribute __ ((swift_name("KotlinBoolean"))) @interface KNFBoolean : KNFNumber - (instancetype)initWithBool:(BOOL)value; + (instancetype)numberWithBool:(BOOL)value; @end; _ _ attribute __ ((objc_subclassing_restricted)) _ _ attribute __ ((swift_name("MyClass"))) @interface KNFMyClass : KNFBase - (instancetype)init _ _ attribute __ ((swift_name("init()"))) __ attribute __ ((objc_designated_initializer)); + (instancetype)new __ attribute _ _ ((availability(swift, unavailable, message="use object initializers instead"))); - (NSString *)hello __ attribute _ _ ((swift_name("hello()"))); @end; Problems of an iOS-developer
11. Kotlin Multiplatform Mobile 11 Cmd+Shift+F Problems of an iOS-developer
12. Kotlin Multiplatform Mobile 12 • Lack of Swift and Obj-C support in Android Studio • Necessity to rebuild the framework every time you change the interface • Complicated relation between declaration in Kotlin and usage in Swift Problems of an iOS-developer
14. Kotlin/Native plugin for AppCode 2018 The fi rst release Development on Kotlin/Native in AppCode Highlighting, autocompletion Run | Debug iOS Integration with a wizard 14
15. 2018 15
16. Shared.framework ⌨ New code ⏳ Build project 16 Kotlin/Native plugin for AppCode
17. 17 Kotlin/Native plugin for AppCode
18. What is a symbol Symbol • Name • Location • Attributes • Relations with other symbols • … 18 Internal representation of the declaration of anything in the code. Symbol tables - the IDE's knowledge of classes, functions, variables, etc.
19. class Person { let name = "John" let surname = "Doe" let age = 42 // Very important function func greet() { print("Hi \(name)!") } } class Person let name: String let surname: String let age: Int func greet() -> Void Symbol table 19 What is a symbol
20. Obj-C - Swift Cross Resolve Obj-C class AnotherObject: NSObject @interface AnotherObject : NSObject //... @end Naming Rules 20
21. Cross Resolve 21 Kotlin-Swift Cross Resolve
22. Symbols translation val helloString = "Hello from Kotlin!" var helloString: String { get } 22
23. MyShared.framework MyFramework.h MyFramework IDE Old approach val helloString = "Hello from Kotlin!" @property (readonly) NSString *helloString; objc var helloString: String { get } Kotlin compiler ⏳ Build project 23 Symbols translation
24. Kotlin compiler 24 Kotlin frontend Kotlin/Native backend Kotlin 
 Code Module Descriptors MyShared.framework MyFramework.h MyFramework Symbols translation
25. Kotlin/Native backend 25 Module Descriptors MyShared.framework MyFramework.h MyFramework Obj-C Symbol Structures Obj-C Symbols Swift Symbols Symbols translation
26. IDE New approach val helloString = "Hello from Kotlin!" var helloString: String { get } Internal Compiler Structures @property (readonly) NSString *helloString; objc New 26 Symbols translation
27. Advantages of the new approach 🚀 Updates on the fl y 🎯 Go to Declaration, refactorings and etc. 😅 Forgives mistakes 27 Symbols translation
28. Hooray! 
 Now you don't have to rebuild the framework after each Kotlin code change! 28 print(a.hello) SourceKit
29. Getting annotations from SourceKit What is SourceKit SourceKit request response Navigation Highlighting Autocompletion … 29
30. 30 val helloString = "Hello!" Create property SourceKit import MyFramework Open Swift fi le Getting annotations from SourceKit Problem
31. 31 Open Swift usage print(a.hello) val hello = "Hello!" Rename val helloString = "Hello!" Create property print(a.helloString) Use in Swift @property (readonly) NSString *helloString; MyFramework.h Build SourceKit Getting annotations from SourceKit Problem
32. 32 📁 MyFramework.framework/ 📁 Headers/ MyFramework.h 📁 Modules/ module.modulemap Info.plist MyFramework SourceKit Getting annotations from SourceKit Solution
33. 33 📁 MyFramework.framework/ 📁 Headers/ MyFramework.h 📁 Modules/ module.modulemap SourceKit After each Kotlin code change ~/Library/Caches/…/DerivedData/MyApp-byxnfgfeahmhpthjejgycztlpstg/SourceKitFrameworkStubs/MyFramework.framework Getting annotations from SourceKit Solution
34. Optimizations 34 • Generate right before the opening of a Swift fi le • Ignore changes in comments and function bodies / / This is very important fun doImportantThings(): Int { val a = 1 val b = 2 return a + b } Getting annotations from SourceKit
35. Plugin use 35
36. Conclusions 36 In the future, Kotlin Multiplatform will become increasingly friendly to iOS developers
37. 37 Cross-resolve between Kotlin and Swift already exists, and you can try it right now in Kotlin/Native plugin for AppCode Conclusions
38. 38 In the KMP world, it is very useful to know Gradle, even if you develop iOS apps Conclusions
39. Thank you! 39 What we talked about: • KMP intro • Current problems of the iOS world • Kotlin/Native plugin for AppCode • How Kotlin-Swift cross-resolve works • SourceKit problem and how it’s solved • Conclusions @appcode @aydarmukh