kotlinlang #announcements

inline fun <reified T> calc(p: String): T? {
  return if (null is T) {
    println("nullable")
    null
  } else {
    println("not nullable")
    "foo" as T?
  }
}

fun main() {
  calc<String?>("hello")
  calc<String>("hello")
}

elect

12/04/2018, 9:48 AM

I noticed that simple

val

inside `object`s are translated in java as

private

, while

const val

are

public

.. why?

❓ 1

Bernhard

12/04/2018, 12:43 PM

I basically want to validate composite unique constraints

ziggy42

12/04/2018, 1:15 PM

The problem is this I'm using

kartikpatodi

12/04/2018, 1:31 PM

is there any support for java 9/10 modules in Kotlin?

heruan

12/04/2018, 2:18 PM

Hello, is this channel okay for questions related to IDE plugins?

Tasos Stamadianos

12/04/2018, 4:18 PM

where can I ask questions about binary compatibility and JVM/JDK versions?

Casey Kulm

12/04/2018, 5:19 PM

When I use the “Create Test” feature in Intellij, it always creates it as a Java file even if I put it in the kotlin source set. I usually end up converting it right away. Is there a way to have it be generated in Kotlin instead.

Davio

12/04/2018, 6:06 PM

@Paul Woitaschek maybe you have to generify the function, not just the parameter?

karelpeeters

12/04/2018, 6:30 PM

No, but at least that makes it theoretically possible 😏

fitzoh

12/04/2018, 8:10 PM

Copy code

`in`.doSomething()

? 😆

dknapp

12/04/2018, 8:12 PM

Untitled.kt

Davio

12/05/2018, 8:38 AM

Why not

it

➕ 6

arve

12/05/2018, 9:46 AM

Hello friendly Kotliners! I have an interface with a fun that returns some custom related datatype:

Copy code

package somePkg

interface MyInterface {
  fun myFun(): MyType
  data class MyType
}

I don't want to pollute

somePkg

with

MyType

, since it's pretty specific to the domain of

MyInterface

, and there is other stuff in the same package. Are there any pitfalls to defining a data class inside an interface that I should be aware of? What about putting it inside companion object inside the interface? Is the only difference in the import statement you have to use?

Ayoub

12/05/2018, 11:59 AM

Hello can anyone explain to me the highlited line

karelpeeters

12/05/2018, 2:44 PM

Copy code

fun IntRange.clamp(value: Int) = when {
    value <= start -> start
    value >= endInclusive -> endInclusive
    else -> value
}

Tsvetozar Bonev

12/05/2018, 3:01 PM

-.kt

Alan Evans

12/05/2018, 3:02 PM

Or.txt

orangy

12/05/2018, 3:02 PM

📣 📣 📣 Webinar is live! Join now done, watch the recording!

https://www.youtube.com/watch?v=FAhR_sqlUy4▾

👍 11

Andrew Gazelka

12/05/2018, 4:47 PM

is it proper to use

check()

for private method logic errors?

Casey Brooks

12/05/2018, 5:25 PM

Kotlin does not support using properties to override Java getter/setter methods, and likely never will (see this SO comment https://stackoverflow.com/a/47454364/2469169 for more context). You should be able to override it just as a method, mapping it to a differently-named Kotlin property

Copy code

data class Document(
    val _resourceId: String
) : Resource {
    override fun getResourceId() = _resourceId
}

Hullaballoonatic

12/05/2018, 9:06 PM

I think of kotlin as one of the easiest languages to program in that you don't accidentally throw exceptions you didn't expect when writing... So why unlike java, does kotlin not need the

throws

extension to methods and classes that java does whenever anything they contain will throw one?

Icaro Temponi

12/05/2018, 11:15 PM

Or is in this specific case the experimental status of these features tied to the version of the library (coroutines), not the language?

Marcin Wisniowski

12/06/2018, 2:07 AM

Hello, I am using

joinToString(", ")

to construct a comma separated string from a list of names. What would be an idiomatic way to make the last comma an "and" instead? I am getting "a, b, c, d", but want to get "a, b, c and d". I can replace it afterwards, or join all the names except the last one and add it separately, but maybe someone here has an elegant solution I'm not seeing? This is the best I can currently think of:

names.dropLast(1).joinToString(", ") + " and " + names.last()

spand

12/06/2018, 9:06 AM

Is it possible to access

isInitialized

on a local variable (ie. not property)

lateinit var

? If so what is the syntax

Tsvetozar Bonev

12/06/2018, 1:23 PM

Can't seem to get the generics to work with a Class object

Jonathan

12/06/2018, 4:15 PM

Hey, why the Kotlin compiler needs to box inline classes when used with generic classes (like list) ??

Rohan Maity

12/06/2018, 4:30 PM

Limit-Breaker: I was Reading about Coroutines in Kotlin "Kotlin coroutines are stackless , they don't have their own stack" "Threads are managed by OS and Coroutines managed by Users " What does this mean ? How Kotlin coroutines manages to unblock thread while suspending the functions ?