Runtime.getRuntime().addShutdownHook(object : Thread() {
	override fun run() {
		server.destroy()
	}
})

apply {…}

kotlinOptions.jvmTarget = "1.8"

Unit

Unit

Nothing?

Visitor<Result, Data>

Unit

Nothing?

Data

class Foo {
    @Suppress("TOPLEVEL_TYPEALIASES_ONLY")
    typealias Bar = String
}

fun main() {
    val hello: Foo.Bar = "hello"

    println(hello)
}

map = mapOf("one" to 1, "two" to "2")

magicWith(map) {

one // 1

two // "2"

}

interface SharedPreferencesBuilder {
    fun build(): SharedPreferences
}

data class Foo(
    val bar: Long? = null
)

select

private final Long

bar

val

var acc = 0
val order = IntArray(a.size) {
    acc += a[it].size
    acc
}

init

data class Node(
	val author: String,
	val message: String,
	val children: List<Node>,
	val parent: Node = this
)

this

fun foo(lastEntry: Entry) {
	val myList = mutableListOf<Entry>()
	var currentEntry = lastEntry
	do {
		myList.add(currentEntry)
		currentEntry = currentEntry.parent
	} while (currentEntry != null)
	myList.reverse()
}

.reverse()

Is there a build in function to shift the contents of a list right or left ?

e.g. list of 1,2,3 would go to 2,3,1 if I shifted right

fun main() {
	runBlocking {
		val tcpSocketBuilder = aSocket(ActorSelectorManager(<http://Dispatchers.IO|Dispatchers.IO>)).tcp()
		val address = InetSocketAddress("127.0.0.1", 2323)

		launch {
			delay(100)
			println("client: connecting to server")
			val socket = tcpSocketBuilder.connect(address)
			println("client: connected")
			println("client: sending data")
			val writer = socket.openWriteChannel()
			writer.writeStringUtf8("hello world\n")
			println("client: data sent")
			println("client: done")
		}

		val serverSocket = tcpSocketBuilder.bind(address)
		println("server: waiting for connection")
		val client = serverSocket.accept()
		println("server: client received")
		val reader = client.openReadChannel()
		println("server: receiving data")
		val message = reader.readUTF8Line(999)
		println("server: data received: $message")
		println("server: done")
	}
}

server: waiting for connection
client: connecting to server
server: client received
client: connected
client: sending data
server: receiving data
client: data sent
client: done

"one ".trim()
"two ".trim()
"three ".trim()

run

with

<scope_function> {
  "one ",
  "two ",
  "three ".
}.trim()

Error: The 'java' plugin has been applied, but it is not compatible with the Android plugins

java -jar

when

enum Foo { FOO, BAR, FOOBAR }

val foo = ...
when(foo) {
  FOO -> sayFoo()
  BAR -> sayBar()
  FOOBAR -> do nothing
}

interface Id

inline class BarId(val value: Int): Id
inline class BazId(val value: Int): Id

sealed class Foo<T: Id> {
   abstract val id: T
   data class Bar(...): Foo<BarId>()
   data class Baz(...): Foo<BazId>()
}

fun <T: Foo<U>, U: Id> myFun(entity: T): U = TODO()

Foo

myBar.changeId

BarId

Bar

sealed class Foo<T: Id> {
   ...
   abstract fun <T: Foo<U>, U: Id> changeId(id: U): T
}

data class Bar(...): Foo<BarId>() {
   override fun changeId(id: BarId): Bar = TODO()
}

changeId

changeId(id: BarId): Bar = this(id=id)