I would like to extend

BaseBuilder

defining a default implementation for

onError()

and hide the

onError()

function to the caller

Why doesn’t the T of

Comparator<T>

have input variance? I was trying to assign a Collator (which for some reason is a

Comparator<Object>

in Java) to

Comparator<String>

. Is it because it’s simply a typealias?

Does anyone have any good resources on integration testing? I’m very new to Kotlin / Spring and I’m just trying to get my head around testing a basic controller, creating the body of the POST request, etc…

With a multi-module gradle project, when using a multiplatform module, all module which have a (transitive) dependency on the multiplatform module must be using the plugin

kotlin-platform-jvm

(and not just

kotlin

even if they don't provide any

actual

) ?

can I mark something as @Deprecated for Kotlin, but not for java? I have some java methods which in Kotlin can be made generic utilizing reified types, for that reason I've written kotlin adapters for them. So on call site I'd like java style

doSomething(Some::class.java)

to be marked as deprecated in kotlin code, and kotlin-style

doSomething<Some>

to be suggested, while in java it should not be marked deprecated.

although it’s not the complete solution. That can be found here https://youtrack.jetbrains.com/issue/KT-4734

honestly just unsafe cast your way to freedom

Huh, my bad.

I know I'm going to get a lot of grief over this, but I'm coming to the conclusion Tuples have a place in Kotlin, primarily for quickly improvising key objects in functional operations. https://github.com/thomasnield/kotlin-statistics/issues/23

some sample would help. but if you want to provide some compatibility with outside consumers:

typealias Coordinate2D = Triple<Int, Int, String>
operator fun Coordinate2D.invoke(x: Int, y: Int, description: String) = Coordinate2D(x, y, description)

@Shawn But the Tuples are statically typed, just nameless.

is there a more elegant way of doing this?

if (!::lateObj.isInitialized) lateObj = LateObj()

where can I read more about kotlin_module files

could someone here give me a quick hand on companion objects?

maybe theres a better one to use?

wait, you want to force subclasses to implement a static field?

Are there planned fetures to kotlin 1.3?

what version of the Kotlin plugin are you using?

Is there a SQL query builder for Kotlin? Something like Squirrel ( https://github.com/Masterminds/squirrel/blob/v1/README.md ). Anko is close but it lacks support for anything complicated (like joins).

I've seen a few typed query builders but they feel too heavy weight to me. I don't want to declare and maintain a schema.

Long

is a subtype of

Long?

Is there any indication as to when this will be fixed?

e: Kotlin home does not exist or is not a directory: 
> Task :buildSrc:compileKotlin FAILED

Really annoying 😞

How about

val a = b?.let { A(it) }

you're out of luck then, for most programmers it does 🙂

Swift can compile

a?.b.toString().length

to

if (a == null) {
  null
} else {
  a.b.toString().length
}

But I think Kotlin is much more natural…

Does swift allow

null.toString()

?

you can in Kotlin as well with a little trick:

fun Nothing?.toString() = "my personal toString"
fun main(args: Array<String>) {
    println(null.toString())
}

Hi, I have a library that every time I use and try to get auto completion it fails with

org.jetbrains.kotlin.resolve.FunctionImportedFromObject cannot be cast to org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor