Hi Mates, i need a help in writing unit test cases for a top level function, if possible can you guys help me to get through this, Stackoverflow question , thanks in advance, apology if i am in wrong channel

<template name="sout" value="println($END$)" description="Prints a string to System.out" toReformat="true" toShortenFQNames="false"> Is it possible to create a live kotlin template like

{statement}.{{templateName}}

? Similar to how doing something like

val x = "hi"
x.sout <Tab> // -> println(x)

ATM, I just duplicated the sout template and added my own, but it doens't work where I call it on another variable. Is that even possible? So I can do something like

x.{{templateName}}<Tab> // -> Something.doSomething(x)

Hi guys. Are these two operations equal in Kotlin?

"""[ \t\f\v]+""".toRegex()
"[ \\t\\f\\v]+".toRegex()

I have a

private val done:MutableSet<T> = mutableSetOf()

in a class. Method

a

starts a thread which calls method

b

, which has

synchronized(done)

. I intermittently get an NPE on

synchronize(done)

. I moved the

private val done

declaration from between

a

and

b

to above

a

and that seems to have fixed it. Am I crazy?

Hi. How to implement properly

equals

and

hashcode

for a data class that contains a

ByteArray

?

Anyone know why type checking hates the

val foo: String? by defaultProperty { null }

? It only goes away by explicitly defining the type of

defaultProperty<String?>

This message was deleted.

why secondary constructor needs to point to base constructor?

Morning 😄 I currently have a sequential operation which uses a

Sequence<T>

myProviders
  .asSequence()
  .sortedBy(configService::getProviderOrder)
  .flatMap { it.getCommitTypes(context.type) }
  .map { CommitTypePsiElement(project, it) }
  .mapIndexed(::CommitTypeLookupElement)
  .distinctBy(CommitTypeLookupElement::getLookupString)
  .forEach(rs::addElement)

Each

provider

call (

it.getCommitTypes(context.type)

) returns a

Collection<T>

and cannot be converted to Flows. I would like to call every provider asynchronously and then

flatMap

the results, and

collect

. How would you approach this in the code above? This part

.map { CommitTypePsiElement(project, it) }
.mapIndexed(::CommitTypeLookupElement)
.distinctBy(CommitTypeLookupElement::getLookupString)
.forEach(rs::addElement)

can remain sequential / blocking.

message has been deleted

hi everyone! i have a question regarding the removal of type parameters from objects in 1.4: what is the reasoning there, and what is the suggested replacement?

Hi all, I have a strange one here... So I'm trying to build a DSL in Kotlin and came across a scenario where I want to combine a set of symbols that are currently dispersed in various different packages behind one single, new package namespace. That way the folks using my DSL to author their own scripts don't have to import symbols from so many different packages. I came up with one idea of using type aliases, but I have so many symbols, I don't want to duplicate these and hard code each alias for all the various entities (not very DRY and difficult to maintain). Example (let's say Alabama is an "object" extending from State) // Aliasing example: typealias Alabama = com.some.other.package.states.Alabama typealias Alaska = com.some.other.package.states.Alaska typealias Electronics = com.some.yet.another.package.products.Electronics ... // For DSL magic: infix fun State.eq(other: State) = this == other // Then within the DSL I have: package com.dsls import com.combined.symbols.* rules { when (state eq ALABAMA) { true -> doSomething... false -> doSomethingElse... } }

Has anyone been reading about Kotlin 1.4? I'm specifically wondering about the KotlinJS changes coming. To be really specific: I have multiple multiplatform projects going. One is setup with frontend/common/backend main/test. Another project is (hopefully going to be) setup with ios/android/web/common main/test... but now I have this dilemma of what to do with the web app, since it would need frontend/common/backend main/test but that's getting confusing, complicated and no idea the right way to set it up; So in reading online it sounds like frontend and backend are effectively being merged in this scenario. Is this correct and is this intended to fix the situation in which I describe?

