Kotlin For Swift Developers - CocoaHeads NL, Amsterdam, March 2018

Video from this version of the presentation:
https://www.youtube.com/watch?v=Tzgh4OTWv4c

Kotlin is a new language born on the JVM that's gained a ton of popularity with Android developers. Learn about its similarities and differences with swift, and a bit about where it's going in the future (though it's not quiiiiite there yet).

Now with actual links to some books I've been working on!

Transcript

1. KOTLIN FOR SWIFT DEVELOPERS COCOAHEADS NL | AMSTERDAM | MARCH 2018 @DESIGNATEDNERD | BAKKENBAECK.COM | JUSTHUM.COM
2. !"
10. ✨ " ☕ $ ✨
12. WHAT IS KOTLIN ?
17. WHY SHOULD I CARE?
20. A CONSTANT STRING
21. SWIFT let greeting = "Hello World"
22. SWIFT let greeting = "Hello World" KOTLIN val greeting = "Hello World"
23. AN OPTIONAL INTEGER VARIABLE
24. SWIFT var something: Int?
25. SWIFT var something: Int? KOTLIN var something: Int?
26. ☠ NullPointerException ☠
27. !"
28. GENERICS AND FUNCTIONS AS PARAMETERS
29. SWIFT func useFunction<T, U>(on item: T, function: (T) -> U) -> U { return function(item) } func insertExclamationPoint(in string: String) -> String { return string .components(separatedBy: " ") .joined(separator: "! ") } let result = useFunction(on: "try Swift", function: insertExclamationPoint(in:)) // result: "try! Swift"
30. KOTLIN fun <T, U>T.useFunction(action: (T) -> U): U { return action(this) } fun insertExclamationPoint(in: String) : String { return in.split(" ").joinToString("! ") } val result = "try Kotlin".useFunction { insertExclamationPoint(it) } // result: "try! Kotlin"
31. map filter reduce
32. map filter reduce*
33. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(0, +) // reduced: 6
34. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(0, +) // ! // reduced: 6
35. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(0) { $0 + $1 } // reduced: 6
36. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26
37. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26 KOTLIN val numbers = arrayOf(1, 2, 3) val reduced = numbers.reduce { total, current -> total + current } // reduced: 6
38. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26 ⬆ KOTLIN val numbers = arrayOf(1, 2, 3) val reduced = numbers.reduce { total, current -> total + current } // reduced: 6
39. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26 KOTLIN val numbers = arrayOf(1, 2, 3) val folded = numbers.fold(20) ⬅ { total, current -> total + current } // folded: 26
40. SWIFT let doubled = [ 1, 2, 3 ].map { $0 * 2 }
41. SWIFT let doubled = [ 1, 2, 3 ].map { $0 * 2 } KOTLIN arrayOf(1, 2, 3).map { it * 2 }
44. SWIFT let doubled = [ 1, 2, 3 ].map { $0 * 2 } KOTLIN arrayOf(1, 2, 3).map { it * 2 }
45. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26
46. $0 $1 $2...$∞
47. SWIFT let numbers = [ 1, 2, 3 ] let reduced = numbers.reduce(20) { $0 + $1 } // reduced: 26 KOTLIN val numbers = arrayOf(1, 2, 3) val folded = numbers.fold(20) { total, current -> total + current } // folded: 26 ⬆
49. !"#
51. guard
52. NOW (KOTLIN) optionalThing?.let { it.doSomething() }
53. NOW (WORSE KOTLIN) if (optionalThing != nil) { optionalThing!!.doSomething() }
54. PROPOSED (KOTLIN) guard val thing = optionalThing else { return } thing.doSomething()
55. apply
56. NOW (SWIFT) UserDefaults.standard.set(true, forKey: "DefaultOne") UserDefaults.standard.set(false, forKey: "DefaultTwo)
57. NOW (BETTER SWIFT) let defaults = UserDefaults.standard defaults.set(true, forKey: "DefaultOne") defaults.set(false, forKey: "DefaultTwo)
58. PROPOSED (SWIFT) UserDefaults.standard.apply { "DefaultOne" = true, "DefaultTwo" = false, }
61. KOTLIN / NATIVE
62. LLVM
63. LLVM
64. LLVM
65. SUPPORTED PLATFORMS ▸ x86-64 (macOS, Linux, Windows) ▸ arm64 (iOS, Android) ▸ arm32 (Android) ▸ arm32 hardfp (Raspberry Pi) ▸ WebAssembly (Web)
68. DOCUMENTATION
69. DOCUMENTATION? ¯\_(ϑ)_/¯
70. KOTLIN: ☕ OR " = #
71. try? kotlin
72. https://try.kotlinlang.org
75. EDU TOOLS PLUGIN FOR INTELLIJ OR ANDROID STUDIO
78. OBLIGATORY SUMMARY SLIDE ▸
79. OBLIGATORY SUMMARY SLIDE ▸ Make Friends With Android
80. OBLIGATORY SUMMARY SLIDE ▸ Make Friends With Android ▸ Kotlin Native Is Cool But Not Ready For Production
81. OBLIGATORY SUMMARY SLIDE ▸ Make Friends With Android ▸ Kotlin Native Is Cool But Not Ready For Production try! Kotlin
82. ONE MORE THING
83. ONE MORE THING: (A SHAMELESS PLUG!)
85. BEDANKT, EN TOT ZIENS!
86. LINKS! ▸ Kotlin Home & Documentation: https://kotlinlang.org ▸ KotlinConf iOS App in Kotlin/Native: https://github.com/JetBrains/kotlinconf- app/tree/master/ios ▸ The Edu Tools Plugin for IntelliJ or Android Studio https://kotlinlang.org/docs/tutorials/ edu-tools-learner.html
87. MORE LINKS! ▸ Creating an iOS Framework With Kotlin http://viteinfinite.com/2018/02/creating- an-ios-framework-with-kotlin ▸ RayWenderlich.com Android Avalanche™ https://www.raywenderlich.com/187520/ introducing-the-android-avalanche
88. ILLUSTRATION CREDITS ▸ Monica Komperda, Native Code Forever (Hire her! She's awesome!) http://mokomperda.com/design