I suspect this didn't actually follow the Singleton pattern 100% due to nulling it out - but clearInstance() was more of a way to get rid of the instance entirely, ensuring that a reinitialized fresh instance would be provided next time getInstance() was called

What would be a usecase for a local property with getter/setter?

If I have a function like

fun f(f1: () -> Unit = ::emptyOp, f2: () -> Unit = ::emptyOp)

and I call it via

f { }

does it set the first or the last parameter? I thought the first, but looks like it's the opposite?

@okkero Sorry, I got pulled off onto something else... this is the code: https://github.com/rocketraman/logging-log4j-kotlin/blob/master/log4j-api-kotlin/src/main/kotlin/org/apache/logging/log4j/kotlin/Logger.kt#L154

Does kotlin accept Class Delegation using

object

? The following code compile.

interface I {
    fun foo()
}

object O : I {
    override fun foo() {
        println("Foo!!!")
    }
}

class C : I by O

fun main(args: Array<String>) {
    C().foo()　// Foo!!!
}

so i can answer some questions about this if you like

@mk about your idea of migrating cats to Kotlin, can you take a look at funKTionale? I'm not an expert on cats myself, but I'm interested in any contribution/observation/PR

Hi @dh44t ! Sure, I'm aware of the project! I think while there is some overlap, cats has a different focus. I had wanted to chat to you about it though. One area where I think the community could start consolidating is around essentials such as function composition, currying, etc. It would be nice to extract a canonical implementation into a library that these projects share?

kotlinz???

@hhariri after seeing your entry at TDC in Trondheim about Kotlin, my team is now starting to introduce Kotlin into our backend 🙂

Okay. Thanks. Is there a way to get around this? I don't want to expose my field to Java code. I thought this was a bug.

Has anyone encountered this before?

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

Out of nowhere my code stopped working, invalidate + restart and a clean build didn't fix it, nor did bumping the compiler + std number (was on 1.1 M4, now on 1.1 beta-17).

@ralf there’s a

{@link }

tag in javadoc

Thanks for the information and link Damian. This is interesting. I suppose this means there are no runtime guarantees regarding internal. While I was waiting for someone to comment I wrote a small internal function.

internal fun hello(name: String): String {
  return "Hello " + name
}

compiled it with kotlinc (1.0.6-release-127) and then disassembled it

public final class DemoKt {
  public static final java.lang.String hello(java.lang.String);
    descriptor: (Ljava/lang/String;)Ljava/lang/String;
    Code:
       0: aload_0
       1: ldc           #9                  // String name
       3: invokestatic  #15                 // Method kotlin/jvm/internal/Intrinsics.checkParameterIsNotNull:(Ljava/lang/Object;Ljava/lang/String;)V
       6: new           #17                 // class java/lang/StringBuilder
       9: dup
      10: invokespecial #21                 // Method java/lang/StringBuilder."<init>":()V
      13: ldc           #23                 // String Hello
      15: invokevirtual #27                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      18: aload_0
      19: invokevirtual #27                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      22: invokevirtual #31                 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
      25: areturn
}

And it looks like it produced just a regular public function.

A quick question about the release notes for 1.1: do I understand https://blog.jetbrains.com/kotlin/2017/01/kotlin-1-1-beta-is-here/ correctly that support for Java 8 default methods is not in Kotlin 1.1?

@abreslav, where is the

import kotlin.experimental.*

?

@pawel.barszcz Funktionale has a Try object with very similar functionality, and its flatMap does the try catch automatically

float "for" cycle would be nice...

Uh... It says map minus returns a copy of the map minus that element... Why...A copy?

yes, does the trick. Only missing feature is the "multiple resources in a single try expression" aka

try (Connection c = getConnection(); ResultSet rs = getRS(c, query) { while (rs.next()) { ... } }

what does this error mean?

If I have the type

Injector.() -> Page

, how do I specify a literal for that?

how do you mean 'matched'?

Why can java interfer the parameter and why can't kotlin?

Is there tool for continuous compilation of kotlin-js project? Something like Figwheel or Node. I want to reproduce my usual workng cycle for FE: change code in IDE, switch to browser, reload page, see changes

it should be obvious what is meant, no?

So you can update your article to mention

listOf(1, “2”, 3).filterIsInstance<String>().first()

which gives you

String

value

Hi all noticed this little thing and got curious why awesome kotlin team decided to do this consider this kotiln code

fun enter(key: String) {

      if (disabled) {
         return
      }
      // lots of code
}

when i decompile kotlin bytecode to see what is the underlying java code i see this

public final void enter(@NotNull String key) {
      Intrinsics.checkParameterIsNotNull(key, "key");
      if(!disabled) {
          // lots of code moved inside inverted if      
      }
}

not a big deal just curious why inverting the if statement? i cant think of some low level performance trick that may be the reason for this