Hi team, I have a Kotlin JVM project that depends on

org.jetbrains.kotlin:kotlin-compiler-embeddable:jar:1.4.30:compile

, which introduces the JetBrains trove4j fork

org.jetbrains.intellij.deps:trove4j:jar:1.0.20181211:runtime

as a transitive dependency. (entire dependency tree in thread). One of the usage scenarios installs the jars and transitive dependencies into a program that already has GNU

trove4j

as a dependency, but in an incompatible version. What is the best way to avoid dependency clashes here? I tried shading all of

kotlin-compiler-embeddable

and the jetbrains

trove4j

into the jar that I generate for installation and it works. Is this the recommended way to solve this clash between jetbrains

trove4j

fork and GNUE

trove4j

? If anyone has examples, I would like to take a look at those to make sure, I only include the dependencies necessary and also don't leave out anything.

Does anyone want to code with me? I am looking to test the new 'code with me' feature on IntelliJ 2021.

enum class PacketType(val id: Short, vararg aliases: String) {
    CUSTOM_PAYLOAD(0), KEEP_ALIVE(1), LATENCY(2);

    companion object {
        private val PACKETS_BY_ID = mutableMapOf<Short, PacketType>()
        private val PACKETS_BY_ALIAS = mutableMapOf<String, PacketType>()

        fun fromId(id: Short): PacketType? = PACKETS_BY_ID[id]
        fun fromName(id: String): PacketType? {
            return try {
                valueOf(id)
            } catch (e: IllegalArgumentException) {
                PACKETS_BY_ALIAS[id]
            }
        }
    }

    init {
        PacketType.PACKETS_BY_ID[id] = this
        for (alias in aliases) {
            PacketType.PACKETS_BY_ALIAS[alias] = this
        }
    }

    operator fun get(id: Short) = fromId(id)
    operator fun get(id: String) = fromName(id)
}

For some reason, PACKETS_BY_ID and PACKETS_BY_ALIAS don't get initialized

Ok this might be a little dumb question but here we go I'm creating an extension property on

androidx.compose.material.Colors

class which should be changed later that's why I have used

var

var Colors.warning: Color
    get() = Color(0xFFFFC107)
    set(value) {
        field = value
    }

But I'm getting error in the setter

Unresolved reference: field

Dunno how to handle this scenario

import kotlin.jvm.internal.Reflection

inline fun <reified T: Number>round(number: T): Int {
    return when(T::class){
        Int::class -> number as Int
        Double::class -> (number as Double).toInt()
        else -> throw IllegalArgumentException("Invalid type")
    }
}

fun test(){
    print(round(1))
    print(round(2.0))
    print(round(3f))
}

fun howShouldBeCompiled(){
    print(1)
    print((2.0 as Number).toInt())
    throw IllegalArgumentException("Invalid type")
}

fun howItIsCompiled() {
    val number = 1
    val type = Reflection.getOrCreateKotlinClass(Int::class.java)
    var result1: Int = when(type){
        Int::class.java -> number
        Double::class.java -> (number as Double).toInt()
        else -> throw java.lang.IllegalArgumentException("Invalid type")
    }
    print(result1)
    
    //... do the same for each case
}

Is there a way to inline reified generic functions at compile time? Isn't T::class known at compile time? The only alternative which I see is removing the generic and manually overload each possible accepted class (in this case it's just two, but I have more complex cases with like 8 input classes). I feel like having only one function declaration with a switch (when) is more elegant than 8 declarations with overload (for simple functions).

it seems default parameters for generic types need a space before the equals sign. is this a bug or is it documented somewhere?

The following construct confuses me.

interface Scope

class Service : Scope {

    fun <T> scoped(block: Service.() -> T): T {
        return block().also {
            finalize()
        }
    }

    fun Scope.foo(): String {
        return "Heya!"
    }

    private fun finalize() {
        // release resources and stuff
    }

}

fun main() {

    val service = Service()

    val res = service.scoped {
        foo()
    }

    service.foo() // ERROR
}

Basically I achieved what I wanted - to be able to call Service's methods only within a scope, so some finalization work can be done automatically, instead of relying on the consumer to do it. However I don't really understand why I can't call

foo

outside the scope. Can anyone explain it, please?

Is it possible to use reflection to get extension functions for

String

such as

toInt

toLong

etc?. I can see the file and package they are contained in here but i am not sure how to actually access them, could anyone provide a hint?

Hello. I noticed that if I try to create a new object of an inner class with a null safe call I get an exception but if I do that using the

let()

function it works fine even though the IDE is complaining about it. Is this intended behavior?

Hi, I'm looking for an Android Engineer with a strong background in Kotlin. Is this the best place to post a job, or is there a more appropriate channel for that?

I'm trying to call get() on a property via reflection. I pass an instance of the class in question to get() and I get the error

Type mismatch: inferred type is MessageDispatch but Nothing was expected

what's a

nothing

? And the docs say it should be an instance of the class... which it is.. very confused.

does Kotlin have some sort of conditional compilation? i have some code (scattered around) that would like to have present while developing, but not be there in final releases, is there a way to do that?

