Hey, is there a way to call an extension method with appropriate namespace, as you would with a static method? Basically to deal with name conflicts?

I've got a

BehaviorSubject<Int?>

, but IntelliJ is insisting that I have to pass an Int to onNext

hmm, through some serialization shenanigans, I've got an instance

t

of something thats declared as

object  Thingy

, that is not equal to

Thingy.INSTANCE

. I could update all my when statements to use

when(it) { is Thingy ->

rather than

when(it) { Thingy ->

, but that seems cryptic.

but what I'd really like is to direct kotlin to just insert a

readResolve

method on all things declared as

object

.

Hi all, I'm having a hard time with gson because of it's use of Unsafe that leads to non-nullable variables getting null as value. Can somebody recommend me a JSON serializer library that works properly with Kotlin

Hello! This - https://gist.github.com/andredasilvapinto/a63468acd56498fd6f17bcad2905d41b - compiles but when I run it produces a

java.lang.VerifyError: Bad type on operand stack

(full error on the gist comment). Why is that?

Out of the results of:

"0101-1002-0909-0210-1115-1511".split("-")
            .flatMap { it.chunked(2).map { it.toInt() } }
        	.map { if (it > 9) (it + 55).toChar() else (it + 48).toChar() }
        	.chunked(2)

I need:

11:A2:99:2A:BF:FB

, how could I do that idiomatically, also, is there a simpler algo for this? It's converting to hex..

Hi all! I'm creating a web-application with Kotlin/JS. I want the generated .js files to be automatically copied into a directory whenever the modules successfully builds. Is there a clean and easy way? Couldn't find such a feature in IntelliJ, is it easier to create a bash script to copy the files whenever they change?

do any one have pdf copy of kotlin in action ?

Does someone know how I can bring nullable in the following parameter in terms of a type parameter

class A<T>(val a: B<T>.()->Unit)

I tried:

class A<T1, T2: (B<T>.()->Unit)? >(val a: T2)

But that failes stating that an extension function type cannot be used as upper bound. I want to be able to have the parameter nullable in some places and not nullable in others without creating two classes for it

hello guys, any one is using kotlin with a web framework beside spring?

have you ever seen Kotlin code throw:

java.lang.IncompatibleClassChangeError: Implementing class

	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    ...

Hi guys! I have something like this:

interface Base {
    fun print()

    fun getValue() : String
}

class BaseImpl : Base {

    override fun print() { print(getValue()) }

    override fun getValue(): String {
        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
    }
}

class Derived(private val b: Base) : Base by b {
    override fun getValue(): String = "hello"
}

fun main(args: Array<String>) {
    val b = BaseImpl()
    Derived(b).print() // prints 10
}

obviously the output is

Exception in thread "main" kotlin.NotImplementedError: An operation is not implemented: not implemented
	at BaseImpl.getValue(Main.kt:12)
	at BaseImpl.print(Main.kt:9)
	at Derived.print(Main.kt)
	at Main3Kt.main(Main.kt:22)

which is the cleanest way to refactor this snippet to specify in

Derived

what should be used in

BaseImpl.print()

?

val f1 = { it.length == 3}   // T.() -> Boolean
val f2 = { length == 3} .    // (T) -> Boolean

this does not look the same to me

Everyone else just replacing a single letter. Surprised it wasn't KSON for example.

is there any way to get a hold of a

Map

entry without iterating over the whole entry set? I need it to be able to change the associated value of a key repeatedly without having to find the key in the map again every time.

I’m wondering. Kotlin doesn’t allow you to call methods with generics with specifying the type - which is one of the few situations where I’m forced to write more code than with Java. e.g.

val example = listOf()

won’t compile, I must write

val example = listOf<Any>()

see examples: https://kotlinlang.slack.com/archives/C0922A726/p1514989124000312?thread_ts=1514986352.000228&cid=C0922A726 https://kotlinlang.slack.com/archives/C0922A726/p1514987282000262?thread_ts=1514986352.000228&cid=C0922A726 Why is this forced? I’ve Googled but can’t find discussion on it

Hi there! What is the best channel here to ask about building DSLs?

is it possible to have generics that need to fulfill one upper bound or the other? With where clauses you can only specify multiple upper bounds that all need to be fulfilled at the same time

i get

kotlin/reflect/jvm/internal/KotlinReflectionInternalError

when running the app from jar, but the app works from intellij

I thought that exceptions have to be thrown. In my case I have a test and when I create an exception it is thrown automatically and I don’t understand, why:

class RuntimeExceptionMapperTest :  StringSpec() {
    init {
        val mapper = RuntimeExceptionMapper()
        "ConcurrentModificationException should be mapped to CONFLICT (409)" {
            val e = ConcurrentModificationException("Test") // throws exception - why?
            mapper.toResponse(e).status shouldBe CONFLICT.statusCode
        }
    }
}

I use Kotlin 1.2.10 with KotlinTest 2.0.7 and have no idea, why the exception is thrown. I just want to create an exception object, not throwing it…

is there a way i can use the

class

of my generic? my construct looks like this:

abstract class Base<T: Parent> {
 val something: MyGenericClass<T>(T::class.java)
}

but it says i cant use

T

as reified type parameter and should use a class instead.

Why in this code type

GT

cannot be inferred?

class A<T>(val t: T)
class B<T, out U: A<T>>(val t: T, val at: U)

fun <T> B<T, *>.withCapturedU(): B<T, A<T>> = this

private fun <FT> f(x: B<FT, *>) {
  g(x) // ERROR, why?
  g(x.withCapturedU()) // OK
}

private fun <GT>  g(y: B<GT, A<GT>>) {
  println(y)
}

This is obviously a regression (I filed a ticket but just curious if somebody else saw that too)

Gradle 4.4 or newer, sourceCompatibility = JavaVersion.VERSION_1_9; targetCompatibility = JavaVersion.VERSION_1_9

guys, which one lib is more mature:

exposed

or

squash

? it seems both serve for same purpose

things I miss in Kotlin (compared to Scala): type members value types things I miss in Scala (compared in Kotlin): null operators and smart cast extension functions inline methods I wish the two language can be combined...

does anyone actually use Kotlin DSL for HTML [https://github.com/Kotlin/kotlinx.html]

Anyone know how to fix

Cannot access 'clazz': it is private/*private to this*/ in 'Test'

?

class Test<out T>(private val clazz: Class<@UnsafeVariance T>) {
    companion object {
        fun test(test: Test<*>) = test.clazz
    }
}

Making

clazz

public or making

T

invariant fixes the error but I'd prefer to avoid that. Companion objects should have access to private members so this should work as is.

Is that conceptually a good use of a data class? I’ve written them with methods in them but typically limit the methods to adding extra meaning to the data like isExpired or fullName methods/properties.