What is the default indentation for Kotlin in intellij?

what is the difference between these two annotations? @OptIn(ExperimentalCoroutinesApi::*class*) @ExperimentalCoroutinesApi

How can I align console output in Kotlin?

488 -> 488	| 485/500
489 -> 44499	| 486/500
490 -> 70070	| 487/500
491 -> 8838	| 488/500
492 -> 3444	| 489/500
493 -> 7888	| 490/500
494 -> 494	| 491/500
496 -> 992	| 492/500
497 -> 994	| 493/500
480 -> 60000	| 477/500
460 -> 2202020	| 496/500
499 -> 499	| 497/500
498 -> 996	| 495/500
495 -> 990	| 494/500
483 -> 966	| 480/500
500 -> 500	| 498/500
290 -> 11011010	| 499/500
430 -> 11011010	| 500/500

Hi all Could someone please tell me, how can I make the following code more elegant:

class GenderMapper(val id: String, val description: String)

fun GenderMapper.toGender(): Gender {
    val description = this.description
    return Gender.new(id) {
        this.description = description
    }
}

What does

UUID!

mean?

I'd like to have an array of ~1000 Functions (not all are implemented yet) to choose one from at runtime and pass all input arguments (after the first, which is used to choose the function) to. How can I create the array and call from it?

I'm running into an error with my UnitTests. Can't really make sense of the errormessage: - Is this an issue with gradle? The only test atm is a simple @Test assert(true). https://pastebin.com/GZXsiDWL

hey guys, question about idiomatic syntax what is preferable, this

if (event == null) {
    return emptyArray()
}

or this

event ?: return emptyArray()

? note: this is just the first line of the method, then comes more logic

is there something like

TODO("reason")

but meant just for unreachable `if`/`when` branches? (for example like Rust has

unreachable!

macro do designate code paths that can't be taken)

Hi guys, I hope all of you are having a good one! I am doing some projects from Hyperskill, concretely the minesweeper. I managed to create a 2D array which randomly locates mines. After this, I created another array to shows in each position how many mines are around the coordinate. As the array is char, I need to convert the number of mines around the coordinate into a char and here I have the issue. The program runs without any problem but it does not show what it should. Is this some issue I cause?

X is mine

. there are not mines around

The project seems to build fine, and I see it downloading that library, but it then doesn't seem to be in my class path. I feel like I must be skipping some obvious step.

Hi there Is kotlin coroutines based on the java nio or they have their own implementation of non-blocking io?

really simple question. Trying to create a java object that requires setters to be called. Is this the right pattern to use or not

val jsonHeader = HttpHeaders().let {
        it.accept = listOf(MediaType.APPLICATION_JSON)
        it
    }

Let’s say I have a

data class

object:

val state : AppState = AppState()

where:

data class AppState (
  val loginState : LoginState = LoginState(),
  val showingDetail : Boolean = false,
)
data class LoginState (
  val loginVar : String
)

if I want to just change a child property, it’s very simple, it just takes 1 line:

state = state.copy(showingDetail = true)

but it I want to change the property of one child, I need 3 lines:

var login = state.loginState
login = login.copy(loginVar = "my value")
state = state.copy(loginState = login)

is there a simpler syntax to achieve this?

I have a list of these objects

class MyDataObj (
	var a : Int
	var b : Int
	var c : Int
)

What is the most simple way to get an object of the same class, where each variables are the sum of variables of the elements in the list?

so, if:

val obj1 = MyDataObj(1,3,4)
val obj2 = MyDataObj(3,2,3)
val obj3 = MyDataObj(2,4,1)
val list = listof(obj1,obj2,obj3)

I would like to derive

objTot

, which has a=6, b=9, c=8

I have a static list defined in my project. Like this:

val obj1 = MyDataObj(1,3,4)
val obj2 = MyDataObj(3,2,3)
val obj3 = MyDataObj(2,4,1)
val list = listof(obj1,obj2,obj3)

using AndroidStudio/IntelliJIdea, is it possible to run a script, where I experiment a reduce function, without having to run the whole project, but just this script which references an objected defined in my project? In other words, can I run my “playground” inside my IntellijIDEA, which references classes already defined in a projects? I would like to run something like this

println(list.sumBy{ it.a })

Hi there Is there any legal way to convert

private suspend fun containsMatchIn(contentMessage: ContentMessage<*>): Boolean {
        val content = contentMessage.content
        return ((content is TextContent) && !hasCommand(content) && containsInText(content.text))
                || ((content is PhotoContent) && containsInImage(content))
    }

into

private suspend fun containsMatchIn(contentMessage: ContentMessage<*>): Boolean {
        return ((contentMessage.content is TextContent) && !hasCommand(contentMessage.content) && containsInText(val content = contentMessage.content.text))
                || ((contentMessage.content is PhotoContent) && containsInImage(contentMessage.content))
    }

to get rid of the extra variable

val content = contentMessage.content

? Thanks

Hi everyone, I have this simple code and it doesn't run as expect. I want to add an element to an array of int and then I expect it will have 1 element. The current code print 0

val res : Array<Int>  = emptyArray()
 res.plus(1)
 println(res.size)

Whats the correct way to document an enum class?

