K/N for mobile developers (including libraries' snippets)

Transcript

1. K/N for Mobile Citizens Enrique López Mañas
2. Ego Slide • Freelance Dev • Google Developer Expert • KotlinWeekly publisher • @eenriquelopez • Mainly Android Kotlin, Backend Kotlin, iOS (mostly Swift)
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
8. Kotlin Interop
9. Kotlin Community support
10. Kotlin Top-notch tooling
11. Kotlin Sharing is optional! No life or death commitment
12. Current situation Q2 Q3 Q4 Q1 Q2 v0.7 v0.8 v0.8.2 v0.9.3
13. Kotlin/Anywhere Android Browser Server
14. Kotlin/Native Common JVM Native iOS framework Your iOS dev Your Android Dev JS
15. Kotlin/Native Sharing architecture (not UI) Shared UI is a mess
16. 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)
17. Kotlin/Native Kotlin Compiler LLVM Kotlin Source Code (.kt) Platform Binary IR
18. The compiler -Shares Front-end with Kotlin/JVM and Kotlin/JS - Written in Java and Kotlin - Produces bitcode via LLVM API
19. 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
20. 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
21. 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
22. 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
23. Get started git clone https://github.com/JetBrains/kotlin-native ./gradlew dependencies:update ./gradlew bundle kotlinc-native hello.kt -o hello -opt
24. expect/actual
25. expect/actual
26. expect/actual
27. expect/actual JVM
28. expect/actual JS
29. Square JetBrains TouchLab Others
30. Community projects - Sqldelight - Knarch.db - Multiplatform settings - Stately - OKIO2 (under development)
31. Existing native libraries - Ktor - Kotlinx.Coroutines - Kotlinx.io - Atomic-fu
32. ktor - Web application framework -Domain Specific Language (DSL) syntax for web apps-Kotlin coroutines for asynchronous programming -Can be used on web, iOS and Android -Provides a unified toolset with a single language, like Node.js but with type-safety and build-concurrency.
33. ktor
34. ktor
35. ktor
36. ktor
37. ktor
38. Coroutines JetBrains async library
39. Coroutines
40. Coroutines
41. kotlinx.io Library for I/O primitives building and manipulations Experimental
42. kotlinx.io
43. kotlinx.io
44. kotlinx.io
45. AtomicFU Library for atomic operations in Kotlin
46. Considerations in state No threading primitives: synchronized, volatile Use atomic-fu instead
47. AtomicFU
48. AtomicFU
49. AtomicFU
50. SQLiter/SQLager •Evoution of knarch.db •From Touchlab •SQLiter -> SQL Driver •SQLager -> SQLite library
51. SQLiter/SQLager . DatabaseInstance.
52. SQLiter/SQLager
53. Multiplatform settings SharedPreferences on Android and NSUserDefaults on iOS.
54. Multiplatform settings
55. Multiplatform settings
56. kotlinx.serialization
57. Considerations in state An object belongs to one thread
58. Considerations in state Frozen objects can be shared by threads
59. Concurrency - frozen objects Everything you have written until now is not frozen
60. Considerations in state Runtime safety: Kotlin/Native can verify safe mutability
61. Considerations in state - Generics
62. Considerations in state - Generics
63. Considerations in state - Generics
64. Considerations in state
65. Considerations in state iOS devs?
66. 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 ”
67. The future
68. Flutter vs Kotlin/Native? Flutter - custom UI Widgets Kotlin - more performant Kotlin - better ecosystem
69. Recommendations - Use it with caution - Shared components - Keep versioning in mind - Do not compromise 100% of a project
70. 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)