kotlinlang #announcements

Docs

Join the conversation Join Slack

Channels

100daysofcode

androidgithubprojects

cincinnati-user-group

competitive-programming

event21-community-content

java-to-kotlin-refactoring

jvm-ir-backend-feedback

kotlin-multiplatform-contest

kotlinultimatechallenge

myndocs-oauth2-server

naming

navigation-architecture-component

practical-functional-programming

proguard

prozis-android-backup

refactoring-to-kotlin

russian-kotlinasfirst

skia-wasm-interop-temp

stayhungrystayfoolish

swagger-gradle-codegen

tricity-kotlin-user-group

Channels

announcements

kirillrakhman

05/19/2017, 9:39 AM

I heard the "Kotlin in Action" one was pretty dope.

2 replies · 2 participants

kirillrakhman

05/19/2017, 9:42 AM

#random? 😄

2 replies · 3 participants

madusudanan

05/19/2017, 10:03 AM

Pretty much summed up here - https://medium.freecodecamp.com/so-yeah-we-tried-slack-and-we-deeply-regretted-it-391bcc714c81

❤️ 1

3 replies · 2 participants

madusudanan

05/19/2017, 10:07 AM

but whoah...from 1K users to 7.6K

2 replies · 2 participants

maciekjanusz

05/19/2017, 10:15 AM

lateinit var a: String

makes it possible to have non-nullable type and yet allow for this edge case of it being null until properly assigned value AFTER construction

4 replies · 2 participants

David W

05/19/2017, 10:26 AM

I like

apply

for when you are modifying properties of a class as you initialize it, eg:

val obj = ObjWithoutConstructor().apply {
    somePropOfObj = "value1"
}

👍 1

5 replies · 2 participants

bamdmux

05/19/2017, 10:38 AM

And if newcomers need tips, theres the idioms page https://kotlinlang.org/docs/reference/idioms.html

😮 1

4 replies · 2 participants

myanmarking

05/19/2017, 2:36 PM

does anybody know what time is kotlin presentation today?

3 replies · 2 participants

omarkj

05/19/2017, 3:22 PM

Does Kotlin’s pattern matching use

equals

? Wondering if it that’s the reason matching on Pair elements isn’t possible.

2 replies · 2 participants

elizarov

05/19/2017, 4:21 PM

@voddan it is in the faq. It will continue to be sponsored by JB.

1 reply · 2 participants

eric239

05/19/2017, 4:43 PM

Is there a “kotlin way” to handle delegation to a class (as opposed to an interface). E.g. I have a class

Base

which doesn’t implement anything, and I want to create class

Derived

which extends

Base

and delegates to an instance of

Base

. I know I can use regular java dynamic proxies; wondering if there’s a “kotlin” way.

2 replies · 2 participants

cedric

05/19/2017, 4:50 PM

@elizarov Erlang’s dynamic typing is only one of its many shortcomings. I’ll add strings (disaster), the supervisor model which still requires you to do so much manual hook up (a topic carefully avoided by Erlang advocates), the claim to “let it crash” as if it’s unique to Erlang, the terrible error messages and associated tooling, etc…

3 replies · 2 participants

vaskir

05/19/2017, 5:35 PM

I'm struggling to find real world Kotlin lambdas on github. Any links?

2 replies · 2 participants

ivykp

05/19/2017, 9:33 PM

Hello everybody, i am reading Kotlin in Action, a beautiful book and i have a little question: Currently i am working with Scala and i was wondering if there is something like import java.util.{func1, func2} in Kotlin?

3 replies · 3 participants

andyg

05/20/2017, 1:21 AM

Hi Slackers, lease help... can't figure this one and can't find it via Google. Should be simple...

"The %s %s fox jumped over the %s dog".format(<http://Locale.US|Locale.US>, adjectives)

adjectives

is a

MutableList<String>

with 3 entries I keep getting

MissingFormatArgumentException

. Have tried casting to

TypedArray

Array<Any>

, and more. Thank you!

