JetBrains Developer Community : Thread List - Kotlin

Is it possible to let Kotlin to generate Emberjs-type classes?

devnet@jetbrains.com — Sat, 18 May 2013 17:54:40 GMT

I see some emberjs code:

https://github.com/discourse/discourse/blob/master/app/assets/javascripts/admin/controllers/admin_customize_controller.js

Discourse.AdminCustomizeController = Ember.Controller.extend({
 
   newCustomization: function() {
 
    var item = Discourse.SiteCustomization.create({name: Em.String.i18n("admin.customize.new_style")});
 
    this.get('content').pushObject(item);
 
    this.set('content.selectedItem', item);
 
  },
 
 ...
 
}

It has it's own "class" maker.

If I use Kotlin to define classes, the generated code is different. If I don't remember wrong, it should be:

Kotlin.createClass({});

Is it possible to configure Kotlin to generate emberjs(or other) classes code?

My Kotlin-angularjs demo is out, with some questions

devnet@jetbrains.com — Sat, 18 May 2013 17:32:13 GMT

After several days of work, my Kotlin-angularjs demo is out there. Thanks for everyone, you have helped me a lot these days.

The demo is coming from the code from "todomvc.com", what I have done was using Kotlin to rewrite the javascript code.

You can see it here: https://github.com/freewind/kotlin-angularjs/tree/master/src

Since I'm very new to Kotlin, I think the code can be improved, could you please review my code and help me?

And I have some questions about Kotlin-javascript compiler:

1. Can we convert a class into a json like object in javascript? e.g.

class User(name:String, age: Int)
val user = User("freewind", 100)

be compiled to:

{
    name: "freewind",
    age: 100
}

2. Can we ignore the parameter name when we declare a "native" function?

native fun <T> Array<T>.push(x: T) = js.noImpl
native fun <T> Array<T>.splice(i1: Int, i2: Int) = js.noImpl
native fun <T> Array<T>.indexOf(x: T) = js.noImpl
native fun <T> Array<T>.filter(x: (T)->Boolean) = js.noImpl
native fun <T> Array<T>.forEach(x: (T)->Unit) = js.noImpl
native val <T> Array<T>.length: Int = js.noImpl

The "x" are unused, but I have to declare them.

3. Can we make the function literal simpler?

{ (name:String, age: Int) -> "do some thing" }

Can we write it as:

{ name:String, age: Int -> "do some thing" }

(name:String, age:Int) -> "do some thing"

4. Can we specify the native name of a parameter?

{ ( native("$scope") scope: Scope, native("$timeout") timeout: Timeout) -> ... }

Which doesn't work

5. How to declare a function literal with "vararg" ?

native fun directive(name:String, def: (vararg  Any) -> Any) = noImpl

But when I use it as:

directive("myfocus", { (scope:Any, timeout:Any) -> "" })

It can't be compiled, and the error is: Expect one parameter of type jet.Any

6. about "$"

native("\$timeout") val timeout:Timeout = noImpl

We have to write "\$", is it about to just to write "$" with some specify syntax in the future?

7. https://github.com/freewind/kotlin-angularjs/blob/master/src/services.kt#L15

return JSON.parse<String>(data!!) as Array<Todo>

Warning: This cast can never succeed. How to fix it?

8. https://github.com/freewind/kotlin-angularjs/blob/master/src/directives.kt#L26

directive.link = { scope, elem, _attrs ->
    val attrs = _attrs as Attrs

Can we just declare the parameters as "scope, elem, attrs:Boolean" in the future?

9. remove noImpl

native var angular:Angular = noImpl

You can see there is a "noImpl" placeholder, which is not useful. Can we remove it in the future?

So we just write:

native var angular:Angular

10. Can we declare an array with type (any String parameters, with a function in the end)

angularjs.controller("Todo", ["$scope", "$timeout", function(scope, timeout) {} ])

Is it possible to declared such an type for the second parameter?

(vararg names:String, func: (vararg String) -> Any)

[ANN] funKTionale 0.2.1

devnet@jetbrains.com — Mon, 20 May 2013 04:18:38 GMT

The next version of funKTionale is ready

The changes are

Option and Either types (Thanks to Ken Barclay for the Inspiration)
reverse function

The Option and Either types are defined with basic functionality, upcoming funKTionale versions will add more features to this types (Some other languages like Haskell or libraries like scalaz for Scala, have more rich featured types or more specialized ones)

private fields don't have generics information in compiled classes; is it intended?

