Java-interop is bleeding:

> Task :Examples:ExampleApplication:processDebugAnnotationsWithJavac FAILED
error: cannot access JvmStatic
  class file for kotlin.jvm.JvmStatic not found
  Consult the following stack trace for details.
  com.sun.tools.javac.code.Symbol$CompletionFailure: class file for kotlin.jvm.JvmStatic not found
1 error

When compiling Java referencing a Kotlin library, is it expected that the annotation processor requires Kotlin annotations to be defined?

Is there any other idiomatic way to do this?

return when {
        pojo.dog != null -> {
            mapDog(this, pojo = pojo.dog!!)
        }
        <http://pojo.cat|pojo.cat> != null -> {
            mapCat(this, pojo = <http://pojo.cat|pojo.cat>!!)
        }
        else -> {
            mapDefault(this)
        }
    }

I have to add the

!!

because otherwise is saying

Smart cast is impossible because pojo.cat is an API class that is on a different module

How expensive are coroutines? 🤔 I mean, what might go wrong if I do something like this?

Hi, How to get reified type parameter nested? I means

inline fun <reified T: Any> awsl()

If I use it as:

awsl<List<String>>()

How to get the

String

from

T

? Thank you

how will i run kotlinc command by using gradle-kotlin plugin

Are there ways to restrict the scope of a particular extension function to where

this

is not the receiver? For instance, if I’m wrapping an existing API in a DSL, a

fun String.bar()

might behave differently depending on what

this

is. I’m not able to subclass the wrapped API data type as it’s final, and inline classes don’t provide delegates apparently. I thought this would work:

class Foo {
  fun doSomething(it: String) {
    // TODO
  }
}

inline class Bar(val foo: Foo) {
  fun String.doSomething() = doSomething(this)
}

But

Bar(Foo()).doSomething("hello")

is undefined.

Just wanted to share something that really impressed me about Kotlin having only worked with the language a few days: I was told to add a semi-complex date sort to an array of event objects, where events that have not happened yet are first, in ascending order. Then, events that are currently happening, followed by events that have already happened. Started to write a write a really janky lambda custom comparator, but then I found out you can just do this:

val sortedGames = games.sortedWith(compareBy{
    Instant.now().compareTo(it.dateTime)
})

noob here - why don't these match?

well i have a kotlin project and it uses gradle-kotlin plugin the thing it uses this plugin to run / configure kotlin not sure what is the equivalent of kotlinc via this as CI fails to run

kotlinc

command

is there a method in List that allows me to do that easily? Thanks

Hi, i have some problem with generic types. Maybe someone can help me out. Consider the following code

class MyClass<T : Comparable<T>> {
    fun join(other : MyClass<T>) {
        // so some stuff
    }
}

fun someFunction(a : Any, b : Any) {
    val instanceA = a as MyClass<*>
    val instanceB = b as MyClass<*>

    instanceA.join(instanceB)
}

is there a formatting convention for where to put the companion object inside a class?

want to contribute to kotlin projects please let me know right channel for this.

Anyone faced this issue, where api response is not static but dynamic, like in case of 200 it will give full json response body and in case of 304 empty body and then there moshi throws exception. If anyone dealt with it before, I know we can write convertor but is there any other way.

Hi, I have a problem. IDE tell me my lambda 's parameter type is wrong. But the expected type is same as I wrote... I don't know what's wrong with me...

In my calc, the type I wrote is correct... Same as IDE & compiler 's expected. I try to enable/disable the new type inference algorithm, but useless...

When extension functions are used in Java, they're represented as the method name taking the receiver as a parameter. How can I specify the name of this parameter in Java? Currently it shows up in IntelliJ as

$this$methodName

How does one create default implementations of interface methods like in Java, but with Kotlin? For example:

interface Example {

default public void method(){

println("how default method implementations look in java, using the keyword default"

}

(Simple?) question? I want to create a generic subclass of RecyclerView.Adapter<RecyclerView.ViewHolder>. I tried:

class FungibleRecyclerAdapter<T : RecyclerView.ViewHolder>():RecyclerView.Adapter<RecyclerView.ViewHolder>() {
   override fun onCreateViewHolder(parent:ViewGroup, viewType:Int):T {
      return RecyclerView.ViewHolder()
   }

   override fun getItemCount():Int {
      return 1
   }

   override fun onBindViewHolder(holder:T, position:Int) {
   }
}

I got a couple of errors: 1. It complains that FungibleRecyclerAdatper is not a proper subclass because it doesn’t implement all of the methods it should 2. It complains that it does not know what the return ViewHolder() is not what it wants, a T 3. It complains that the onBindViewHolder doesn’t override any method I can make a “normal” subclass of the Adapter where I specify a specific subclass of RecyclerView.ViewHolder if I want:

MyAdapter() : RecyclerView.Adapter<MyRowViewClass>() { … }

where

MyRowViewClass

is a subclass of

ViewHolder

just fine. But I wanted to make a generically pluggable one.

FWIW, the document on generics didn’t help at all. It’s all about how Java did it wrong. I’m coming to Kotlin from the Swift world and don’t care about Java.

I'm trying to provide a default implementation for a Java interface, It contains one value, with a getter and a setter. (isCancelled() & setCancelled(boolean)) When i try to implement this in Kotlin, it does not allow me to convert this into a property, when I add another property for this, it will generate additional getters and setters

Hi to all! Who has read any of these books and which one do you recommend. (I’m not into Android) https://kotlinlang.org/docs/books.html

Is StateFlow/EventFlow as talked about in a KotlinConf talk by @elizarov implemented? If yes, is it stable?

Just curious if anyone from the JB team can shed light on why IntelliJ default auto-format for code in kotlin is different than the Kotlin code style guidelines from JB? I know there is an article that talks about the differences, but I'm more curious why JB doesn't just align them?

This message was deleted.

why doesnt

List

inherit from

Set

? isn't a Set the same thing as a List but without indexing?

Does anyone can help? I’ve published a mpp library to bintray, gradle finds it but does not resolve the package in base module. But if i append -jvm to the module it resolves the package.

How would you copy the whole content of class A to class B data class A(val name:String, val list:List<A>) to data class B(val name:String, val list:List<B>)

Hello everyone, I’ve got kind of a noob question: how do you properly log (or just print) inside a test? specifially if it runs with gradle?

Hi guys, I'm wondering if the

?.

operator thread safe? for example I have a

var str: String? = null

, is it safe to call

str?.length

? could NPE happen?