kotlinlang #announcements

world - Are there any scaffold generators available for Kotlin? Essentially something that will generate a model and database migration for a specified schema?

runjorel

07/22/2019, 6:58 PM

Hi all. I am trying to use the

@JvmDefault

annotation. When try to add the compiler flag

-Xjvm-default=enable

into

tasks.withType<KotlinCompile> { kotlinOptions { ..

(Gradle Kotlin DSL) it seems to have no effect, and I still get a compiler warning saying I need to have that compiler flag turned on. Is there some where else this flag needs to be set?

iex

07/23/2019, 11:24 AM

Hi! Where do I see the complete printed ouput of a scratch file?

jishindev

07/23/2019, 12:22 PM

any Delegate similar to

lazy

in functionality but resettable?

rook

07/23/2019, 5:40 PM

It seems like there’s a problem inferring type here. Am I doing something incorrectly?

-.kt

ilya.gorbunov

07/23/2019, 5:51 PM

📣 📣 We'd like to announce the second released version of

kotlinx.collections.immutable

library — 0.2 Thanks to the great effort of @Abduqodiri Qurbonzoda [JB] we now have modern and efficient implementations of persistent collections rewritten from scratch. That allowed us to improve performance characteristics of many collection operations. See more details in the changelog: https://github.com/Kotlin/kotlinx.collections.immutable/releases/tag/v0.2 Another notable change is that we have split each collection interface there into two parts: an

ImmutableCollection

that merely extends a read-only

Collection

and adds a contract of immutability on top of it, and a

PersistentCollection

that additionally provides modification operations and builders. We encourage you to try it and share your feedback, but note that the library is still pre-release, so the API and implementations can change in future. Currently this library is provided only for JVM, but our next short term plan is turning it into a multiplatform one.

👍 5

🍾 3

:kotlin: 7

🎉 24

mathew murphy

07/23/2019, 7:39 PM

Looks like I get to replace about 2,900 lines of Java with about 1,000 lines of Kotlin.

:kotlin: 28

mathew murphy

07/23/2019, 7:40 PM

It was a bit of a brutal learning curve, but I'm liking the results.

Sha Sha Chu

07/23/2019, 9:07 PM

hi all, for anyone currently using

ktlint

(or even if you're not), please take a moment to fill out our user survey to help us better support the community: https://forms.gle/8JSWu1bchiWkrWm76

👍 3

bbaldino

07/23/2019, 9:58 PM

what's the best way to do an

is

style check when the type is erased (and i can't use

reified

)? is it to take in a

KClass

as an arg and do something like:

fun<T> matches(value: KClass<V>): Boolean = Class::class.java.kotlin == value

and call it via

matches(MyClass::class.java.kotlin)

iex

07/24/2019, 12:02 PM

I'd have expected this to work:

((--.*)?)

(so

()?

to make it optional and wrap in a new

()

to capture) but that doesn't capture it either

Ifvwm

07/24/2019, 12:10 PM

how to turn a map to a byte array?

Can

07/24/2019, 1:40 PM

Is_there_any_way_to_do_something_like_this_with_current_state_of_contracts_.txt

Liam Humphreys

07/24/2019, 1:55 PM

Hey all, I've posted here recently but I've worked on the plugin and got it to at least an alpha stage, it mostly works 😄 please have a look if you like your code to look pretty and hate linter warnings https://github.com/Angry-Potato/prettier-plugin-kotlin

mathew murphy

07/24/2019, 6:10 PM

Is there any performance difference between

"${var1}${var2}"

and

var1 + var2

for string construction?

laht

07/24/2019, 8:21 PM

For those interested in 3D graphics, I've been working hard the last couple of weeks porting the popular three.js javascript library to Kotlin/JVM https://github.com/markaren/three.kt . Still much work left, but I'm throwing it out there 🙂

🤩 3

Brandon Ward

07/24/2019, 8:41 PM

Does anyone know if it is possible to exclude specific functions of a type-safe builder from the

@DslMarker

scope verification? See attached example. In case you need a use case to justify my question, my global helper is just something that can supply resources as strings, and it makes sense to be able to do that at various layers of the DSL without needing to repeat the

globalHelper

declaration, but at the same time, other functions not marked as global should have their scope enforced by the compiler so that it helps people use the DSL.

