What's New In Kotlin at Google IO 2019 - Summary

Transcript

1. What’s New in Kotlin Google I/O 2019

2. Back To The Future: 2017 2017 Keynote → Google announces

   official Kotlin support Creation of Foundation: - Lead Language Designer - Control breaking changes via Language Committee

3. State Of Kotlin 2019 ➔ Preferred language by Google for

   Android dev ➔ Best support in Jetpack libraries ◆ KTX, Jetpack Compose, etc. ➔ Used at Google ◆ Drive, Nest, Home, system UI, etc. ➔ Koltin/Native → Now Beta! ➔ Coroutines everywhere

4. Capturing ‘when’ val response = getResponse() when (response) { OK

   -> process(response) CANCELED -> print("canceled") }

5. Capturing ‘when’ when (val response = getResponse()) { OK ->

   process(response) CANCELED -> print("canceled") }

6. Experimental Annotation @Experimental(level = WARNING) annotation class NewAPI @NewAPI class

   MyService val service = MyService()

7. Contracts fun MyClass?.notNull(): Boolean { contract { returns(true) implies(this@notNull !=

   null) } return this != null }

8. Serializable Annotation @Serializable data class Customer( val id: Int, val

   name: String ) Json.stringify(Customer.serializer(), customer)

9. Flow → Asynchronous cold streams, in preview! val values: Flow<Int>

   = flow { delay(1000) emit(42) } values.collect { value -> println("Received $value") }

10. More Language Features! ➔ Unsigned Ints ➔ Better parallel builds

    with Gradle ➔ Incremental Annotation Processor with KAPT ➔ New Type Inference Engine (helps with Rx!) ➔ Progressive Mode (more experimental features)

11. Better Community Support ➔ Code Samples in Kotlin ➔ New

    Online Training w/ Udacity
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