Kotlin/Native for Multiplatform development

Kotlin/Native for Multiplatform development presentation at GDG Kyoto Meetup

1. Kotlin/Native for Multiplatform Development Enrique López Mañas
2. Ego Slide • Freelance Dev • Google Developer Expert • KotlinWeekly publisher • @eenriquelopez
3. Motivation < Costs Sharing code within the company Feature teams > Quality One tech-stack
4. Multiplatform development Platform Proprietary Hybrid HTML & JavaScript Frameworks Cross-platform Native
5. Kotlin Modern language
6. Kotlin
7. Kotlin Interop
8. Kotlin Community support
9. Kotlin Top-notch tooling
10. Kotlin Sharing is optional! No life or death commitment
11. Current situation Q2 Q3 Q4 Q1 Q2 v0.7 v0.8 v0.8.2 v0.9.3
12. Kotlin/Anywhere Android Browser Server
13. Kotlin/Native Common JVM Native iOS framework Your iOS dev Your Android Dev JS
14. Kotlin/Native Sharing architecture (not UI) Shared UI is a mess
15. Kotlin/Native - Uses LLVM (5.0) - Provides runtime guarantees - Exceptions, memory management - Interop with C/Objective-C (Swift) - Platform libraries (POSIX, Apple Frameworks, Win32, DOM, etc)
16. Kotlin/Native Kotlin Compiler LLVM Kotlin Source Code (.kt) Platform Binary IR
17. The compiler -Shares Front-end with Kotlin/JVM and Kotlin/JS - Written in Java and Kotlin - Produces bitcode via LLVM API
18. Memory Management - ARC with Cycle Collector - When working pure Kotlin,don’t worry about memory management - Weak references supported - Memory sharing model - Different threads have disjoint object graphs - Object subgraphs can be transferred between threads - Immutable objects can be shared
19. Interoperatibility - Interoperatibility with C, Objective-C and Swift - Kotlin can call C/Objective-C and vice-versa - Kotlin can extend Objective-C classes and vice-versa - Memory management aware of Objective-C runtime
20. Mapping - Numbers are kept - Strings converted - Kotlin declarations wrapping C entities (functions, struct, unions, etc.) are auto- generated - Objective-C OO concepts (classes, protocols, blocks) are represented as matching Kotlin entities (classes interfaces, lambdas) - For Objective-C, Kotlin code can be compiled to a framework
21. Kotlin Library - Hold collection of code for reusability and sharing - Own format: ‘klib’ extension, which holds metadata and bitcode - Tool for creating and storing libraries in repositories
22. Existing native libraries - Ktor - Kotlinx.Coroutines - Kotlinx.io - Atomic-fu
23. Community projects - Sqldelight - Knarch.db - Multiplatform settings - Stately - OKIO2 (under development)
24. expect/actual
25. expect/actual
26. expect/actual
27. expect/actual JVM
28. expect/actual JS
29. Considerations in state An object belongs to one thread
30. Considerations in state Frozen objects can be shared by threads
31. Concurrency - frozen objects Everything you have written until now is not frozen
32. Considerations in state No threading primitives: synchronized, volatile Use atomic-fu instead
33. Considerations in state Runtime safety: Kotlin/Native can verify safe mutability
34. Get started git clone https://github.com/JetBrains/kotlin-native ./gradlew dependencies:update ./gradlew bundle kotlinc hello.kt -o hello -opt
35. The future Hard to make predictions, easier to bet safe “I don’t know what will happen in 10 years, but there will be people asking in SO about regular expressions, and there will be another JS framework ”
36. Flutter vs Kotlin/Native? Flutter - custom UI Widgets Kotlin - more performant Kotlin - better ecosystem
37. Recommendations - Use it with caution - Shared components - Keep versioning in mind - Do not compromise 100% of a project
38. Further resources Kotlin Slack (kotlinlang.slack.com) Touchlab resources (https://github.com/touchlab) Kotlin Weekly (http://kotlinweekly.net) K/N documentation (https://kotlinlang.org/docs/ reference/native-overview.html)