i'm SOL, right?

if (nullableIntOne ?: 0 < nullableList?.size ?: 0) {
    // some code 1
} else {
    // some code 2
}

I can't compare nullable types. So what is the likelihood of above code breaking. How can I mitigate it?

Hello everyone. Does anyone know how to properly protect collection type properties? What I want to do is to clone the collection into an immutable one every time

get()

is called. However, I just found out that defining something like,

var myCollection: MutableList<String> = mutableListOf()
    private set
    get() = field.toMutableList()

is problematic because calling

this.myCollection

within the class itself seem to call the getter instead. My current alternative is to make it immutable collection and replace it every time there are changes. However, that seems to be a little more work than it should be. Any ideas?

Hi, everyone I am continuing to learn gradle things. If I create an multiplatform project in Idea it will have two build.gradle files inside. One is the root with following content :

buildscript {
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.0'
    }
}
repositories {
    google()
    jcenter()
}

Why we need repositories here? According to docs it configure repositories for current project. But this is the root file. And it have repositories inside buildscript. This repositories didn't count for subprojects (whats why child build.script have it's own repositories closure). If I remove it - nothing changes, app still build and run (at least on Android). In Android studio this closure looks like :

allprojects {
  repositories {
      google()
      jcenter()
  }
}

Which is quite understandable. Maybe I am missing something and this repository closure have some purpose?

Checkout this webinar on how Kotlin is making our lives as engineers easier at Intuit: http://bit.ly/Kotlinwebinar

Is it possible to seamlessly wrap something like an

Optional

? Where there are three valid values: regular value, null, nothing. I'm using a data class so a

lateinit var

isn't exactly the best solution

So I am trying to work on my first Kotlin/Native project and hit a snag when trying to use

BigDecimal

. Since it is a Java stdLib object, I don't have access to it. I need to do some pretty high precision math that I don't want to be in base-2, are there any good Kotlin alternatives?

Are any of the channels here an appropriate place to ask a question about using Gson with Kotlin? Gson or Retrofit, really.

anyone want to give me their philosophy of when to use data classes vs interfaces?

does Kotlin have an easy way to have non-blocking file IO?

Coroutines

sealed class Operation <out T> {

   data class InsertOperation<out T>(var insertedData: ArrayList<T>)
}

Hi, this gives

type parameter t is declared as 'out' but occurs in 'invariant' position in type t

, can anyone tell me what is correct way of handling this type of variance checking?

So I got an IntelliJ out of memory error, and now all my Kotlin projects which were building fine in IntelliJ, are peppered with red all over the place. Example errors are listOf, it and lazy being an unresolved reference. The projects are gradle based and still build perfectly in gradle, Any ideas ? IntelliJ 2019.1.3 ultimate, Kotlin plugin v1.3.41-release-IJ2019.1-1

Java/Kotlin question about NonNull and primitive arrays:

@Value
public final class Url {
  @NonNull
  private URL url;
  @NonNull 
  private byte[] signature;
}

but in Kotlin it's always treated like

ByteArray!

. Apart from that, NonNull is marked with warning: primitive type members cannot be annotated. Any idea what could be wrong? NonNull annotations are from checker framework.

Yo guys how many job openings are there for kotlin? I got pretty comfortable with it but whenever i look at job offers its all java and if you know kotlin its just a bonus

Anyone using exclusively Spock to test Kotlin classes? I'm seeing some issues with using a Spock Mock for a Kotlin interface where the stubbed methods are returning null. Wondering if there's something odd with the interop that I'm missing...

Hi, I have updated kotlin 1.3.21 to 1.3.41 and I'm getting IDE errors about type mismatch, This happens with requery library : Type mismatch. Required: Condition<out Expression<TypeVariable(R)>, *> Found: Logical<out Expression<Long>, Long> I know Logical inherits from Contidion but type can't be inferred . Any Workaround?

anyone seen this from idea?

Exception in thread "main" java.lang.NoClassDefFoundError: kotlin/jvm/internal/Intrinsics
	at com.potreromed.ApplicationKt.main(Application.kt)
Caused by: java.lang.ClassNotFoundException: kotlin.jvm.internal.Intrinsics
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 1 more

I get it when trying to run a very simple application class...

@SpringBootApplication
open class Application

fun main(args: Array<String>) {
    runApplication<Application>(*args)
}

I have used Klaxon for JSON parsing for a bit but I can’t find if there is a function to merge JSON documents. Anyone know if there is one? If there isn’t anyone know of a good lib for this?

i have a generic class and want to define an inner interface to define a handler for that type (which would include the generic). i.e.:

class Foo<T> {
   ...
   inner interface FooEventHandler {
     fun event(value: T)
   }
  }

but it looks like this isn't possible (it says

inner

can't be used with

interface

). is there a good way to accomplish something like this? i don't want the user to have to define the generic type in 2 places (once for Foo and once for instantiating a FooEventHandler, because it could only lead to a mistake)

Folks, how can I use Flow in a similar manner of ConflatedBroadcastChannel? I want to send a message coming from UI to a stream. BroadcastChannel had an offer method, what do I do with Flow ?

Hey there! What would be an appropriate channel to discuss gRPC style and best practices in Kotlin?

Hi! Where i can find retry function?

Hi, is where any way to look into source code of Gradle task(s) added by plugin ( I mean Kotlin-Multiplatform and I guess Android plugins )?

Hello everyone, does anybody have any experience with MockK? I'm currently stuck on a stackoverflow error due to mocking functions of an interface but without any special behaviour...

Any Moshi experts here?

Having a question with respect to using the

?:

elvis operator to provide a default: If I have reasonable tests around code that does something like:

val x = nullableObject?.method() ?: default

JaCoCo tells me I have one of 4 branches uncovered. If I change that to:

val nullableX = nullableObject?.method()
    val x = nullableX ?: default

JaCoCo tells me all branches are covered (2 branches per line). I'm guessing the "uncovered" branch is when

nullableObject

is non-null, but

method()

returns null -- is there a way to get JaCoCo to realize that branch is not possible based on

method()

not being nullable? Or is there a better practice here?

maybe this is a dumb question: can i create an instance of a private inner class from the outer class? i'm getting a runtime error about

java.lang.VerifyError: Call to wrong <init> method

Out of curiosity, is there a reason why the parentheses of a function without parameters are not optional?