scala-2.10

How can I extract the field values from a case class in scala using the new reflection model in scala 2.10? For example, using the below doesn't pull out the field methods def getMethods[T:TypeTag](t:T) = typeOf[T].members.collect { case m:MethodSymbol => m } I plan to pump them into for {field <- fields} { currentMirror.reflect(caseClass).reflectField(field).get } Travis Brown MethodSymbol has an isCaseAccessor method that allows you to do precisely this: def getMethods[T: TypeTag] = typeOf[T].members.collect { case m: MethodSymbol if m.isCaseAccessor => m }.toList Now you can write the

So I've got this macro: import language.experimental.macros import scala.reflect.macros.Context class Foo class Bar extends Foo { def launchMissiles = "launching" } object FooExample { def foo: Foo = macro foo_impl def foo_impl(c: Context): c.Expr[Foo] = c.Expr[Foo](c.universe.reify(new Bar).tree) } I've said three times that I want foo to return a Foo , and yet I can do the following (in 2.10.0-RC3): scala> FooExample.foo res0: Bar = Bar@4118f8dd scala> res0.launchMissiles res1: String = launching The same thing happens if I remove the type parameters on either c.Expr . If I really want to

I have some code like this: class ReflectiveJsonFormat[T:TypeTag] extends JsonFormat[T] { def write(x: T) : JsValue = { val t = typeOf[T] val getters = t.declarations.filter { s => s.isMethod && s.asMethod.isGetter } val mirror = runtimeMirror(this.getClass.getClassLoader) val instanceMiror = mirror.reflect(x) } } That last line fails with: No ClassTag available for T I thought TypeTag was more info than a ClassTag ? Can I get the ClassTag from the TypeTag ? If not, is there some syntax for saying that T has two context bounds -- both TypeTag and ClassTag ? Or, how would you otherwise fix this

I'm relatively new to Scala and am trying to define a generic object method. However, when I refer to the parameterized type within the method I am getting "No ClassTag available for T". Here is a contrived example that illustrates the problem. scala> def foo[T](count: Int, value: T): Array[T] = Array.fill[T](count)(value) <console>:7: error: No ClassTag available for T def foo[T](count: Int, value: T): Array[T] = Array.fill[T](count)(value) ^ Thanks in advance for help in understanding what is wrong here and how to make this contrived example work. Régis Jean-Gilles To instantiate an array in

I came across the scala.concurrent.blocking method, and according to the Scala documentation this is... Used to designate a piece of code which potentially blocks, allowing the current BlockContext to adjust the runtime's behavior. Properly marking blocking code may improve performance or avoid deadlocks. I have some doubts: what is the factor with which new threads will be spawned? Is this applicable only for scala.concurrent.ExecutionContext.Implicits.global execution context or for user-created execution contexts as well? What happens if I wrap any executable with blocking { ... } ? Any

I'm looking at alternatives to -print or javap as a way of figuring out what the compiler is doing in Scala. With the new reflection/macros library, reify seems a good candidate for that, as shown in retronym's macrocosm 's desugar . It even shows how one used to do that, pre-M4. So the question is, what's the shortest/easiest thing I can type on Scala's REPL to get the AST for an expression, post-Scala 2.10.0-M4? kiritsuku A lot of things previously defined in package scala.reflect.mirror have moved to scala.reflect.runtime.universe : scala> import scala.reflect.runtime.{universe => u} import