Scala 2.10.4-RC1 is now available!

We are very happy to announce the first release candidate of Scala 2.10.4! If no serious blocking issues are found this will become the final 2.10.4 version.

The release is available for download from scala-lang.org or from Maven Central.

The Scala team and contributors fixed 23 issues since 2.10.3!

In total, 39 RC1 pull requests were merged on GitHub.

Known Issues

Before reporting a bug, please have a look at these known issues.

Scala IDE for Eclipse

The Scala IDE with this release built right in is available through the following update-site:

• for Eclipse 4.2/4.3 (Juno/Kepler)

Have a look at the getting started guide for more info.

New features in the 2.10 series

Since 2.10.4 is strictly a bug-fix release, here's an overview of the most prominent new features and improvements as introduced in 2.10.0:

• Value Classes

  • A class may now extend AnyVal to make it behave like a struct type (restrictions apply).
  • http://docs.scala-lang.org/overviews/core/value-classes.html

• Implicit Classes

  • The implicit modifier now also applies to class definitions to reduce the boilerplate of implicit wrappers.
  • http://docs.scala-lang.org/sips/pending/implicit-classes.html

• String Interpolation

  • val what = "awesome"; println(s"string interpolation is ${what.toUpperCase}!")
  • http://docs.scala-lang.org/overviews/core/string-interpolation.html

• Futures and Promises

  • Asynchronously get some JSON: for (req <- WS.url(restApiUrl).get()) yield (req.json \ "users").as[List[User]] (uses play!)
  • http://docs.scala-lang.org/overviews/core/futures.html

• Dynamic and applyDynamic

  • x.foo becomes x.applyDynamic("foo") if x's type does not define a foo, but is a subtype of Dynamic
  • http://docs.scala-lang.org/sips/pending/type-dynamic.html

• Dependent method types:

  • def identity(x: AnyRef): x.type = x // the return type says we return exactly what we got

• New ByteCode emitter based on ASM

  • Can target JDK 1.5, 1.6 and 1.7
  • Emits 1.6 bytecode by default
  • Old 1.5 backend is deprecated

• A new Pattern Matcher

  • rewritten from scratch to generate more robust code (no more exponential blow-up!)
  • code generation and analyses are now independent (the latter can be turned off with -Xno-patmat-analysis)

• Scaladoc Improvements

  • Implicits (-implicits flag)
  • Diagrams (-diagrams flag, requires graphviz)
  • Groups (-groups)

• Modularized Language features

  • Get on top of the advanced Scala features used in your codebase by explicitly importing them.
  • http://docs.scala-lang.org/sips/pending/modularizing-language-features.html

• Parallel Collections are now configurable with custom thread pools

  • http://docs.scala-lang.org/overviews/parallel-collections/overview.html

• Akka Actors now part of the distribution

  • scala.actors have been deprecated and the akka implementation is now included in the distribution.
  • See the actors migration project for more information.

• Performance Improvements

  • Faster inliner
  • Range#sum is now O(1)
  • Update of ForkJoin library
  • Fixes in immutable TreeSet/TreeMap
  • Improvements to PartialFunctions

• Addition of ??? and NotImplementedError

• Addition of IsTraversableOnce + IsTraversableLike type classes for extension methods

• Deprecations and cleanup

  • Floating point and octal literal syntax deprecation
  • Removed scala.dbc

Experimental features

• Scala Reflection

  • http://docs.scala-lang.org/overviews/reflection/overview.html

• Macros

  • http://docs.scala-lang.org/overviews/macros/overview.html

The API is subject to (possibly major) changes in the 2.11.x series, but don't let that stop you from experimenting with them! A lot of developers have already come up with very cool applications for them. Some examples can be seen at http://scalamacros.org/news/2012/11/05/status-update.html.

A big thank you to all the contributors!

# | Author ---: | --- 16 | Jason Zaugg 15 | Adriaan Moors 3 | Simon Schaefer 3 | Eugene Burmako 3 | Luc Bourlier 2 | Som Snytt 2 | Paul Phillips 2 | Mirco Dotta 1 | Mark Harrah 1 | Vlad Ureche 1 | Heather Miller 1 | FrancÃßois Garillot 1 | Roberto Tyley