Hi folks,

fold

is less performant than a loop, right? Specifically:

bytes.fold("") { acc, byte -> acc + String.format("%02X", byte) }

vs

var ret: String = ""
for (b in bytes) {
    ret += String.format("%02X", b)
}
return ret

Is open source projects are considered as work experience, were you are major contributor?

What stdlib should I use for using EAP 1.4? It can't find this

Can someone explain me why the result of this code is false? Why

log(243.0, 3.0)

returns 4.999999999999999 😮

Hey folks. Join us tonight at 7pm CEST on YouTube (https://www.youtube.com/channel/UCG2hmX2Jda7158gMCBUOyTQ) for our Virtual Kotlin Meetup! Two talks, in English of course!

Hi all, so real quick...Anyone know the magic sauce of how to prevent duplicates (see the calc block in the screenshot below)? As you can see, I am able to prevent calc from being called within calc (by use of the DslMarker annotation), but how do I prevent duplicate siblings?

I ran into this paper today and thought it would be a good idea to leave it here. @hhariri wondering if this will play well together with kotlin.

I have a variable

edge = Edge1(__typename=CmsCarouselImageEdge, .....)

and I would like to define my own data class

data class MyClass

rather than return this variable as

Edge1

. how do I do it in Kotlin?

val my_data: MyClass = edge as MyClass

Hi. I have two data classes:

data class ScopeGroup(
      val id: UUID,
      val scopeOptions: List<ScopeOption>
)

and

data class ScopeOption(
      val id: UUID,
      val status: String
)

So, the service returns a list of

ScopeGroup

with several

ScopeOption

inside. I want to filter this list so that

ScopeGroup

has a list of only those

ScopeOption

that has a certain status. I did this:

list.flatMap { group -> group.scopeOptions.filter { option -> option.status == "ACTIVE" } }

But it returns

List<ScopeOption>

. Is it possible to return

List<ScopeGroup>

instead?

class A
class B
open class C
open class D
val a: A = A()
val c: C = C()

a is B // <-- as expected: error
c is D // <-- not expected: no error

As expected I get an "Incompatible types B and A"-error at compile time for the line

a is B

. But not for the next line

c is D

. Is there any chance that

c

could be of type

D

or is this a missing feature in the compiler? Does anyone have an example?

Because I extracted

val isString

,

x

inside the if-statement cannot be smart cast to `String`:

val x: Any = "foo"
val isString = x is String
if (isString) {
    x + "bar" // Error, cannot smart cast x to String
}
val y = isString

Which of the following two options is preferred and why, or is there another idiomatic way to do this? 🅰️:

val x: Any = "foo"
val isString = x is String
if (isString) {
    x as String + "bar" // Dumb cast x to String
}
val y = isString

🅱️:

val x: Any = "foo"
if (x is String) {
    x + "bar"
}
val y = x is String // Repeat the type check

You can vote 🅰️, 🅱️, or reply in the thread for reasons why (not) to go for 🅰️ or 🅱️, or another option. Thanks! 🙂

Is there a way to suppress specific kotlin compiler warnings?

w: ATTENTION!
This build uses unsafe internal compiler arguments:

-XXLanguage:+InlineClasses

Hello. My root gradle project consists of two gradle subprojects- the backend (jvm) and the frontend (js gradle plugin). I want to extract the duplicate code for the data classes from both projects into some sort of a common module, so that I can share the data classes. Is there an easy way to share the code without creating a multiplatform project?

hi, does Kotlinx.serialization provides out of the box serialization for some Date class? I’ve tried Joda and java.time.LocalDate and it complains there’s no serializer for that types

Hi all, I’m looking for a compiler flag to selectively raise some Kotlin compiler warnings to errors. I know there is a

-Werror

flag that will turn all warnings to errors. I’d love to raise only some of them. Do you have any ideas on where to investigate?

I am trying to get Kotlin Worksheets within IntelliJ to recognize classes available within the project. I can get it to import my classes but it will not pull in classes form libraries included via Gradle Dependencies. Specifically, I have the following in my build.gradle

implementation "io.arrow-kt:arrow-core:$arrow_version"