Is there a kotlin only replacement for the java method

Character.getNumericValue()

? It would be useful in kmp but i can't seem to find one.

hello, on the https://discuss.kotlinlang.org/ website when trying to log in I accidentally selected the wrong Google account, and now I am not able to select the correct one because it keeps trying to get me to create that new account when I click "Log In". is there any way to "log out" of this non-existent half-created account?

I’m going crazy getting my

freeCompilerArgs

working. I’m still getting errors/warnings with what I have tried below. This is in the

build.gradle

of a module.

android {
    kotlinOptions.freeCompilerArgs += compilerArgs
}

and

tasks {
    withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().configureEach {
        kotlinOptions.freeCompilerArgs += compilerArgs
    }
}

…. more in thread 🧵

I have a list of people and each person has a TYPE. Either DIRECTOR, PROFESSOR or STUDENT. How do I sort the list so that all students are listed after the DIRECTORS and PROFESSORS? As a first approach to this, I think it would just be easier to just have two identical lists. filter out the students from list 1. and then filter out prof and directors from list2 and add them together.

Hello! I don't know if this is the right place (didn't found any JVM specific channel). We have a Kotlin JVM service which is not attached to any web framework, such as Spring. Still, we want to standardize it with hexagonal architecture and I was wondering about dependency injection. I came across this lib (https://github.com/Kodein-Framework/Kodein-DI/). Has someone used? Is there any other alternative?

I'm not sure what this error is trying to tell me:

Exception in thread "DefaultDispatcher-worker-3" java.lang.ClassCastException: class kotlin.reflect.jvm.internal.KTypeImpl cannot be cast to class kotlin.jvm.internal.TypeReference (kotlin.reflect.jvm.internal.KTypeImpl and kotlin.jvm.internal.TypeReference are in unnamed module of loader 'app')

at kotlin.jvm.internal.ReflectionFactory.mutableCollectionType(ReflectionFactory.java:107)

at kotlin.jvm.internal.Reflection.mutableCollectionType(Reflection.java:196)

at io.github.jan.discordkm.api.entities.interactions.commands.builders.ChatInputCommandBuilder.build$DiscordKM(ApplicationCommandBuilder.kt:211)

at io.github.jan.discordkm.api.entities.containers.CommandContainer.create(CommandContainer.kt:29)

at io.github.jan.therealbot.MainKt$main$$inlined$on$default$4.invokeSuspend(DiscordWebSocketClient.kt:171)

at io.github.jan.therealbot.MainKt$main$$inlined$on$default$4.invoke(DiscordWebSocketClient.kt)

at io.github.jan.therealbot.MainKt$main$$inlined$on$default$4.invoke(DiscordWebSocketClient.kt)

at io.github.jan.discordkm.api.events.EventListenerKt$EventListener$1.onEvent(EventListener.kt:21)

at io.github.jan.discordkm.api.events.EventListener$DefaultImpls.invoke(EventListener.kt:16)

at io.github.jan.discordkm.api.events.EventListenerKt$EventListener$1.invoke(EventListener.kt:20)

at io.github.jan.discordkm.api.entities.clients.DiscordWebSocketClient$handleEvent$2$1$1.invokeSuspend(DiscordWebSocketClient.kt:101)

at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)

at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)

at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571)

at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750)

at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678)

at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665)

Not super comfortable with sealed classes. I'm trying to model an action type that can model things like a phone button click, or a url click, or unhandled (unknown). How does this look?

sealed class GenericActionType {
    class Dialer(phoneUri: String) : GenericActionType()
    class Browser(url: String) : GenericActionType()
    object Unknown : GenericActionType()
}

Hi, in a situation like this: https://pl.kotl.in/vK8g6iJtG is there a way to implement this interface while keeping the

username

part of the primary ctor and without changing its name?

Hi all, I’m fairly new to Kotlin. I’m trying to implement the below code. The

getCurrentSubscription

method returns a `Subscription?

nullable type. Doing a

.let` makes the

it

also type of

Subscription?

. I though .let should pass on a non-null

Subscription

inside. Now my

cancelSubscription

method expects a non-nullable

it.id

which is causing issues. What am I missing here?

getCurrentSubscription.invoke(customerId).let {
      cancelSubscription.invoke(it.id, cancelled).let { subscription ->
        subscriptionApiMapper.fromDomainModel(subscription)
      }
    }

today lesson is about some witchcraft.. how the hell can they at Facebook have such a syntax:

typealias BatchSize = 100
typealias Height = 40
typealias Width = 50
  
fun getFirst(
  input: Tensor<[BatchSize, Height, Width]>
): Tensor<[Height, Width]> {
 ...
}

typealias

integer values or square brackets in type parameters..?

if (nullableVarParent?.nullableValChildOne == null
         || nullableVarParent?.nullableValChildTwo == null) 
      return
    
funcEx(
     nullableVarParent?.nullableValChildOne!!,   
     nullableVarParent?.nullableValChildTwo!!
)
...

I had a discussion with a college about how unsafe the previous code is, to use (!!) operator even after "if condition". He is totally convinced that the mutable parent is impossible to be null after the if condition since we don't use threads in this area. His words are some how believable but since everyone in the world has been saying to avoid suppression (!!) in all cases, I wanted to make sure. what do you think might be dangerous about this?

hey guys, what is the equavilant of this python code

s = "string"
list = [s * 10]

basically, I just want to create a list of objects each of them is the same string actually

I've encountered a strange type mismatch error with 1.5.31 and am not sure if it's a bug. Consider the code in the attached snippet. The

compiles

method compiles without issue, but if I save the expression to a variable instead of returning it, it complains about a type mismatch.

