When i call a method defined in java as

<T extends View> T findViewById(int id)

, why do i need to specify

<View>

? Shouldn’t the compiler default the type to

View

if I don’t specify something more concrete?

it has nothing to infer from. kotlin’s generics are more strict than the java equivalent

but it seems like that would fail in java as well

it doesn't

there's a couple issues about bounds inference but none seem to cover this case

What is the kotlin Uast plugin?

It's Universal Abstract Syntax Tree. AST that allows to work with Java and Kotlin using the same API. Used for example to write universal static analysis checks

is there any way to test

@Deprecated(level = ERROR)

functions without the overhead of an entire project?

i have an extension function annotated with it that is an overload on a more specific receiver type than another extension function

i.e.,

fun Base.whatever()
@Deprecated(level = ERROR) fun Impl.whatever()

i have a test for

Base.whatever()

whenever

Base

is actually an

Impl

, but I'd like to test that when you have an

Impl

and you call

whatever()

you receive an error.

I guess I need a compile-testing but for Kotlin

You can use one of the embeddable forms of Kotlin compiler, run only frontend and inspect emitted diagnostics, comparing them to what they need to be. No out-of-the box solution, I’m afraid.

That sounds very close to what compile-testing does for Java. I'll give it a shot when I find some time. Thanks!

Is there a way I could override

get()

on a property from my primary constructor in a data class?

make it private and expose a public property outside of the constructor derived from it?

is it possible to extend a Java class with a property that has a getter/setter, and override that property as a kotlin property rather than overriding the getter/setter?

Specifically, I want my kotlin class to implement an interface and when working with the interface I want to be able to use the property forms. However, I can't put these values into the interface as properties because they conflict with the java getter/setters

@dumptruckman You want to override getters and setters with properties? That's not possible, but it's a common feature request. See for example this issue: https://youtrack.jetbrains.com/issueMobile/KT-6653

@User uploaded a file: Untitled

@karelpeeters it looks like my situation is slightly different but yeah, look related

@dumptruckman Isn't the problem there that you basically have a conflict?

I'd be interested in seeing how the bytecode for that interface even looks, it seems like it would require

getValue

twice.

Given the following:

fun <I, O> Collection<I>.flatMap(func: (I) -> List<O>): List<O> = TODO()
fun <I, O> Collection<I>.flatMap(func: (I) -> Collection<O>): Collection<O> = TODO()
fun <I, O> List<I>.flatMap(func: (I) -> Collection<O>): Collection<O> = TODO()

fun main(vararg args: String) {
  val collection: Collection<Int> = listOf(1)
  listOf(1).flatMap { collection }
}

This currently fails with:

Error:(7, 12) Cannot choose among the following candidates without completing type inference: 
public fun <I, O> Collection<Int>.flatMap(func: (Int) -> Collection<???>): Collection<???> defined in root package
public fun <I, O> Collection<Int>.flatMap(func: (Int) -> List<???>): List<???> defined in root package
public fun <I, O> List<Int>.flatMap(func: (Int) -> Collection<???>): Collection<???> defined in root package

If I specify

flatMap<Int, Int>

explicitly, I then get:

Error:(7, 12) Overload resolution ambiguity: 
public fun <I, O> Collection<Int>.flatMap(func: (Int) -> Collection<Int>): Collection<Int> defined in root package
public fun <I, O> Collection<Int>.flatMap(func: (Int) -> List<Int>): List<Int> defined in root package
public fun <I, O> List<Int>.flatMap(func: (Int) -> Collection<Int>): Collection<Int> defined in root package

Is this expected? I would think that given the type information, the third function would match. But even without explicit type information, I would expect it to match. The receiver type is the most specific and then function signature matches perfectly.

Has anyone tried to make a project that uses both the

kotlin

and

kotlin2js

plugins? When I try, I get an error that says

Cannot add extension with name 'kotlin', as there is an extension already registered with that name

. I initially tried with the kotlin gradle dsl, but it doesn't work with the groovy dsl either. My only thought is that I might be able to do it with a multi module project, and separate the js and jvm code bases.

That's what you have to do, yes

How come you can't have a getter inside a function? I can do

val test: String get() = "test"

outside of a function or inside of a class, but not

fun main(args: Array<String>) {
    val test: String get() = "test"
}

you can't

guys whats the lattest gradle version and android plugin version that you se for kotlin

official releases only