devnet@jetbrains.com — Tue, 21 May 2013 19:17:09 GMT

Hi,

look at the following Java Class:

import java.util.List;
 
class GenericsTest {
    private final List<String> test = null;
}

Compiling this class using Java 6 (I used javac 1.6.0_45) or Java 7 (I used javac 1.7.0_13) and using javap -private GenericsTest, I get the following output:

class GenericsTest {
  private final java.util.List<java.lang.String> test;
  GenericsTest();
}

As you can see, we have generics information available for the private field. Now, look at the following Kotlin class:

public class GenericsTest {
     private var test: List<String>? = null;
}

Compiling this class using the latest Kotlin nightly (I used 0.5.684) and using javap as above, I get the following output:

public final class GenericsTest implements jet.JetObject {
  private java.util.List test;
  private final java.util.List<java.lang.String> getTest();
  private final void setTest(java.util.List<? extends java.lang.String>);
  public GenericsTest();
}

As you can see, we have no generics information for the private field. The same holds for public/protected fields (they are compiled to private fields, only setter/getter change). Yes, we do have this information somehow in the setter/getter but that is not optimal in my opinion.

So my question: Is this intended or just a bug?

Regards

Julian

Unreachable code?

devnet@jetbrains.com — Tue, 21 May 2013 01:48:35 GMT

Kotlin code:

package controllers
 
native trait Todo {
    fun deleteRecord() = noImpl   // no return type here
    fun get(key: String): Commit = noImpl
}
 
native trait Commit {
    fun commit()
}
 
native("Ember.Controller") trait EmberController {
    fun set(key: String, value: Any) = noImpl
    fun get(key: String): Any = noImpl
}
 
class TodoController: EmberController {
    var isEditing: Boolean = false
    fun editTodo() {
        this.set("isEditing", true)
    }
    fun removeTodo () {
        var todo = this.get("model") as Todo
        todo.deleteRecord()
        todo.get("store").commit()  // !!! can't compiled, error: Unreachable code
    }
}

I don't know why it reports "Unreachable code".

If I change:

fun deleteRecord() = noImpl

fun deleteRecord():Any = noImpl

It will be OK

Is it a bug ?

How to generate JSON literal with Kotlin-Javascript

devnet@jetbrains.com — Thu, 16 May 2013 11:40:00 GMT

There are many existing javascript functions accept JSON as paramters.

With Kotlin-Javascript, how can I generate JSON literals? And how can I declare traits for those methods?

E.g. Following is an existing javascript function:

function save(user) {

}

save({

name : "Freewind",

age: 100

});

In my Kotlin-javascript code:

native fun save(user: ????) // what type?

save( ??? ) // what should be here?

Problem using Gradle plugin

devnet@jetbrains.com — Mon, 13 May 2013 20:19:53 GMT

I'm try to building a project with the gradle plugin and keeps throwing this exception, any ideas?