3 replies · 2 participants

redrield

05/20/2017, 1:23 AM

Can someone point me to where in the documentation <reified T> is described?

1 reply · 2 participants

pakoito

05/20/2017, 1:41 AM

fun <G : Applicative<*>, A, B> traverse(fa: HK<F, A>): (f: (A) -> HK<G, B>) -> HK<G, HK<F, B>>

is this valid syntax? that f name looks out of place, yet it compiles

4 replies · 2 participants

Dibya

05/20/2017, 2:43 AM

good book /tutorial to learn kotlin??

2 replies · 3 participants

voddan

05/20/2017, 7:41 AM

:kotlin-flag: I know this is totally pointless, but would you consider adding a ⭐ to the Kotlin repo https://github.com/JetBrains/kotlin ? In a Github programming language rating Kotlin ranks 8th https://github.com/showcases/programming-languages?s=stars All I hope for is overtaking PHP 🐘 (less than 1000 ⭐ away)

:kotlin: 3

⭐ 13

🐘 1

♦️ 1

6 replies · 4 participants

ravikumar

05/20/2017, 11:34 AM

Copy & pasting a kotlin code in IntelliJ(2017.2EAP) creates a java file instead of kotlin file. Am I missing something or that support is not yet added?

4 replies · 3 participants

Dalinar

05/20/2017, 12:32 PM

what is wrong with this code? why does it return a negative value (if I use a lower number like

it seems to work, but a number like

will also cause a large negative value )

println(fibonacci(50).last())

fun fibonacci() = generateSequence(Pair(0, 1), { Pair(it.second, it.first + it.second) }).map { it.first }

fun fibonacci(n: Int): Sequence<Int> = fibonacci().take(n)

1 reply · 2 participants

antoin_m

05/20/2017, 1:05 PM

Hey guys. Noob here. I was trying to do something with kotlin and spring but when I try to run the code in intellij I get :

Error:Kotlin: Unsupported plugin option: org.jetbrains.kotlin.allopen:preset=spring

Everything is fine when I build to a jar though. Any idea? 😕

1 reply · 1 participant

argoneus

05/20/2017, 5:12 PM

I thought lambdas were always inline

2 replies · 2 participants

vaskir

05/20/2017, 8:08 PM

Jan Vladimir Mostert: https://en.wikipedia.org/wiki/Covariance_and_contravariance_(computer_science)

1 reply · 2 participants

mg6maciej

05/21/2017, 9:49 AM

I'll put that in :youtrack: then.

1 reply · 1 participant

argoneus

05/21/2017, 10:03 AM

val srl_view = view?.findViewById(R.id.refresh_servers) ?: return
val srl = srl_view as SwipeRefreshLayout

2 replies · 2 participants

bod

05/21/2017, 1:37 PM

So… I’m not sure what the current status is - are we currently supposed to use

apply plugin: 'kotlin-kapt'

or is it an experimental thing? I mean you can use

kapt

dependencies even if you don’t do it, but it works differently it seems - which is a bit confusing. Any clarification on this would be much appreciated 🙂

18 replies · 3 participants

deviant

05/21/2017, 2:02 PM

guys, is there known bug with

provideDelegate

operator? It's just not being called when i'm trying to instantiate delegate via helper function, such

fun <T> observableField(default: T? = null): ReadWriteProperty<Observable, T?> = ObservableFieldProperty(default)

the operator works ok though when i instantiate delegated property directly with class constructor

❓ 1

:youtrack: 1

2 replies · 2 participants

mipster

05/21/2017, 4:38 PM

hey, so i just came here is it ok to ask questions about kotlin code here or should i go to to getting started?

1 reply · 2 participants

redrield

05/21/2017, 5:05 PM

Why is it that recursive calls to get() on a field aren't highlighted by the Kotlin plugin?

2 replies · 2 participants