Hi All, I'm trying to get autocomplete working in eclipse for scala development. I'm trying to reference a java class from a Scala class, and the autocomplete feature never finds it. for example take this scala class: object Main { def main(args: Array[String]) { val btn = new JButton } } When I hit ctrl+space at the end of typ...
How can I create a jar from some Scala source code? I want to use some of that code in a Clojure project of mine. Is there a simpler way than doing batch files as in this SO question? Thanks, Alex ...
Is there a Scala API method to convert a Seq[Option[T]] -> Seq[T]? You can do this manually via: seq.filter(_.isDefined).map(_.get) Wondering if there is a method that does the above in the general API. ...
I'm learning Scala as it fits my needs well but I am finding it hard to structure code elegantly. I'm in a situation where I have a List x and want to create two Lists: one containing all the elements of SomeClass and one containing all the elements that aren't of SomeClass. val a = x collect {case y:SomeClass => y} val b = x filterNot ...
I wanted to ask if there is a list of annotations for Scala 2.8.0? I stumbled upon @inline and @specialized but it would be nice if there is a complete list which also explains what they do exactly. If such a list doesn't exist: Are there some annotations one should be familiar with? ...
There are a number of times I've run into a simple pattern when programming in Java or C++ for which a custom control structure could reduce the boilerplate within my code. It goes something like: if( Predicate ){ Action return Value } that is, a "return if"-type statement. I've tried making functions with signature lik...
I am using mockito and trying to mock a scala object. object Sample { } //test class SomeTest extends Specification with ScalaTest with Mockito { "mocking should succeed" in { val mockedSample = mock[Sample] } } Give me 2 compilation errors. error: Not found type Sample error: could not find implicit value for parameter...
Hello everyone, I'm trying to write a class for a scala project and I get this error in multiple places with keywords such as class, def, while. It happens in places like this: var continue = true while (continue) { [..] } And I'm sure the error is not there since when I isolate that code in another class it doesn't give me any e...
I've an unexpected trouble calling put on an old-school hashtable. What's going on here? Welcome to Scala version 2.8.0.final (Java HotSpot(TM) Client VM, Java 1.6.0_21). Type in expressions to have them evaluated. Type :help for more information. scala> import com.ibm.mq._ import com.ibm.mq._ scala> MQEnvironment.pro...
My problem is extracting xhtml attributes to generate absolute links, since they need to be different on testing and production environment. I would like to use a "global snippet" that binds all "src" and "href" attributes to "localhost:8080" or "www.mydomain.com" depending on a conf value. This is how the template looks like: <lift:Gl...
As the title says, when creating a multidimensional sequence in scala with tabulate, is the innermost or outermost sequence the 1. dimension? For example, in a 2-dimensional Vector v, will v(2) give the second element of the 1. or of the 2. dimension? ...
List(1,2) match { case List(1,_) => println("1 in postion 1") case _ => println("default") } compiles / works fine. So do List(1) match ... List(3,4,5) match ... but not List() match ... which results in the following error found : Int(1) required : Nothing case List(1,_) => println("1 in postion 1") Why does...
Scala 2.8 spec says in section 7.3 (highlighting is mine): Implicit parameters and methods can also define implicit conversions called views. A view from type S to type T is defined by an implicit value which has function type S=>T or (=>S)=>T or by a method convertible to a value of that type. Views are applied in two situati...
I have some Scala code that makes fairly heavy use of generics, and I have gleaned from the docs that using a manifest in the parametrization constraints can help me work around the type erasure issues (e.g. I want to instantiate a new object of the generic type). Only, I'd like to understand more about how this works. It almost feels li...
Scala is a peculiar programming language in that it targets both JVM and the CLR. But what are the benefits? Is it worth considering it as a viable alternative to the F# language? ...
I'm unhappy with the rule about variable scope in a try block not being shared with associated catch and finally blocks. Specifically it leads to code like the following: var v: VType = null try { v = new VType() } catch { case e => // handle VType constructor failure (can reference v) } finally { // can reference v. } As oppos...
Hi, I am just looking for better Scala ways of doing things, so asking newbie questions. For example: I wanted to be able to do things like the following: Given a,b,c which are "boolean": if (((a nand b) nand c) != (a nand (b nand c))) printf("NAND is not associative") Where I would cycle through possible a,b,c boolean values. I ...
I don't know elisp, but I'm trying to do something like the following: (add-hook 'scala-mode-hook (lambda () (define-key scala-mode-map (kbd "RET") (lambda () (scala-newline) (scala-indent-line))))) Goal is to call the two functions each time ...
At the moment, Im trying to understand Functional Programming in Scala and I came across a problem I cannot figure out myself. Imagine the following situation: You have two classes: Controller and Bot. A Bot is an independent Actor which is initiated by a Controller, does some expensive operation and returns the result to the Controll...
I'm interested to know the complete set of alternatives to subtype polymorphism in scala. ...