/**
     * Represents the way two [clauses][Clause] are joined.
     *
     * @property AND Means that this clause and the previous clause should be combined using and
     * (i.e. both need to be `true`)
     * @property OR Means that this clause should be combind with the previous clause using or
     * (i.e. this clause needs to be true or the previous clause needs to be `true`)
     */
    enum class Conjunction() {
        AND,
        OR
    }

Or should the values be on the enums themselves?

Hey, I am migrating my project to kotlin 1.4 and I started running into compiler running out of memory

> Task :compileKotlinJvm FAILED

e: java.lang.OutOfMemoryError: Java heap space

So far I have tried to adjust

Build process heap size

upwards to 8000 megabytes, and have tried to provide a max memory flag of 8g to build process VM options. Neither attempt seemed to make any difference, as the compiler process seems to still max out at around 850mb when it throws an Out of memory exception. Any help would be greatly appreciated.

Hey all, just wondering, why is kotlin stuck on Java 8? Why doesn't it start targeting newer versions?

does anyone have any suggestions for how to handle comparing 2 similar(but not exact) lists. I want to compare the objects in list(generally in same position in either list) A by

key

against list B, and then by a

version

. If value in list B is higher than list A, I want to replace list A with item from list B. I think

compareValuesBy

might work but I’m having trouble sorting out how to implement it fully because elements might be slightly different so I’ll need to scan the list to verify if it’s not found

what do you guys use for mocking in kotlin? I've been using mockito since forever... but with kotling i've run into issues with suspending functions

`when`<Asset>(adapter.assetGetToAsset(input))
   .then {
       delay(300L)
       output
   }

this simple thing I can't do because

then

doesn't give me a coroutine context. Do you use Mockk? Some other libraries? What are the pros and cons? Bonus question: is there some best practice to test when you have final classes? (which are the default in kotlin).

is there something I’m completely missing about using a while loop within a for loop? The while loop is looping over a list of JSwing nodes, the for loop is iterating over a list of items but the for loops only runs a single time then just does not loop, I don’t get it. I originally tried a foreach, and now I’m just adding print statements to try to understand what I’m doing wrong. I know this code is not the cleanest/most correct lol. Learning Kotlin as I go

Hi all! I have a basic doubt but I'm stuck with it... How can I continue and accept an empty input? using this: val scanner = Scanner(System.in) val myNum = scanner.nextInt() I must always insert a number for programm to continue. But I wanted to insert nothing and just press enter for the programm to continue. And this way, myNum val would be empty been googling it, but I think I'm not knowing how to search for it correctly..

can anyone help me with:

e: /home/runner/work/intellij-plugin-ld/intellij-plugin-ld/src/main/kotlin/com/github/intheclouddan/intellijpluginld/settings/LaunchDarklySettings.kt: (155, 21): Unresolved reference. None of the following candidates is applicable because of receiver type mismatch: 
public fun <T> MutableCollection<in ???>.addAll(elements: Array<out ???>): Boolean defined in kotlin.collections
public fun <T> MutableCollection<in ???>.addAll(elements: Sequence<???>): Boolean defined in kotlin.collections
public fun <T> MutableCollection<in String!>.addAll(elements: Iterable<String!>): Boolean defined in kotlin.collections

I’ve tried assigned it to a variable and suppressing that as Unused, I’ve wrapped that section with a

with

block but nothing so far is helping me with this error. Here’s a link to the line in the repo https://github.com/InTheCloudDan/intellij-plugin-ld/blob/master/src/main/kotlin/com/github/intheclouddan/intellijpluginld/settings/LaunchDarklySettings.kt#L155

#introduce-yourself Hello Everybody! My name is Hossam Elbadissi, and my nickname on the web is "Skaldebane". I'm a 16 years old High School student in Morocco, and I've recently switched to Kotlin from Java (a month ago)... Kotlin's amazing features, easy syntax and idiomatic coding made me fall in love with it, and the transition to it was pretty smooth due to its simplicity and similarity to Java. I mostly develop Android applications, though I also like to tinker around with other technologies and try new things... Glad to be here with you, and I'd like to learn more about everything Kotlin, and help shape the future of KotlinLang as it helped me shape mine, in a way or another. Thanks a lot JetBrains, for this amazing language!

how to perform cumProd() operation over a list?