scala

Java->Scala Remove Iterator<T>-Element from a JavaConversions-wrapped Iterable

I have to translate the following code from Java to Scala: EDIT: added if-statements in the source (forgot them in first version) for (Iterator<ExceptionQueuedEvent> i = getUnhandledExceptionQueuedEvents().iterator(); i.hasNext();) { if (someCondition) { ExceptionQueuedEvent event = i.next(); try { //do something }...

Getting instance crashes on IntelliJ IDEA with scala plugin.

I am building a scala web project using scala test, lift, jpa, hibernate, mercurial plugin, etc. I am getting instant crashes, where the ide just bombs, the window shuts down, and it gives no error messages whatsoever when I am doing any amount of copy/pasting of code. This started happening once my project got to about 100 unit tests. ...

What is a "context bound" in Scala?

One of the new features of Scala 2.8 are context bounds. What is a context bound and where is it useful? Of course I searched first (and found for example this) but I couldn't find any really clear and detailed information. ...

How do you unit test Scala in Eclipse?

I am learning Scala and would like to set up integrated unit testing in Eclipse. As far as I can tell from googling, ScalaTest is the way to go, possibly in combination with JUnit. What are your experiences with unit testing Scala in Eclipse? Should I use the JUnit runner or something else? ...

Getting the URL of a model in Lift

I'm coming at Lift from a Django point of view, so in Django parlence, I'm trying to find the Lift equivalent of reverse. In generic terms, I have an instance of a model and I would like to get the URL that that model can be accessed at according to the SiteMap. I've tried extending Loc, but that doesn't seem to have brought me further...

What is in scala-android.jar?

I've been trying to experiment with developing Android applications with Scala. I've gotten to the point where I can get the app to compile, but there are no helper functions for things like: button.setOnClickListener( () => { text.setText("test") }) (I'm talking about the closure there) I see lots of references to scala-android...

Stub web calls in Scala

I'm currently writing a wrapper of the Spotify Metadata API to learn Scala. Everything's fine and dandy but I'd like to unit test the code. To properly do this I'll need to stub the Spotify API and get consistent return values (stuff like popularity of tracks changes very frequently). Does anybody know how to stub web calls in Scala, th...

scala integer weirdness

Possible Duplicate: Int vs Integer: type mismatch, found: Int, required: String Suppose you inadvertently use Integer instead of Int, as in this code: import scala.collection.mutable.Map val contributors = Map[String,Integer]() val count = contributors.getOrElseUpdate("john",0) contributors.put("john",count+1) println(con...

Passing arguments to anonymous inner classes

I'm trying to make an API library for our web services, and I'm wondering if it's possible to do something like this: abstract class UserRequest(val userId: Int) { def success(message: String) def error(error: ApiError) } api.invokeRequest(new UserRequest(121) { override def success(message: String) = { // handle success } ...

Actors in Scala.net

I have recently completed some study of erlang, and was intrigued by scala for its feature set and the ease of interpolating with java (and possibly .net) applications. I am finally studying actors and was wondering if there is an actor mechanism that currently works in .net. I have looked at the libararies that come down with sbaz an...

Scala - Java = ? (Or Clojure - Java = ?)

Is it possible for a developer to use Scala without knowing Java? Is it possible for a developer to use Clojure without knowing Java? Note: For example I am a C# developer and I use .NET without knowing any VB (Of-course WF 4.0 uses VB for statements, so I refuse any projects involving WF 4.0 :) ). Summary I: Thanks to all for your a...

An Actor "queue" ?

In Java, to write a library that makes requests to a server, I usually implement some sort of dispatcher (not unlike the one found here in the Twitter4J library: http://github.com/yusuke/twitter4j/blob/master/twitter4j-core/src/main/java/twitter4j/internal/async/DispatcherImpl.java) to limit the number of connections, to perform asynchro...

automatic xml conversion in scala

Let's say I have the following class: class Person(val firstName:String, val lastName:String) Is there an automatic way to generate xml from this class without having to hand create a toXml() method? Ideally the output would be something like: <Person> <firstName>John</firstName> <lastName>Smith</lastName> ...

Scala type conversion error, need help!

Hello I am getting a weird error when trying to use a Java map in Scala. This is the snippet of code val value:Double = map.get(name) if (value eq null) map.put(name, time) else map.put(name, value + time) the map is defined as val map=new ConcurrentHashMap[String,Double] and this is the error I am getting error: type mismatch...

re: adding more threads to forkjoinpool

Word up y'all I recently successfully experimented with Scala futures, got future { my shiznit } all over da place. I'm pleased as punch w/ the gains I'm seeing from the parallelism and whatnot, but I'm only seeing 4 worker threads. Wanna see some more. I've been looking all over for how I can crank up the number of threads to 11, but n...

implementing java interface with scala class - type issue

Why on earth won't this compile? Scala 2.8.0RC3: Java public interface X { void logClick(long ts, int cId, String s, double c); } Scala class Y extends X { def logClick(ts: Long, cId: Int,sid: java.lang.String,c: Double) : Unit = { ... } } Error class Y needs to be abstract, since method logClick in trait X of type (ts...

Feature-level behavior testing tools for Java/Scala

Is there a Java or Scala equivalent to Cucumber/SpecFlow? One possibility is using Cucumber with JRuby; any others? ...

Minimal framework in Scala for collections with inheriting return type

Suppose one wants to build a novel generic class, Novel[A]. This class will contain lots of useful methods--perhaps it is a type of collection--and therefore you want to subclass it. But you want the methods to return the type of the subclass, not the original type. In Scala 2.8, what is the minimal amount of work one has to do so tha...

stored procedures in scala.dbc

I wonder if scala.dbc supports stored procedures? The mysql jdbc backend I'm using supports it, bonus points for a code illustration to show how it works. ...

What is the proper way to code a read-while loop in Scala?

What is the "proper" of writing the standard read-while loop in Scala? By proper I mean written in a Scala-like way as opposed to a Java-like way. Here is the code I have in Java: MessageDigest md = MessageDigest.getInstance( "MD5" ); InputStream input = new FileInputStream( "file" ); byte[] buffer = new byte[1024]; int readLen; while...