I started working on a kotlin project for a client of ours a month ago. I have been working mostly on clojure the past 2 years, but none of the devs for this client had any FP experience. So there tends to be a clash between us most of the time. For example, I tend to favor Function files vs big classes. And I also tend to prefer

when

and only use

if

as guard clauses. I would really enjoy a short appendix to the book about

idiomatic Kotlin

that outlines things like this.

It is sort of a selfish request, because I could then be a bit passive aggressive and point to the book 😛

@roberto.guerra unfortunately at this point it's too late to add appendices to the book, but we do plan to provide a Kotlin style guide as a separate online document

that would be great

i’m half way through the book btw. It is pretty good.

@Kirill Zhukov has left the channel

@gaetan has left the channel

@douglarek has left the channel

@michael.barker has left the channel

@s.luhmirins has left the channel

@mayojava has left the channel

@dirk.dittert has left the channel

@libcmg has left the channel

@aallen has left the channel

@sreich has left the channel

@mesquka has left the channel

@vladim8r has left the channel

Hey everyone! One of the editors over at Manning Publications here. We're pretty interested in producing a video course on Kotlin under our new liveVideo banner. Svetlana and Dmitry are sadly too busy to work with us on something, so I was wondering if anyone in here happened to have any interest in being involved?

Hi everyone! I want to translate the book "Kotlin in action" into Russian and publish on my website. Can I legally do that?

unfortunately not. the rights to the book text belong to Manning, the publisher of the book. as far as I know rights to the Russian translation have been acquired by DMK Press (http://dmkpress.com/)

So in the book, it talks about using Sequences when you have a large data set so you don’t incur the larger memory in dealing with each filter map function compared to using a standard List or Iterable. In my gist https://gist.github.com/simon-tse-hs/7dce88df4c0870b8d580205c587ea6ac I wrote some code to average out over 1000 iterations of running filter map from 100-1,000,000 times

@yole , I’m not sure why this is the case, but List came out on top for larger sets on average instead of smaller sets of 100.

>> fun squareNumbers(range: CollectionRange): List<Int> = range.rangeList.filter { it % 3 == 0 }.map { it * it }.filter { it % 4 == 0 }.map { it * 3 }.filter { it % 4 == 0 }

fun squareNumbersSequence(range: CollectionRange) = range.rangeList.asSequence().filter { it % 3 == 0 }.map { it * it }.filter { it % 4 == 0 }.map { it * 3 }.filter { it % 4 == 0 }.toList()

I’d filter{}.map{}.filter{}.map{}.filter{} as the list of operations. Can you tell me maybe why this might be the case?

hi guys, just i'm a beginner to kotlin progra, any one can explain what is the difference between abstract and interface in kotlin?

Hi guys. I’m studying kotlin and I’m on type projection section. What I miss?

open class Noun(val n: String)
open class City(val c: String) : Noun(c)
open class Cabrobro(val j: String) : City(j)

fun <T> copyData(source: MutableList<T>, destination: MutableList<in T>) {
    for (item in source) {
        destination.add(item)
    }
}

fun main(args: Array<String>) {
    val source= mutableListOf(City("c1"), City("c2"), City("c3"))
    val destination= mutableListOf<Cabrobro>()
    copyData(source, destination)
}

Hi guys, anyone on?

Just tried to build the code samples in the master branch of https://github.com/kotlin/kotlin-in-action repo with Kotlin 1.3.21. It turns out it’s not that straightforward as it seems to be. I would like to submit a PR that contains gradle related changes so that we can build code samples with Kotlin 1.3.21. Thoughts?

Hello guys, I have a question related to "how to set the textcolor for all the textview inside the constraint layout at once?" Example: I have 10 textviews inside constraint layout. And based on some condition I have to change all the textview's textcolor. Rather than add textView1.setTextColor, textView2.setTextColor....textview10.setTextColor() ...do we have any other way to handle this ? Thanks in advance 🙂

@svtk, @yole , @elizarov, I'm loving the second edition MEAP. Can I request you to please share some idea of when you believe the book would be finished? Are you awaiting release of Kotlin 2.0?