Scala 2.10.0 Milestone 2

A new milestone release for Scala is now available. This release is cut directly from current development and is not intended for production environments, but is a great chance to try out the up and coming features for Scala 2.10.0.

This milestone includes the following fixes and improvements:

• Support for implementing a parallel collection using a concurrent collection. In particular, one should be able to implement a combiner using a concurrent (thread-safe) collection.
• Ctries added to the standard library. Implement parallel ctries using the above mechanism.
• New futures and promises library added to scala.concurrent, joint work with the Akka team.
• Numerous improvements to reification.
• Virtual pattern matcher improvements -- please try compiling your project with -Yvirtpatmat, it will be on by default starting with 2.10.0-M3!
• A significantly faster optimizer.
• Improvements to RedBlack tree.
• Fixes to specialization (AnyRef, interaction of final and @inline -- thank you, Erik Osheim!).

Specifically, though non-exhaustively, the following tickets were closed (we're working on automation to make this more reliable):

• SI-4336 polymorphic expression isn't adapted to the expected type
• SI-4835 scala.collection.immutable.StreamIterator[+A] has O(n) memory consumption
• SI-5066 Predef.readLine(String, Any*) should call Console.readLine(text, args: _*) (Thank you, Szabolcs Berecz!)
• SI-5215 Scalac crashes when I use @elidable for trait (Thank you, Szabolcs Berecz!)
• SI-5224 Cannot reify @serializable class C
• SI-5225 Bad reification of @transient @volatile var x = 2
• SI-5229 Cannot reify objects
• SI-5256 Classloading problems in REPL with Scala reflection
• SI-5269 Cannot reify traits
• SI-5270 Cannot reify self-types
• SI-5271 Cannot reify case classes
• SI-5272 Cannot reify simple pattern match
• SI-5273 Cannot reify unapply-based pattern match
• SI-5274 Cannot reify recursive functions
• SI-5275 Cannot reify constructors with val-parameters
• SI-5276 Cannot reify lazy vals
• SI-5277 Cannot reify implicits
• SI-5279 Cannot reify implicitly imported stuff from java.lang
• SI-5287 Use case methods hide information about the actual method
• SI-5293 Performance: Copying mutable.HashSet (FlatHashTable) 100x slower than java.util.HashSet.
• SI-5334 Cannot reify code that returns an object of a locally defined type
• SI-5335 Cannot reify anonymous classes
• SI-5374 Deserialization of ListBuffer results in a non-mutable structure prone to throwing NoSuchElementException
• SI-5375 Deadlock when parallel collection function throws an exception
• SI-5405 Documentation error in scala.math.BigInt
• SI-5419 Cannot reify 5: @Int
• SI-5423 Mirror doesn't load annotations
• SI-5429 object may override a def causing ClassCastException in unrelated code
• SI-5444 Crash in LambdaLift
• SI-5452 Stack overflow in doTypedApply when manifests meet overloads
• SI-5497 undefined value leads to "no-symbol does not have an owner"
• SI-5500 Strange type error with some AnyRef specializations (but not others)
• SI-5506 cps errors with lists 

Many thanks to everyone who contributed patches since the previous milestone:

Daniel C. Sobral, Erik Osheim, Erik Rozendaal, Geoff Reedy, Jason Zaugg, Kota Mizushima, Leif Wickland, Lucien Pereira, Ruediger Klaehn, Szabolcs Berecz