I’m having issues with intellij not recompiling when I edit an inline function. I need to “rebuild project” for the change to take effect. known issue?

(trying to adapt https://stackoverflow.com/questions/36253310/how-to-get-actual-type-arguments-of-a-reified-generic-parameter-in-kotlin to get a

KType

rather than a

Type

)

@neuber This line here:

buttone1.setOnClickListener { viewModel.setDrawable() }

You can change it to something like this:

buttone1.setOnClickListener { viewModel.setDrawable(context = this) }

Then change the function you are currently editing to this:

fun setDrawable(context: Context) {
    back.setDrawable(context.getResources()./*the rest*/)
}

That should help

This guide shows quite different settings form what the wizard did: https://kotlinlang.org/docs/reference/using-maven.html E.g. it specifies

sourceDir

for the Kotlin plugin, should I do that? And why does it replace the execution for the java compiler plugin in the guide?

<!-- Replacing default-compile as it is treated specially by maven -->

How specially? What? What does that mean? Why is the documentation so bad?

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <executions>
        <execution>
            <id>default-compile</id>
            <phase>none</phase>
        </execution>

What does this do? There is nothing about

default-compile

goal anywhere in Maven docs.

I'm trying to access the children of a sealed class via a typealias, but it fails with

Unresolved reference

. Is that generally impossible?

sealed class LoginScreenAction {
  object NameEntered : LoginScreenAction()
  object SubmitClicked : LoginScreenAction()
}

private typealias Action = LoginScreenAction

fun main() {
  println("My action is: ${Action.NameEntered}")
}

Is there a simple way of modifying a file?

Is there no way to construct an anonymous instance of a SAM-ish abstract class from a lambda? For example:

//java code
public abstract class Test {
    public abstract void run()
}

//kotlin code
fun testFoo(test: Test) = test.run()

fun main(args: Array<String>) {
    testFoo(object : Test() {
        override fun run() {
            println("hey")
        }
    })
}

It just feels unnecessary, are there plans to do something about this?

Hi everyone, I'm creating a kotlin cheatsheet for myself while I learn the language. Kindly feel free to contribute to the repo. https://github.com/alfredayibonte/kotlin-cheat-sheet

Hi. For a subtree of our class hierarchy we have interface method

apply

whose argument is a SAM from guava. Since some of us started using :kotlin: we bump into the conflict with Kotlin's

apply

quite often. I'm considering the resolution options and so far found only two. Did I miss anything? 1. rename member

apply

to something like

applyFunction

(involves convincing several teamleads who do not use :kotlin: ) 2. specify the receiver type (

someInstanceOfBase.apply<Base> { ... }

) (suggested by @marstran) 3. accept that this is the reality and use

also

instead of

apply

4. duplicate Kotlin's

apply

and rename that (suggested by @karelpeeters) Here's the recipe for the disaster at hand 🙂 (irrelevant parts omitted for brevity) :java:

import com.google.common.base.Function;
public abstract class Base {
	public <T, F> T apply(Function<F, T> function) {
		return function.apply((F) this);
	}
}

Does

someInstanceOfBase.apply<Base> { ... }

work?

I have this Kotlin data class:

class Person(override val id: String, val name: String) : HasId

and this Java interface:

public interface HasId {
    String getId();
}

How do I implement the interface? The above example gives me

'id' overrides nothing

is it possible to access a property or function by string containing its name at run time, like in JavaScript?

I'm trying to emulate https://github.com/JetBrains/kotlin-examples/blob/master/maven/hello-world/pom.xml in my own project, but keep encountering

java.lang.ClassNotFoundException: MainKt

(my main class is

src/main/Main.kt

, the package is called

main

. Any suggestions?

Hey guys, this is a coroutines question: Do coroutines cache the "await"ed results? If that is not the case, how should caching be done?

Is it possible to have an interface which can only be implemented by subclasses of a certain class, and be able to use properties/methods of that super class in the interface? For example in my Android app, a few activities do the same things in onCreate etc, but it seems restrictive to write an Activity subclass and have them all inherit it

I think even Windows does the right thing when it encounters

\n

but I wasn’t sure if in Kotlin,

\n

represented literally ASCII

0x0A

or if it ends up being translated to the proper newline depending on platform

@ayrat555 an

object

by the definition of Kotlin is a class that has a single instance (like a Singleton) and that instance is created automatically at startup, so there is no way to have abstract stuff inside an Object

Perhaps I'm not the first one asking but were the talks at KotlinConf filmed and will the videos be available for everybody?

Inner classes are more expensive, I guess

it's a construct of the language but not the bytecode or runtime

hi Jake, found it 🙂

@tgmcians you have to cast it in some way. ie,

responseBody?.let {
    view?.onUnknownError(getErrorMessage(it))
}

if I wanted to do basic 2d graphics, similar to canvas on the web, what would I choose these days?

O(n)?

Thanks

Can anyone explain what is

reified

I'm unable to understand the concept behind this one

where can I watch kotlin conf recordings?