Kotlin in Production

Transcript

1. Kotlin in Production
2. @goncalossilva j.mp/kotlininproduction
4. Java?
5. Alternatives?
6. 1 Modern
7. 1 Modern 2 Fast
8. 1 Modern 2 Fast 3 Small
9. 1 Modern 2 Fast 3 Small 4 Interoperable
10. Scala
11. 1 Modern Scala
12. 1 Modern 2 Fast Scala
13. 1 Modern 2 Fast 3 Small Scala
14. 1 Modern 2 Fast 3 Small 4 Interoperable Scala
15. Clojure
16. 1 Modern Clojure
17. 1 Modern 2 Fast Clojure
18. 1 Modern 2 Fast 3 Small Clojure
19. 1 Modern 2 Fast 3 Small 4 Interoperable Clojure
20. Groovy
21. 1 Modern Groovy
22. 1 Modern 2 Fast Groovy
23. 1 Modern 2 Fast 3 Small Groovy
24. 1 Modern 2 Fast 3 Small 4 Interoperable Groovy
25. Swift
26. Swift Modern Fast Small Interoperable
27. Java 10
28. Java 10 Modern Fast Small Interoperable
29. Kotlin
30. 1 Modern 2 Fast 3 Small 4 Interoperable Kotlin
31. class Purchase constructor(value: Int, success: Boolean) { val value = value val success = success }
32. class Purchase(val value: Int, val success: Boolean)
33. data class Purchase(val value: Int, val success: Boolean)
34. data class Customer(val name: String, val purchases: List<Purchase>) data class Purchase(val value: Int, val success: Boolean)
35. data class Customer(val name: String, val purchases: List<Purchase>) data class Purchase(val value: Int, val success: Boolean) object Dataset { val customers: MutableList<Customer> = ArrayList() init { customers.add(Customer( "Gonçalo”, arrayListOf(Purchase(42, true), Purchase(9000, false)))) } }
36. fun successfulPurchases(name: String) : List<Purchase> { val successfulPurchases: MutableList<Purchase> = ArrayList() var customer: Customer? = null for (c in Dataset.customers) { if (c.name == name) { customer = c break } } if (customer != null) { for (purchase in customer.purchases) { if (purchase.success) successfulPurchases.add(purchase) } } return successfulPurchases }
37. fun successfulPurchases(name: String) : List<Purchase> { val successfulPurchases: MutableList<Purchase> = ArrayList() var customer: Customer? = null for (c in Dataset.customers) { if (c.name == name) { customer = c break } } if (customer != null) { for (purchase in customer.purchases) { if (purchase.success) successfulPurchases.add(purchase) } } return successfulPurchases }
38. fun successfulPurchases(name: String) : List<Purchase> { val successfulPurchases: MutableList<Purchase> = ArrayList() var customer: Customer? = null for (c in Dataset.customers) { if (c.name == name) { customer = c break } } if (customer != null) { for (purchase in customer.purchases) { if (purchase.success) successfulPurchases.add(purchase) } } return successfulPurchases }
39. fun successfulPurchases(name: String) : List<Purchase> { val successfulPurchases: MutableList<Purchase> = ArrayList() var customer: Customer? = null for (c in Dataset.customers) { if (c.name == name) { customer = c break } } if (customer != null) { for (purchase in customer.purchases) { if (purchase.success) successfulPurchases.add(purchase) } } return successfulPurchases }
40. fun successfulPurchases(name: String) : List<Purchase> { val successfulPurchases: MutableList<Purchase> = ArrayList() var customer: Customer? = null for (c in Dataset.customers) { if (c.name == name) { customer = c break } } if (customer != null) { for (purchase in customer.purchases) { if (purchase.success) successfulPurchases.add(purchase) } } return successfulPurchases }
41. fun successfulPurchases(name: String) : List<Purchase> { val successfulPurchases: MutableList<Purchase> = ArrayList() var customer: Customer? = null for (c in Dataset.customers) { if (c.name == name) { customer = c break } } if (customer != null) { for (purchase in customer.purchases) { if (purchase.success) successfulPurchases.add(purchase) } } return successfulPurchases }
42. fun successfulPurchases(name: String) : List<Purchase> { val successfulPurchases: MutableList<Purchase> = ArrayList() // Find the customer. val customer = Dataset.customers.find { it.name == name } // Gather successful purchases. if (customer != null) { successfulPurchases.addAll(customer.purchases.filter { it.success }) } return successfulPurchases }
43. fun successfulPurchases(name: String) : List<Purchase> { return Dataset.customers.find { it.name == name }?.purchases? .filter { it.success } ?: emptyList() }
44. fun successfulPurchases(name: String) : List<Purchase> { return Dataset.customers.find { it.name == name }?.purchases? .filter { it.success } ?: emptyList() }
45. fun successfulPurchases(name: String) : List<Purchase> { return Dataset.customers.find { it.name == name }?.purchases? .filter { it.success } ?: emptyList() }
46. fun successfulPurchases(name: String) : List<Purchase> { return Dataset.customers.find { it.name == name }?.purchases? .filter { it.success } ?: emptyList() }
47. fun successfulPurchases(name: String) : List<Purchase> = Dataset.customers.find { it.name == name }?.purchases? .filter { it.success } ?: emptyList()
48. fun successfulPurchases(name: String) : List<Purchase>? = Dataset.customers.find { it.name == name }?.purchases?.filter { it.success }
49. fun Customer.successfulPurchases() : List<Purchase> = purchases.filter { it.success } customer.successfulPurchases() // Works!