🆘 Require knowledge from all the Kotlin Gurus. I was looking into a JavaScript code and found the following syntax

const {a , …remaining} = user

…

 is called spread operator in JavaScript Where

user = {a : "12", b : 2 , c: "Some random String"}

so the value of 

user.a

 was copied in variable 

a

 and all the remaining keys of user object 

user.b

 and 

user.c

 were copied in 

remaining

 variable. This concept is called 

Destructuring

  and in kotlin world, the nearest possible syntax that I know, is

val (a,b,c) = user

But, can we write this anyway better without declaring 3 variables ??? So, that my final code should be

val (a,remaining) = user

how can I flip a boolean state in a given interval (every 2 min)?

Hello everyone! Could please anyone point me to a detailed documentation on how to use Kapt server side, possibly with maven? I found a lot of articles but they are all Android oriented....

I have a KMM project with Sealed classes and classes inside of those, to represent some state. On the Kotlin side it's idiomatic to use a "when" statement on these. On the swift side the best I could come up with were switch statements and it doesn't seem to realize that my cases are exhaustive and instead requires me to add a "default:" case. Is this a limitation of the what KMM sealed classes compile down to in their Swift interop? let menuStyle = projectConfig.settings.appearance.menuStyle       switch menuStyle {       case (is Settings.AppearanceMenuStyleBottom):         print("Bottom Menu")         break       case (is Settings.AppearanceMenuStyleSlideOut):         print("SlideOut Menu")         break       case (is Settings.AppearanceMenuStyleTiled):         print("Tiled Menu")         break       default: print("Swift requires this even though the sealed class is exhausted")       }

Can you use Java libraries such as LibGDX with Kotlin for game development? I heard there is something called 'libKTX' - can we use 'libKTX' (Kotlin extensions for LibGDX) standalone, or does it need to be combined with LibGDX?

Hey folks. Anyone with experience in proto buffers here?

Hello! My Dependabot just told me that Kotlin

1.4.32

is out, but there are no announcements and no new releases out on GitHub. P.S. Well, basically it said that

serialization

and

multiplatform

plugins are updated to

1.4.32

, seems like the language is not updated yet, but the plugins are.

Is there an easy way to merge two maps of Map<String, Foo> into one map? I know the keys of the two maps are distinct from each other. I.e. I don't want to have Map<String,List<Foo>> as a resulting map.

When using

lateinit var

on the JVM on a field on an object used from more than one thread do you also need

@Volatile

to prevent other threads seeing it as null, or do you get that for free?

What kind of inheritance is this? I see it in Compose docs, but can't find its usage on Kotlin docs. Can a subclass (object) be defined inside the parent class?

I am looking for help with ktor and didn't know which channel was a good channel to go to .. so if someone can direct me to the best channel I would appreciate .

Hello, I can’t compile the following code with Kotlin 1.2.71. However, the code compiled well with Kotlin 1.2.30 even though the same error message shows in my IntelliJ (with red underline).

Restricted suspending functions can only invoke member or extension suspending functions on their restricted coroutine scope

Can I get some advice?

@RestrictsSuspension
abstract class Service() {
    protected suspend inline fun yieldAsync() { ... }
    protected abstract suspend fun start()

    private suspend fun startWrapper() {
        yieldAsync()
        start()
    }

    private fun <T> launchCoroutine(block: suspend () -> T) = block.startCoroutine(...)

    final override fun onLifecycleStart() {
        launchCoroutine { startWrapper() } // <- error spot startWrapper()
    }
}

Hi folks, question about annotation processing. Anyone knows how to read the annotations of the properties in a interface when processing the interface class?

@Model
interface Config {
    @Prop(name = "renamedConfigField")
    val configField: String
}

When processing the Config interface I would like to be able to iterate over it’s properties (which I’m already doing) but I’m not being able to read the fields annotations (e.g. read the @Prop annotation on the

configField

)

I had the same doubt. Where or how could this be useful? Would anyone here know how to give a tip? This is the tweet: https://twitter.com/pablisc0/status/1374468084916908041

Hi all, I have a question about extension functions, I'm kind of stuck. Hope anyone can point me in the right direction. The problem I'm trying to solve: I want to be able to check when a property in a data class has been set. The goal is to be able to differentiate between a null value (the property has been set to null) and a non present (value was not set). A potential use case is to implement a HTTP Patch where you receive Input Objects as DTO and you want to save in the database entities only the properties set in the DTO. My initial approach: I thought it could be solve with a delegate using a map, so I could use the map to check if the value was actually set. Here is some code, but it is not working.

class InputExample(val map: Map<String, Any?>) {
        val name: String? by map
        val age: Int?     by map
        val lastname: String? by map

        fun KProperty<Any>.isPresent(): Boolean {
            //return map.containsKey(this.name)
            return true
        }
 }

I was trying to get to a interface like this:

inputType.lastname.isPresent()

Hi there, my team is new to kmm, have a question about publishing a kmm framework from ios side. if we want to track the uncaught exception trace of kotlin, do we have to publish a debug framework instead of a release one? （we have read issues and docuement about this, not so sure） https://github.com/JetBrains/kotlin-native/issues/2600 https://kotlinlang.org/docs/native-ios-symbolication.html

best linter available for kotlin with gradle / intellij support?