Envelope<T>

*

method_missing

__call__

MyClass().unknownMethod()

Dynamic

Extension functions should not use variables from a scope other than the scope available to them from the class they’re extending. Instead, variables should be passed in as parameters. Put another way, extension functions should be “stateless”, and not rely on where they’re defined to function. Extension functions should be able to be moved to a new file and continue to work.

hasNext()

while

public static void printEachForward(BreakIterator boundary, String source) {
     int start = boundary.first();
     for (int end = boundary.next();
          end != BreakIterator.DONE;
          start = end, end = boundary.next()) {
          System.out.println(source.substring(start,end));
     }
 }

returnFromInline { return }
    inline fun returnFromInline(ret: () -> Unit) {
            ret()
    }

returnFromInline()
    inline fun returnFromInline() {
            return
    }

class BehaviorRelayUpdateOnlyProperty<T>(relay: BehaviorRelay<T>) : BehaviorRelayProperty<T>(relay)

constructor(mutablePropertyRelay: BehaviorRelay<MutableCollection<*>>) : this(mutablePropertyRelay)

fun bar(): Single<List<Number>> {
    return Single.just(listOf<Int>())
}

type mismatch

fun bar(): Single<List<Number>> {
    val foo = Single.just(listOf<Int>())
    return foo
}

Single

fun bar(): Single<List<Number>> {
    val foo = Single.just<List<Number>>(listOf<Int>())
    return foo
}

?.

!!

fuel http client

{Origin=[abc], Content-Type=[application/json]

{Origin=abc, Content-Type=application/json

String!

interface MyInterface: T where T : SomeType

lazy

val Foo.bar by lazy { this.baz }

this

Foo

fun test1() {
    println("1")
    printId()
    thread {
        println("2")
        printId()
        throw IllegalStateException("an exception")
    }.join()
    println("3")
}


fun printId(){
    println("Thread ID: $id")
}

val id get() = Thread.currentThread().id

1
Thread ID: 1
2
Thread ID: 11
Exception in thread "Thread-0" java.lang.IllegalStateException: an exception
	at com.github.andrewgazelka.kotlintest.ThreadExceptionTestKt$test1$1.invoke(ThreadExceptionTest.kt:12)
	at com.github.andrewgazelka.kotlintest.ThreadExceptionTestKt$test1$1.invoke(ThreadExceptionTest.kt)
	at kotlin.concurrent.ThreadsKt$thread$thread$1.run(Thread.kt:30)
3

Thread-0

var harvest : HashMap<String,Int> = HashMap()
harvest[plant.name] += amount