50. fun successfulPurchases(name: String) : List<Purchase> { val successfulPurchases: MutableList<Purchase> = ArrayList() var customer: Customer? = null for (c in Dataset.customers) { if (c.name == name) { customer = c break } } if (customer != null) { for (purchase in customer.purchases) { if (purchase.success) successfulPurchases.add(purchase) } } return successfulPurchases }
51. fun successfulPurchases(name: String) : List<Purchase> = Dataset.customers.find { it.name == name }?.purchases? .filter { it.success } ?: emptyList()
52. Higher-order functions, properties, mixins and delegation, extension functions, static nullability checking, automatic casts, reified generics, declaration-site variance, modules and build infrastructure, inline functions, operator overloading, String interpolation, pattern matching, first class IDE support, Java converter, default parameters, infix methods, destructuring declarations, and more...
53. Modern 2 Fast 3 Small 4 Interoperable Kotlin
54. Statically typed byte code Inlined lambdas github.com/JetBrains/kotlin-benchmarks Kotlin
55. Modern Fast 3 Small 4 Interoperable Kotlin
56. 5k methods 1MB Smaller and smaller Kotlin
57. Modern Fast Small 4 Interoperable Kotlin
58. 100% interoperable Idiomatic Kotlin with idiomatic Java Annotations for customization Kotlin
59. Modern Fast Small Interoperable Kotlin
60. Modern Fast Small Interoperable Kotlin 5 Android APIs
61. db.beginTransaction() try { db.delete("hackathon", "name = ?", arrayOf("Pixels Camp")) db.setTransactionSuccessful() } finally { db.endTransaction() }
62. inline fun SQLiteDatabase.inTransaction(func: SQLiteDatabase.() -> Unit) { beginTransaction() try { func() setTransactionSuccessful() } finally { endTransaction() } } db.inTransaction { delete("hackathon", "name = ?", arrayOf("Pixels Camp")) }
63. inline fun SQLiteDatabase.inTransaction(func: SQLiteDatabase.() -> Unit) { beginTransaction() try { func() setTransactionSuccessful() } finally { endTransaction() } } db.inTransaction { delete("hackathon", "name = ?", arrayOf("Pixels Camp")) }
64. inline fun SQLiteDatabase.inTransaction(func: SQLiteDatabase.() -> Unit) { beginTransaction() try { func() setTransactionSuccessful() } finally { endTransaction() } } db.inTransaction { delete("hackathon", "name = ?", arrayOf("Pixels Camp")) }
65. inline fun SQLiteDatabase.inTransaction(func: SQLiteDatabase.() -> Unit) { beginTransaction() try { func() setTransactionSuccessful() } finally { endTransaction() } } db.inTransaction { delete("hackathon", "name = ?", arrayOf("Pixels Camp")) }
66. fun Cursor.getStringOrNull(columnName: String): String? { val index = getColumnIndexOrThrow(columnName) return if (isNull(index)) null else getString(index) } fun View.setPaddingTop(top: Int) { setPadding(paddingLeft, top, paddingRight, paddingBottom) } fun View.toBitmap() : Bitmap? { if (width > 0 && height > 0) { val bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888) val canvas = Canvas(bitmap) draw(canvas) return bitmap } else { return null } }
67. fun Cursor.getStringOrNull(columnName: String): String? { val index = getColumnIndexOrThrow(columnName) return if (isNull(index)) null else getString(index) } fun View.setPaddingTop(top: Int) { setPadding(paddingLeft, top, paddingRight, paddingBottom) } fun View.toBitmap() : Bitmap? { if (width > 0 && height > 0) { val bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888) val canvas = Canvas(bitmap) draw(canvas) return bitmap } else { return null } }
68. fun Cursor.getStringOrNull(columnName: String): String? { val index = getColumnIndexOrThrow(columnName) return if (isNull(index)) null else getString(index) } fun View.setPaddingTop(top: Int) { setPadding(paddingLeft, top, paddingRight, paddingBottom) } fun View.toBitmap() : Bitmap? { if (width > 0 && height > 0) { val bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888) val canvas = Canvas(bitmap) draw(canvas) return bitmap } else { return null } }
69. fun Cursor.getStringOrNull(columnName: String): String? { val index = getColumnIndexOrThrow(columnName) return if (isNull(index)) null else getString(index) } fun View.setPaddingTop(top: Int) { setPadding(paddingLeft, top, paddingRight, paddingBottom) } fun View.toBitmap() : Bitmap? { if (width > 0 && height > 0) { val bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888) val canvas = Canvas(bitmap) draw(canvas) return bitmap } else { return null } }
70. fun Cursor.getStringOrNull(columnName: String): String? { val index = getColumnIndexOrThrow(columnName) return if (isNull(index)) null else getString(index) } fun View.setPaddingTop(top: Int) { setPadding(paddingLeft, top, paddingRight, paddingBottom) } fun View.toBitmap() : Bitmap? { if (width > 0 && height > 0) { val bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888) val canvas = Canvas(bitmap) draw(canvas) return bitmap } else { return null } }
71. Modern Fast Small Interoperable Kotlin Android APIs
72. Supported?
74. Beyond Android & JVM
75. Kotlin Koans https://kotlinlang.org/docs/tutorials/koans.html Kotlin and Android https://developer.android.com/kotlin/index.html Kotlin Slack http://slack.kotlinlang.org/ Resources
76. @goncalossilva j.mp/kotlininproduction Thank you