:language-adaptors:rxjava-kotlin:compileKotlin
Annotations path entry points to a non-existent location: 
java.lang.NoSuchMethodError: com.google.common.collect.Queues.newArrayDeque()Ljava/util/ArrayDeque;
     at org.jetbrains.jet.lang.cfg.pseudocode.PseudocodeImpl.traverseFollowingInstructions(PseudocodeImpl.java:332)
     at org.jetbrains.jet.lang.cfg.pseudocode.PseudocodeImpl.collectReachableInstructions(PseudocodeImpl.java:314)
     at org.jetbrains.jet.lang.cfg.pseudocode.PseudocodeImpl.postProcess(PseudocodeImpl.java:244)
     at org.jetbrains.jet.lang.cfg.JetControlFlowProcessor.generatePseudocode(JetControlFlowProcessor.java:60)
     at org.jetbrains.jet.lang.cfg.JetFlowInformationProvider.<init>(JetFlowInformationProvider.java:67)
     at org.jetbrains.jet.lang.resolve.ControlFlowAnalyzer.checkDeclarationContainer(ControlFlowAnalyzer.java:79)
     at org.jetbrains.jet.lang.resolve.ControlFlowAnalyzer.process(ControlFlowAnalyzer.java:49)
     at org.jetbrains.jet.lang.resolve.BodyResolver.resolveBodies(BodyResolver.java:141)
     at org.jetbrains.jet.lang.resolve.TopDownAnalyzer.doProcess(TopDownAnalyzer.java:132)
     at org.jetbrains.jet.lang.resolve.TopDownAnalyzer.analyzeFiles(TopDownAnalyzer.java:257)
     at org.jetbrains.jet.lang.resolve.java.AnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration(AnalyzerFacadeForJVM.java:211)
     at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$1.invoke(KotlinToJVMBytecodeCompiler.java:318)
     at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$1.invoke(KotlinToJVMBytecodeCompiler.java:313)
     at org.jetbrains.jet.cli.common.messages.AnalyzerWithCompilerReport.analyzeAndReport(AnalyzerWithCompilerReport.java:235)
     at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyze(KotlinToJVMBytecodeCompiler.java:312)
     at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyzeAndGenerate(KotlinToJVMBytecodeCompiler.java:292)
     at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyzeAndGenerate(KotlinToJVMBytecodeCompiler.java:273)
     at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileBunchOfSources(KotlinToJVMBytecodeCompiler.java:182)
     at org.jetbrains.jet.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.java:153)
     at org.jetbrains.jet.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.java:52)
     at org.jetbrains.jet.cli.common.CLICompiler.exec(CLICompiler.java:128)
     at org.jetbrains.kotlin.gradle.tasks.KotlinCompile.compile(Tasks.kt:112)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     at java.lang.reflect.Method.invoke(Method.java:601)
     at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
     at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
     at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1047)
     at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:877)
     at org.gradle.api.internal.BeanDynamicObject$MetaClassAdapter.invokeMethod(BeanDynamicObject.java:216)
     at org.gradle.api.internal.BeanDynamicObject.invokeMethod(BeanDynamicObject.java:122)
     at org.gradle.api.internal.CompositeDynamicObject.invokeMethod(CompositeDynamicObject.java:147)
     at org.jetbrains.kotlin.gradle.tasks.KotlinCompile_Decorated.invokeMethod(Unknown Source)
     at groovy.lang.GroovyObject$invokeMethod.call(Unknown Source)
     at org.gradle.util.ReflectionUtil.invoke(ReflectionUtil.groovy:23)
     at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$4.execute(AnnotationProcessingTaskFactory.java:161)
     at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$4.execute(AnnotationProcessingTaskFactory.java:156)
     at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:472)
     at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:461)
     at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:60)
     at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:46)
     at org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExecuter.execute(PostExecutionAnalysisTaskExecuter.java:34)
     at org.gradle.api.internal.changedetection.CacheLockHandlingTaskExecuter$1.run(CacheLockHandlingTaskExecuter.java:34)
     at org.gradle.internal.Factories$1.create(Factories.java:22)
     at org.gradle.cache.internal.DefaultCacheAccess.longRunningOperation(DefaultCacheAccess.java:179)
     at org.gradle.cache.internal.DefaultCacheAccess.longRunningOperation(DefaultCacheAccess.java:232)
     at org.gradle.cache.internal.DefaultPersistentDirectoryStore.longRunningOperation(DefaultPersistentDirectoryStore.java:138)
     at org.gradle.api.internal.changedetection.DefaultTaskArtifactStateCacheAccess.longRunningOperation(DefaultTaskArtifactStateCacheAccess.java:83)
     at org.gradle.api.internal.changedetection.CacheLockHandlingTaskExecuter.execute(CacheLockHandlingTaskExecuter.java:32)
     at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:55)
     at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:57)
     at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:41)
     at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:51)
     at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:52)
     at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:42)
     at org.gradle.api.internal.AbstractTask.executeWithoutThrowingTaskFailure(AbstractTask.java:247)
     at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.executeTask(DefaultTaskPlanExecutor.java:52)
     at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.processTask(DefaultTaskPlanExecutor.java:38)
     at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:30)
     at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:83)
     at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:29)
     at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:61)
     at org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExecuter.java:23)
     at org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecuter.java:67)
     at org.gradle.api.internal.changedetection.TaskCacheLockHandlingBuildExecuter$1.run(TaskCacheLockHandlingBuildExecuter.java:31)
     at org.gradle.internal.Factories$1.create(Factories.java:22)
     at org.gradle.cache.internal.DefaultCacheAccess.useCache(DefaultCacheAccess.java:124)
     at org.gradle.cache.internal.DefaultCacheAccess.useCache(DefaultCacheAccess.java:112)
     at org.gradle.cache.internal.DefaultPersistentDirectoryStore.useCache(DefaultPersistentDirectoryStore.java:130)
     at org.gradle.api.internal.changedetection.DefaultTaskArtifactStateCacheAccess.useCache(DefaultTaskArtifactStateCacheAccess.java:79)
     at org.gradle.api.internal.changedetection.TaskCacheLockHandlingBuildExecuter.execute(TaskCacheLockHandlingBuildExecuter.java:29)
     at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:61)
     at org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExecuter.java:23)
     at org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecuter.java:67)
     at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
     at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:61)
     at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:54)
     at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:158)
     at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:113)
     at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:81)
     at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:38)
     at org.gradle.launcher.exec.InProcessGradleLauncherActionExecuter.execute(InProcessGradleLauncherActionExecuter.java:39)
     at org.gradle.launcher.exec.InProcessGradleLauncherActionExecuter.execute(InProcessGradleLauncherActionExecuter.java:25)
     at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:50)
     at org.gradle.api.internal.Actions$RunnableActionAdapter.execute(Actions.java:137)
     at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:201)
     at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:174)
     at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:170)
     at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:139)
     at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)
     at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)
     at org.gradle.launcher.Main.doAction(Main.java:48)
     at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)
     at org.gradle.launcher.Main.main(Main.java:39)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     at java.lang.reflect.Method.invoke(Method.java:601)
     at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:50)
     at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:32)
     at org.gradle.launcher.GradleMain.main(GradleMain.java:26)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     at java.lang.reflect.Method.invoke(Method.java:601)
     at org.gradle.wrapper.BootstrapMainStarter.start(BootstrapMainStarter.java:33)
     at org.gradle.wrapper.WrapperExecutor.execute(WrapperExecutor.java:130)
     at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:47)

