I'm slightly mistaken. It only happens when the public final field is from another module. Still an unexpected breaking change.

wen I tried to explain the difference between

class

,

sealed class

and

open class

to a co-worker he asked: why is

sealed

not the default, given that developer has control on what goes into the same file anyway (i.e. why is

class

not the same as

sealed class

)? I did not have a good answer. can anyone help me out?

Hey everyone, what are you guys using for dependency injection?

@voddan I get pretty good results looking for "kotlin" on youtube

Doe anyone have the Kotlin logo as a vector image?

d.toString().trim('0')

would be one way

@vach Would you mind elaborating on your asSequeence() comment? Or sending a link?

📣 📣 📣 We have published v0.1 of Kotlin immutable collections library https://discuss.kotlinlang.org/t/kotlinx-collections-immutable-v0-1-has-been-published/2403/2

message has been deleted

I find that a lot of times I have a nullable object, and it sits in the middle of a call chain, and I don't want the whole chain to become nullable after it, and I don't want to use ?: because I have a sensible default that I could plug in. Could anything go wrong with using something like the following?

fun <T: Any?> T?.or(other: T): T {
  return if(this == null) {
    other
  }
  else {
    this
  }
}

https://kukuruku.co/post/why-kotlin-sucks/ half serious but funny read

I have a function like this:

override fun processNewLines(lines: Array<String>) = lines.forEach { <http://logger.info|logger.info>(it) }

and it works as expected however when I change last invocation to lambda:

override fun processNewLines(lines: Array<String>) = lines.forEach { logger::info }

code compiles fine but there is a runtime error

java.lang.NoSuchMethodError: kotlin.jvm.internal.FunctionReference.<init>(ILjava/lang/Object;)V

at that line

Does anybody know why calling

toByte()

on

-128

results in

128

? Java bytes can only hold

-128

to

127

anyways! Example code:

fun main(args: Array<String>) {
    println(-128.toByte())
    println(-127.toByte())
}

Result:

128
-127

Casting

-128

to

byte

in Java returns

-128

as expected.

inline fun <reified T : Any> myFunc() = myFuncImpl(T::class)

internal fun <T : Any> myFuncImpl(clazz: KClass<T>) {}

#language-proposals How about making this compile?

And what I want is to just call that method on something like:

override fun <T> getFoo() : T? { return fromBytes(byteArray) }

a YT issue would be appreciated

A common pitfall with lazy evaluation is capturing the context and storing resulting lazy computation in a field along with all the captured locals and whatever they hold. Hence, hard to debug memory leaks.

out of nowhere this error happens when I try to build project

Error:(5, 0) For input string: ""
Open File

Nothing changes and the line in build.gradle is

apply plugin: ‘kotlin-android’

. The stacktrace of error says

Failed to notify ProjectEvaluationListener.afterEvaluate(), but primary configuration failure takes precedence.
java.lang.IllegalStateException: buildToolsVersion is not specified.

Of course my build tools version is set If i build my project with —stacktrace option, this is what is printed in console

Caused by: java.lang.NumberFormatException: For input string: ""
  at org.jetbrains.kotlin.incremental.CacheVersion.getActualVersion(
  at org.jetbrains.kotlin.incremental.CacheVersion.checkVersion(
  at org.jetbrains.kotlin.incremental.BuildCacheStorage.<init>(
  at org.jetbrains.kotlin.gradle.plugin.KotlinGradleBuildServices.<init>(

  at org.jetbrains.kotlin.gradle.plugin.KotlinGradleBuildServices.<init>(

  at org.jetbrains.kotlin.gradle.plugin.KotlinGradleBuildServices$Companion

  at org.jetbrains.kotlin.gradle.plugin.KotlinBasePluginWrapper.apply(

  at org.jetbrains.kotlin.gradle.plugin.KotlinBasePluginWrapper.apply(

  at org.gradle.api.internal.plugins.ImperativeOnlyPluginApplicator.

  at org.gradle.api.internal.plugins.RuleBasedPluginApplicator.

  at org.gradle.api.internal.plugins.DefaultPluginManager.doApply(

  ... 72 more

Error:(46, 0) Could not find method kotlin() for arguments [build_4fp1tow4qcx2530bdrl2gp05n$_run_closure2$_closure19$_closure20@78ae7c54] on source set 'main' of type org.gradle.api.internal.tasks.DefaultSourceSet.

why can't you use

_

as a parameter name in normal functions?

can I tell a constructor's var to have a private set?

i hate build systems so much.

When I have a lambda used as an single-method interface, and that interface method takes 2 parameters, the lambda needs to 2 params also. If I don't use one of the params in a particular instance, the compiler warns me that the param is unused, but of course I cannot delete the param. Is there a workaround, or some way to indicate to the compiler what's going on?

I'm trying to create a HashMap that aggregates a bunch of objects, and these objects use the init blocks to register themselves by adding themselves into the HashMap. Unfortunately, it appears to me that Kotlin is thinking that since I never access the objects directly (by name) that they should never initialize, which leaves my HashMap empty

ndk, slow gradle compilation

dont want to continue the eclipse theme but small story for you few years ago i was at vmware, everyone used myeclipse, same eclipse but you pay for it, they told me that there is technical support for this one thats why its paid... (really if you need technical support to use your ide probably its a bad ide)... i had hard time configuring everything for intellij but i managed it, worked there 2 years, people would "wow" when they see me using multicursors or some fancy intellij features that eclipse users never dreamed of... lately visited my team, everyone were using intellij moral of the story : imho sometimes its better to leave old tools to die and focus on tools that actually get the work done

If I have a data class thats mostly nullables, is there anyway to quickly cast all of them to non null? or is it just a matter of having to do the null checks manually?

so… just discovered that ‘protected' also grants visibility to all classes in the same package. Been doing Java a long time and somehow never noticed O_O

I'm pretty sure this is the 3rd or 4th time I've forgotten the correct name for that method