I've got this generic function: https://pl.kotl.in/cv6sdbHHy

Hi, I want to parse a simple date, and I don't know why this doesn't work

val versionDate =  "May 5, 2009"
	val formattedDate = SimpleDateFormat("MMM d, yyyy").parse(versionDate)
	println(formattedDate)

What am I doing wrong ?

I have a behavior that I want a majority of my ViewModel classes to support. I considered creating a BaseViewModel, but I have also seen base classes that get out of control with if statements everywhere, and then it becomes clear that a base class wasn't the right approach. I have seen the statement "favor composition over inheritence", but I haven't seen a practical example of it ever (or maybe I just never connected the dots). How would I make a class have this sort of behavior be composable (not to be confused with jetpack compose) instead of using inheritence? Do I just use interfaces since I can define multiple interfaces to implement? (I know that this is sort of not necessarily kotlin, but I figured it'd be worth a shot asking here)

I was just experimenting with the

String.split

functionality and came across this situation which made me curious. I found that running this:

"hello".split("")

produces this

["", "h", "e", "l", "l", "o", ""]

. I didn’t expect for there to be empty strings on the start and end of the returned list only that the list would be made up of each character from the original string. To clarify, I’m not asking about the best way to iterate characters in a string or how to get them into a list, just curious about the implementation of

split

with an empty separator and why the empty strings were appended to each end of the resulting list?

I want to do parallel computations over collections and do parallel for loops. Java Streams with parallel for the first case? And the second case?

The Kotlin plugin reports private properties overriding public methods of extended Java classes. Does anyone encounter the same issue?

Is it normal to spend more then a month trying to understand generics?😅

I'm not sure I follow the use case for Kotlin's

Duration

it seems to be missing

.between

? So I need to use Java's, in which case I can't use Kotlin's because importing both doesn't work? What am I missing?

I'm trying to convert a long amount in euro cents to a readable value. I'm not European and I see conflicting information on this. Here is my ext func

fun Long.euroCentsToString(): String {
    val format = NumberFormat.getCurrencyInstance()
    format.maximumFractionDigits = 2
    format.currency = Currency.getInstance("EUR")

    return format.format(this/100)
}

If I call

849999L.euroCentsToString()

I get a result of

€8,499.00

I thought what I'd get is

€8.499,99

So Basically three issues: 1. I thought europeans use

.

to separate thousands from hundreds 2. I thought europeans use

,

to designate the start of fractional (cents) 3. I thought I'd see 99 as the cents and not 00.

Hi, I'm doing advent of code 2021 and I have a very very very weird bug where my console is broken and only display a fraction of the lines, when I execute this code :

val data = readFile("day1.txt")
val pairs = data.trimEnd().split("\n").zipWithNext().toMap()
val result = pairs.count { a ->
	return@count a.key == a.value
}
	
pairs.forEach { println("key=${it.key}, value=${it.value}") }
	
println(result)

I don't get the

key=something

part in my console

If I define a function outside a class and want to access it with reflection, under which 'class' do I find it?

Hey, how could I calculate a run length encoding elegantly for arbitrary types (not just strings but based on

equals

). E.g. how to transform

listOf("A", "A", "B", "C", "C", "C", "C", "A", "A")
// to
listOf("A" to 2, "B" to 1, "C" to 4, "A" to 2)

groupingBy method

hi everyone, Q: Do 'Sealed (exhaustive) 

when

 statements' break OCP(open-closed-principle) ? I saw the new sealed when compiler feature on Kotlin 1.6.0 and shared it to my team, thinking we could use it, but there was an opinion that this kind of logic breaks the ocp rule because, If you add new inheritors to the sealed class(or interface), you would have to change all the when statements that take that sealed class(which is the parent class) and thus, ocp is broken Would this be true? We agreed that the oop rules were made before sealed classes/interfaces were introduced and this might be the "trend" of programming languagues, but still some are hesitant to use it. Any kind of related opinion & reading material is welcome to be shared,, thanks!

Is there some way to create range withou having to sort it first? I mean,

10..0

creates empty range, and I have to change it to

10 downTo 0

. But I don't want to bother with it. I would expect

10..0

to do it automaticaly.

If I have a string array: ```<string-array name="listOfNorthDishesArray"> <item>{"name":"Khai Paen","details":"River weed is turned into thick, simmered, spicy sauce or dried in thin sheets which have been sprinkled with tamarind and ginger juice and other aromatics such as sesame seeds, tomato and garlic. The dry sheets are cut into small squares and flash shallow fried for a tasty drinks snack."} </item> <item>{"name":"Jeow Bong","details":"Jeow bong is eaten with fried or grilled river algae sheets kai paen or kai phene, grilled dried beef gee sin lod or steamed vegetables. It is also served as an accompaniment to sticky rice or added to stir fries."} </item> </string-array> how can I return just "name" here

resources.getStringArray(R.array.listOfNorthDishesArray).toMutableList()

Is it good practice to keep your sealed/data classes outside of the class that uses it, or is it better to keep it inside? 1️⃣

class MyViewModel : ViewModel() {
    sealed class SelectedFolder {
        object Unselected : SelectedFolder()
        data class Selected(val id: String) : SelectedFolder()
    }
}

or 2️⃣

private sealed class SelectedFolder {
    object Unselected : SelectedFolder()
    data class Selected(val id: String) : SelectedFolder()
}

class MyViewModel : ViewModel() {