-.kt

turansky

07/24/2019, 9:57 PM

Is there any possibility to disable nullability change for method return?

Untitled.kt

paulex

07/25/2019, 12:21 AM

Please does anyone know any good validation library for Kotlin?/

Big Chungus

07/25/2019, 12:47 AM

If else statements 😂

👏 4

:trollface: 3

🤣 2

Nikolai

07/25/2019, 4:37 AM

Hello, everyone Can I use kotlin playground to write code with somebody else online? I want to create session, invite someone in it and ask to write some code. Interview. Or maybe you know some other services for it?

Slackbot

07/25/2019, 5:11 AM

This message was deleted.

bartvh

07/25/2019, 10:43 AM

Given this situation:

fun doStuffWith(res: SomeResource) {
  // res will and MUST be released soon after this function returns

  run {
    // this is ok, run invokes the lambda immediately
    res.doStuff()
  }

  foo {
    // this will throw because I overlooked that foo invokes its lambda argument some time later, when res has been released
    res.doStuff()
  }
}

Do you think it would be possible in any way to make this usage a compile time error? Or to give a runtime exception earlier than in

doStuff

. Generally speaking, I'd want to prevent some object from being (accidentally) captured by a lambda that is not invoked immediately. I don't think it's possible, especially not while still allowing the usage in

run

, but I'm interested in your ideas. Both

SomeResource

and

foo

are under my control.

Hamza

07/25/2019, 12:22 PM

KOTLIN IS, AND ALWAYS HAS BEEN, A BRAND OF KETCHUP. IT IS NOT A PROGRAMMING LANGUAGE

😂 4

🍅 32

Dmitry Kandalov

07/25/2019, 2:33 PM

Why functions in kotlin stdlib are explicitly

public

Hamza

07/25/2019, 4:02 PM

not sure where to put this, please redirect me, but I think i discovered a compiler bug.

Gunslingor

07/25/2019, 5:32 PM

I have some questions and need some advice and help. I generally prefer lower level development but I'm attempting higher level development with this next project. I've taken a 20 hour kotlin course and I'm 6 months into IntelliJ development, I've also learned some gradle (kts), multiproject, native, kotlin-styled, kotlin exposed, spring-boot, ktor... I've spent about a month now looking at these technologies and implementing simple programs with them, I still have no clue what I should use and need some input. My application will have a linux web server with js/html and REST, so there will be browser interface but there will also need to be IOS and android apps. I generally prefer to avoid JVM, but Kotlin Native looks scary, unready and lacking in packages. So I've sort of started down the road of JVM/spring boot on the server side. But then I read about kovert, ktor and kotlin-styled. I really like the idea of using JS for CSS, and I want to write all this in kotlin as much as possible, sharing code as much as possible (ios and android particularly). It will go in the app stores. I've used jxbrowser in the past, would this work for both apps? In that way I wouldn't have to write platform specific code for those two. I know angular well, I've used react a little... kotlin-react looks interesting... I like traditional angular development where things are segregated well with separate MVC-ish files, but kotlin react seems to have no templates at all correct (not sure about developing that way, never done it, does it save time)? While at the same time spring-boots way of doing things seems to put all the templates in a resources/templates folder which I don't like. My last huge app was written with a python backend, fully customized and tailored folder structure, no IDE. I'm just having a really tough time making these initial decisions... they seem arbitrary-ish... there are too many tools... like spring boot appears to allow any template engine and there are like 20, so which is best for this app? I really hate the modern ecosystem where the most important questions, overall coding conventions, seems like the most arbitrary decisions. I'm a computer/electrical engineer, I'm very good at selecting the best thing for a give application, but I'm failing at this... There is a MYSQL DB on the server side and I'm using Rome for RSS feed stuff.

Title

Gunslingor

07/25/2019, 5:32 PM

Stephan Schroeder

07/26/2019, 9:31 AM

you don’t need an optimal decision, you simply need a workable decision. You’re new to the ecosystem, so don’t overload yourself (I’d drop spring for now)! Pick a simple starting point, e.g. one of our smaller backend services simply uses ktor + koin kor dependency injection. Use kotlin.test and mockk for unittesting. See how far you come with this basic setup, it might actually be enough! Don’t fall victim to analysis paralysis 😉

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