Let's say I have

class A {
  fun B.something() { ... }
}

something()

has two receivers, A and B, yeah? I was hoping that would let me do this:

class B {
  init {
    val a = A()
    a.something()
  }
}

but it seems in reality I have to do this:

class B {
  init {
    val a = A()
    with(a) {
      something()
    }
  }
}

Is there a nicer way to get something closer to the first one?

Hello everybody, I am new here. Excited to start with your all.

Any one official from koltlin community who can answer all my questions

Depends on how you use them - if you

read

one socket and it takes a long time for a message to arrive, the thread is blocked and can't

read

from another socket, even if data is already available there, so the other socket's can experience poor latency. If you do that on multiple threads, or never need to process I/O simultaneously on multiple sockets anyways, this is moot.

Congrats to the 1.4.30 release. I guess its still underway but FYI the corresponding release blog post link on https://kotlinlang.org/releases.html is yet dead.

Will there be an advice from JetBrains about this JCenter situation? Since it will seriously impact the Kotlin Ecosystem… Will there maybe be a Jetbrains solution? Since I would trust that more than another random company which is less invested in the Kotlin ecosystem.

I think the first step is to start filing bugs on librariers to migrate off of Bintray / JCenter. I filed https://github.com/valich/intellij-markdown/issues/64 - which is a dependency of Dokka.

I guess I'm not submitting new versions of my personal libs for a while, given that Maven Central requires signing files, and signing within GitLab CI is just begging for someone to steal the keys. Hopefully someone builds an alternative soon.

does KMP have a built-in handy dandy cross-platform mechanism that approximates the functionality of ServiceLoader, or do I just need to bite the bullet and have this process be slighlty more manual?

please help me for this case, I need recursively copy and transform the value form a map to another one, but received Type mismatch error. How to resolve and thanks very much

private fun transformDepsRecursively(target: Project, from: Map<*, *>, to: MutableMap<*, *>) {
    log.quiet("$TAG transformDepsRecursion start")
    from.forEach {
        val valueFrom = it.value
        var valueTo = valueFrom;
        if (valueFrom is ProjectDescriptor) {
            valueTo = target.project(valueFrom.path)
        } else if (valueFrom is Map<*, *>) {
            valueTo = mutableMapOf<String, Any>()
            transformDepsRecursively(target, valueFrom, valueTo)
        }
        to[it.key] = valueTo
    }
    log.quiet("$TAG transformDepsRecursion end")
}

anybody knows what’s the best way to figure out which dependencies on your 20+ modules android project resolve to just jcenter?

Is there a channel here to track issues with 1.4.30? I'm upgrading one of my libraries and am encountering a problem compilation (this happens when I make an inline class constructor private). Just want some advice to see if anyone else here is also experiencing this before raising an issue:

> Task :values4k:compileTestKotlin FAILED
e: org.jetbrains.kotlin.codegen.CompilationException: Back-end (JVM) Internal error: wrong bytecode generated
   L0
    LINENUMBER 17 L0
    ALOAD 0
    ILOAD 0
    INVOKESTATIC Money.constructor-impl (I)I
    IRETURN
   L1
    LOCALVARIABLE this LMoney; L0 L1 0
    LOCALVARIABLE value I L0 L1 1
    LOCALVARIABLE $constructor_marker Lkotlin/jvm/internal/DefaultConstructorMarker; L0 L1 2
    MAXSTACK = 2
    MAXLOCALS = 3
File is unknown

I have an question regarding the new "value class" (successor of "inline class") from 1.4.30: it states: "From now on, Kotlin requires the

@JvmInline

annotation before a class declaration for the JVM backend". Is that only required for Java compatibility or do I have to add this to all value/inline classes going forward for all my JVM code, even for 100% Kotlin code?

Hey, Community! 👋 Today we've released Kotlin 1.4.30 K. More information about it you can find in this blog post. And precisely this release is essential to us, and hope to you. And here is "Why?". In Kotlin 1.4.30, we've announced the Beta stage of the new JVM IR backed. This article describes what it is and why it's important to enable it. But let me repeat the article's central thesis here: please, switch on the JVM IR backend and build your project. And if you will face any problems, please use the YouTrack link or this Slack channel to submit your concern or ask a question. This version of the JVM backend compiler becomes a default one since 1.5. So, we need to test it very-very well, and for that, we call the Community for this kind of activity. And we hope you will answer our call. With love, Kotlin Team.