Commits and the issues they fixed since v2.10.3

Issue(s) | Commit | Message --- | --- | --- SI-6426 | 47562e7adb | Revert "SI-6426, importable _." SI-8062 | f0d913b51d | SI-8062 Fix inliner cycle with recursion, separate compilation SI-7912 | 006e2f2aad | SI-7912 Be defensive calling toString in MatchError#getMessage SI-8060 | bb427a3416 | SI-8060 Avoid infinite loop with higher kinded type alias SI-7995 | 5ed834e251 | SI-7995 completion imported vars and vals SI-8019 | c955cf4c2e | SI-8019 Make Publisher check PartialFunction is defined for Event SI-8029 | fdcc262070 | SI-8029 Avoid multi-run cyclic error with companions, package object SI-7439 | 8d74fa0242 | [backport] SI-7439 Avoid NPE in isMonomorphicType with stub symbols. SI-8010 | 9036f774bc | SI-8010 Fix regression in erasure double definition checks SI-7982 | 7d4109486b | SI-7982 Changed contract of askLoadedType to unload units by default SI-6913 | 70634395a4 | SI-6913 Fixing semantics of Future fallbackTo to be according to docs SI-7458 | 02308c9691 | SI-7458 Pres. compiler must not observe trees in silent mode SI-7548 | 652b3b4b9d | SI-7548 Test to demonstrate residual exploratory typing bug SI-7548 | b7509c922f | SI-7548 askTypeAt returns the same type whether the source was fully or targeted SI-8005 | 3629b645cc | SI-8005 Fixes NoPositon error for updateDynamic calls SI-8004 | 696545d53f | SI-8004 Resolve NoPosition error for applyDynamicNamed method call SI-7463, SI-8003 | b915f440eb | SI-7463,SI-8003 Correct wrong position for {select,apply}Dynamic calls SI-7280 | 053a2744c6 | [nomaster] SI-7280 Scope completion not returning members provided by imports SI-7915 | 04df2e48e4 | SI-7915 Corrected range positions created during default args expansion SI-7776 | d15ed081ef | [backport] SI-7776 post-erasure signature clashes are now macro-aware SI-6546 | 075f6f260c | SI-6546 InnerClasses attribute refers to absent class SI-7638, SI-4012 | e09a8a2b7f | SI-4012 Mixin and specialization work well SI-7519 | 50c8b39ec4 | SI-7519: Additional test case covering sbt/sbt#914 SI-7519 | ce74bb0060 | [nomaster] SI-7519 Less brutal attribute resetting in adapt fallback SI-4936, SI-6026 | e350bd2cbc | [nomaster] SI-6026 backport getResource bug fix SI-6026 | 2bfe0e797c | SI-6026 REPL checks for javap before tools.jar SI-7295 | 25bcba59ce | SI-7295 Fix windows batch file with args containing parentheses SI-7020 | 7b560213cb | Disable tests for SI-7020 SI-7783 | 2ccbfa5778 | SI-7783 Don't issue deprecation warnings for inferred TypeTrees SI-7815 | 733b3220c9 | SI-7815 Dealias before deeming method type as dependent

Complete commit list!

sha | Title ---: | --- 3fa2c97853 | Report error on code size overflow, log method name. 2aa9da578e | Partially revert f8d8f7d08d. 47562e7adb | Revert "SI-6426, importable _." f0d913b51d | SI-8062 Fix inliner cycle with recursion, separate compilation 9cdbe28c00 | Fixup #3248 missed a spot in pack.xml 006e2f2aad | SI-7912 Be defensive calling toString in MatchError#getMessage bb427a3416 | SI-8060 Avoid infinite loop with higher kinded type alias 27a38602de | Update README, include doc/licenses in distro 139ba9d875 | Add attribution for Typesafe. e555106070 | Remove docs/examples; they reside at scala/scala-dist dc6dd58d9d | Remove unused android test and corresponding license. f8d8f7d08d | Do not distribute partest and its dependencies. 5ed834e251 | SI-7995 completion imported vars and vals c955cf4c2e | SI-8019 Make Publisher check PartialFunction is defined for Event fdcc262070 | SI-8029 Avoid multi-run cyclic error with companions, package object 8d74fa0242 | [backport] SI-7439 Avoid NPE in isMonomorphicType with stub symbols. 9036f774bc | SI-8010 Fix regression in erasure double definition checks 3faa2eedd8 | [nomaster] better error messages for various macro definition errors 7d4109486b | SI-7982 Changed contract of askLoadedType to unload units by default 70634395a4 | SI-6913 Fixing semantics of Future fallbackTo to be according to docs 02308c9691 | SI-7458 Pres. compiler must not observe trees in silent mode 652b3b4b9d | SI-7548 Test to demonstrate residual exploratory typing bug b7509c922f | SI-7548 askTypeAt returns the same type whether the source was fully or targeted 0c963c9085 | [nomaster] teaches toolbox about -Yrangepos 3629b645cc | SI-8005 Fixes NoPositon error for updateDynamic calls 696545d53f | SI-8004 Resolve NoPosition error for applyDynamicNamed method call b915f440eb | SI-7463,SI-8003 Correct wrong position for {select,apply}Dynamic calls 053a2744c6 | [nomaster] SI-7280 Scope completion not returning members provided by imports eb9f0f7975 | [nomaster] Adds test cases for scope completion 3a8796da1a | [nomaster] Test infrastructure for scope completion 04df2e48e4 | SI-7915 Corrected range positions created during default args expansion ec89b59717 | Upgrade pax-url-aether to 1.6.0. 1d29c0a08b | [backport] Add buildcharacter.properties to .gitignore. 31ead67a30 | IDE needs swing/actors/continuations 852a9479d0 | Allow retrieving STARR from non-standard repo for PR validation 40af1e0c44 | Allow publishing only core (pr validation) ba0718fd1d | Render relevant properties to buildcharacter.properties d15ed081ef | [backport] SI-7776 post-erasure signature clashes are now macro-aware 6045a05b83 | Fix completion after application with implicit arguments 075f6f260c | SI-6546 InnerClasses attribute refers to absent class e09a8a2b7f | SI-4012 Mixin and specialization work well 50c8b39ec4 | SI-7519: Additional test case covering sbt/sbt#914 ce74bb0060 | [nomaster] SI-7519 Less brutal attribute resetting in adapt fallback e350bd2cbc | [nomaster] SI-6026 backport getResource bug fix 2bfe0e797c | SI-6026 REPL checks for javap before tools.jar 25bcba59ce | SI-7295 Fix windows batch file with args containing parentheses 7b560213cb | Disable tests for SI-7020 8986ee4fd5 | Disable flaky presentation compiler test. 2ccbfa5778 | SI-7783 Don't issue deprecation warnings for inferred TypeTrees ee9138e99e | Bump version to 2.10.4 for nightlies 733b3220c9 | SI-7815 Dealias before deeming method type as dependent