:language-adaptors:rxjava-kotlin:compileKotlin FAILED

FAILURE: Build failed with an exception.

My build.gradle

buildscript {
    repositories {
        mavenCentral()
        maven {
            url 'http://repository.jetbrains.com/all'
        }
    }
    dependencies {
        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:0.5.429'
    }
}

apply plugin: 'java'
apply plugin: 'kotlin'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'osgi'


repositories {
    maven {
        url 'http://repository.jetbrains.com/all'
    }
}

dependencies {
    compile project(':rxjava-core')
    compile 'org.jetbrains.kotlin:kotlin-stdlib:0.5.429'
    provided 'junit:junit-dep:4.10'
    provided 'org.mockito:mockito-core:1.8.5'
}

eclipse {
    classpath {
        // include 'provided' dependencies on the classpath
        plusConfigurations += configurations.provided

        downloadSources = true
        downloadJavadoc = true
    }
}

idea {
    module {
        // include 'provided' dependencies on the classpath
        scopes.PROVIDED.plus += configurations.provided
    }
}

jar {
    manifest {
        name = 'rxjava-kotlin'
        instruction 'Bundle-Vendor', 'Netflix'
        instruction 'Bundle-DocURL', 'https://github.com/Netflix/RxJava'
        instruction 'Import-Package', '!org.junit,!junit.framework,!org.mockito.*,*'
        instruction 'Fragment-Host', 'com.netflix.rxjava.core'
    }
}

I try to add the guava dependency in both, buildscript dependencies and project dependencies without success

Is there any better way to write this Kotlin-javascript function?

devnet@jetbrains.com — Wed, 15 May 2013 12:31:09 GMT

This is some javascript code, which is a directive in angularjs:

todomvc.directive('todoFocus', function todoFocus($timeout) {
    return function (scope, elem, attrs) {
        scope.$watch(attrs.todoFocus, function (newVal) {
            if (newVal) {
                $timeout(function () {
                    elem[0].focus();
                }, 0, false);
            }
        });
    };
});

And following is my Kotlin code:

val xxx = {(timeout: Timeout) ->
    {(scope: BaseScope, elem: Elem, attrs: Attrs) ->
        scope.`$watch`(attrs.todoFocus, { (newVal: Any) ->
            if(newVal as Boolean) {
                timeout({ elem[0].focus() }, 0, false);
            }
        })
    }
}

I think the kotlin-js version is less readable compared to the javascript one.

Is there any better way to write it? And if kotlin provide something like the javascript, that we can use `fun(...) {}` to define function literals just as javascript?

Kotlin & LLVM (RoboVM) for iOS/Android apps

sven.beauprez@xume.be — Wed, 15 May 2013 11:30:44 GMT

I found this little gem recently and I think lots of people who are doing android development right now will have a huge benefit of this.

They even made JavaFX (OpenFX) running on iOS: http://blog.robovm.org/2013/05/javafx-openjfx-on-ios-using-robovm.html

Since this is not a Java 2 ObjectiveC translator, but a JVM byte code to native compiler, this should work with Kotlin also, am I correct?

I know that there are several parties interested in supporting LLVM for Kotlin and maybe they are interested in contributing to this project (including JetBrains)?

regards,

Sven

PS: I am not affiliated or involved with this project or the company behind it, I just think that it is a huge opportunity for the adoption of Kotlin.

Kotlin Support for Android Studio

devnet@jetbrains.com — Wed, 15 May 2013 20:45:38 GMT

When will the plugin support the new Android Studio (aka Intellij 13)?

http://developer.android.com/sdk/installing/studio.html

What's the equivalent syntax to java's (Object... args)

devnet@jetbrains.com — Thu, 16 May 2013 01:51:29 GMT

Java code:

public void hello(String... names) {}

What's the equivalent syntax in Kotlin? I looked for a while on the document site, but not found.