Hi! Maybe someone here knows a better way to solve issue I have. I have to parse custom byte array into class. I want end class to be immutable. Currently this is my workflow

private class InternalParamDefinition {
    var id = 0
    var type: Byte = 0
    var defaultValue: Any? = null
}

object ParamLoader {
    @JvmStatic
    fun load(id: Int, bytes: ByteArray): ParamDefinition {
        fun createInternal(): InternalParamDefinition {
            val param = InternalParamDefinition()
            param.id = id
            val buffer = PacketBuffer(bytes)

            while (true) {
                when (buffer.unsignedByte) {
                    0 -> return param
                    1 -> param.type = buffer.byte
                    2 -> param.defaultValue = <http://buffer.int|buffer.int>
                    3 -> param.defaultValue = buffer.string
                    else -> throw IllegalStateException("unknown field type")
                }
            }
        }

        val internalParam = createInternal()
        return ParamDefinition(
            id = internalParam.id,
            defaultValue = internalParam.defaultValue,
            type = internalParam.type
        )
    }
}

I have heard ideas about using Protobuf. Maybe there is some better way to do this?

I've got someone that's having issues joining the channel and thinks he's getting caught in a queue, any admins able to give me a hand?

How can I pass values from a flow obtained inside a function to a flow defined outside of it?

val publicFlow: Flow<State> = flowOf(..)
fun doSomething() {
    launch {
        val localFlow = someService.getStream()
        // i want to expose values from localFlow through publicFlow here
    }
}

Hello, I am getting

Class 'tz.co.asoft.IPrinciple' is compiled by an unstable version of the Kotlin compiler and cannot be loaded by this compiler

using kotlin 1.4.30 JVM/IR

Class '<http://tz.co|tz.co>.asoft.IPrinciple'

was compiled by kotlin 1.4.21 JVM/IR. Is this expected? Do all my dependencies need to be recompiled by 1.4.30?

Hey folks, I brief question to explicit API mode in 1.4. First of all, it’s really nice, thanks! The question: why does it demand

public

modifier for public interfaces’ methods? It’s not like you can type anything else there anyway, looks redundant.

Hi guys... Is there a way to sort a map/Hashmap using both the keys and values. For instance:

[Elijah=51, Chloe=144, Natalie=207, Jayden=390, Elizabeth=485, Matthew=485]

In this map, I would like values to be sorted in a descending order first. Then sort the keys in an alphabetical order. i.e

Elizabeth

must appear before

Matthew

even though their values are the same. 🤷‍♂️

when calling a

suspend

function within

runBlocking

, the following code should not be executed until the function completes, correct? I am seeing some flakiness in a test that doesn't make sense to me.

Hi all - qq about what's possible with Kotlin: Assume I want to convert between two types. One of type

interface A

and one of

interface B

is there a way to write a generic convert function using 

inline reified

 that will convert A to B if and only if a conversion function 

fun(a) : B

  exists?

Is there a way to enable

kotlin.result

in commonMain source set? I tried all the solutions below(in the thread), and it still shows me the error. However it worked on the other targets.

I am trying to play around with value and inline classes on the kotlin playground but it has an unresolved reference to the JvmInline annotation, and specifically importing

kotlin.jvm.JvmInline

leads to a

This declaration is only available since Kotlin 1.5 and cannot be used with the specified API version 1.4

is there a specific way to get this to work in the playground currently?

I have a question which is more design pattern related than Kotlin related (I'm not sure where to even ask this). Say you have an API endpoint

POST /endpoint

which requires posted json data to be of a specific json structure. You then mutate this data into something that goes into your database. Where does this mutation take place? On your repository, or something before that and after the endpoint handler?

Hello everyone, does one of you remember an article/pdf that basically recommended to use Kotlin, aimed for management? I remember that there was a great write up that lots of people referred to, but I can't find it anymore. Our team already uses Kotlin and I will make a little showcase/intro (30min) for out other IT teams, so also having something ready for management would probably help. Thanks a lot!

Do you talk about Kotlin in Action

Hey does anyone have any clue what could be going wrong here? Maven ran from the

maven-wrapper

fails to compile my project with this error:

[ERROR] Failed to execute goal org.jetbrains.kotlin:kotlin-maven-plugin:1.4.30:compile (compile) on project my-project: Compilation failure: Compilation failure:
[ERROR] /Users/poohbar/IdeaProjects/my-project/Controller.kt:[23,30] Unresolved reference: of

The line that it fails on looks like this:

val path = Path.of(folder, file)

And replacing it with:

val path = Paths.get(folder, file)

solves the issue. So bizzarre. 😮

I enabled the new 1.5 experimental features as outlined below using the "compileKotlin" block with language/api verison as 1.5. This works except I get errors on an additional test sourceSet "Task :compileLongTestKotlin FAILED" "Class 'xx' is compiled by a pre-release version of Kotlin and cannot be loaded by this version of the compiler. I had the same issue with my test folder so added "compileTestKotlin" block with the 1.5 options which worked. Adding the same for my additional sourceset results in "Could not find method compileLongTestKotlin()" https://blog.jetbrains.com/kotlin/2021/02/new-language-features-preview-in-kotlin-1-4-30/#sealed-interfaces