Scala Change History

The following list reflects changes made to older Scala distributions which have been archived offline:

• [fixed] - Fixed compiler crash in type checker. (#911)
• [fixed] - Fixed message for reported type error with implicit methods. (#900)
• [fixed] - Fixed incorrectly reported type error with trait refinements. (#892)
• [fixed] - Fixed compiler crash with view bounds. (#886)

• This version of Scala introduces some minor language changes.
• [added] - Added support multi-line expressions and definitions in the interpreter.
• [added] - The jcl library (scala.collection.jcl) provides wrappers around the Java Collections Framework.
• [changed] - Moved constants from compat.Math to their respective numeric value types (e.g. Int.MaxValue instead of compat.Math.MAX_INT).
• [changed] - The collection library (scala.collection) has been extended with new methods to make it more consistent.
• [fixed] - Fixed unreported type error for patterns. (#909)
• [fixed] - Fixed runtime crash with calls to virtual methods. (#908)
• [fixed] - Fixed object import shadowing a type. (#880)
• [fixed] - Fixed missing factory methods in case classes. (#874)
• [fixed] - Fixed compiler crash with traits. (#865)
• [fixed] - Fixed compiler crash with constant patterns. (#864)
• [fixed] - Fixed compiler crash with type mismatches in patterns. (#855)
• [fixed] - Fixed compiler crash in type checker. (#853)
• [fixed] - Fixed andThen combinator in the actors library.
• [fixed] - Fixed bug in termination detection in the actors library.

• [fixed] - Fixed runtime error with constructor parameters. (#856)
• [fixed] - Fixed compiler crash in type checker. (#852)
• [fixed] - Fixed incorrectly reported syntax error with multi-line strings. (#851)
• [fixed] - Fixed incorrect coercion of null. (#846)
• [fixed] - Fixed compiler crash. (#845)
• [fixed] - Fixed incorrect handling of finally statement in tail-call optimization. (#843)
• [fixed] - Fixed runtime crash with missing type coercion. (#842)
• [fixed] - Fixed message for reported type error with refined types. (#839)
• [fixed] - Fixed compiler crash in type checker. (#838)
• [fixed] - Fixed compiler crash with explicit outer. (#837)
• [fixed] - Fixed message for reported type error with abstract types. (#836)
• [fixed] - Restricted usage of _* in parameter lists. (#835)
• [fixed] - Fixed compiler crash in type checker. (#834)
• [fixed] - Fixed incorrectly reported type error. (#833)
• [fixed] - Fixed compiler crash with malformed types. (#831)
• [fixed] - Fixed compiler crash in type checker. (#830)
• [fixed] - Fixed runtime crash with types declared in inner classes. (#695)

• This version introduces binary incompatibilities. By recompiling all of your code, you will guarantee smooth operation. If you cannot do that, be aware of the changes below.
• [added] - Added orElse combinator to the actors library.
• [added] - Added procedure syntax as alternative to functions with type Unit as return type.
• [added] - Added sections for inherited members in generated API documentation.
• [changed] - Case classes now inherit from trait scala.Product
• [fixed] - Added identity test in generated equals operations. (#828)
• [fixed] - Fixed compiler crash in pattern matcher. (#825)
• [fixed] - Fixed runtime crash with unboxing of primitive types. (#819)
• [fixed] - Fixed compiler crash with mixin composition. (#817)
• [fixed] - Fixed compiler crash with overriden methods in mixins. (#816)
• [fixed] - Fixed very long type error messages slowing down compilation. (#815)
• [fixed] - Fixed error message for dependent constructor definitions. (#813)
• [fixed] - Fixed compiler crash in type checker with mixed-in traits. (#811)
• [fixed] - Fixed runtime crash with abstract methods. (#809)
• [fixed] - Fixed compiler crash in type checker. (#806)
• [fixed] - Fixed type error with overloading resolution of super calls. (#805)
• [fixed] - Fixed compiler crash with class inheritance and closures. (#803)
• [fixed] - Fixed missing inherited members in generated API documentation. (#801)
• [fixed] - Fixed compiler crash with abstract variable declarations. (#800)
• [fixed] - Fixed compiler crash with cyclic type parameters. (#798)
• [fixed] - Fixed compiler crash with super accessor of protected members. (#797)
• [fixed] - Fixed incorrectly reported type error with unapply methods. (#796)
• [fixed] - Fixed compiler crash in type erasure. (#795)
• [fixed] - Fixed runtime exception with Java default constructors. (#793)
• [fixed] - Fixed access to static members in nested Java classes. (#792)
• [fixed] - Fixed class cast exception. (#789)
• [fixed] - Fixed incorrect type error with mixins. (#788)
• [fixed] - Fixed compiler crash in type checker. (#785)
• [fixed] - Fixed compiler crash in type erasure. (#784)
• [fixed] - Fixed pattern matching on null values. (#781)
• [fixed] - Fixed compiler crash in type checker. (#780)
• [fixed] - Fixed compiler crash in type checker. (#779)
• [fixed] - Fixed scalap crash with JAR files in class path. (#778)
• [fixed] - Fixed two methods in class scala.io.Source. (#777)
• [fixed] - Compiler now issues a warning when annotations are not emitted in the classfile. (#775)
• [fixed] - Fixed missing substitution in pattern matching transformation. (#774)
• [fixed] - Fixed compiler crash in XML expressions. (#768)
• [fixed] - Fixed incorrectly reported type error with refined types. (#762)
• [fixed] - Fixed incorrectly reported type error with singleton types. (#758)
• [fixed] - Fixed incorrectly reported parser error with multiple packages. (#757)
• [fixed] - Fixed parser error on type expression. (#756)
• [fixed] - Fixed runtime crash with incorrectly handled abstract methods. (#754)
• [fixed] - Fixed wrong error message with mismatched function types. (#752)
• [fixed] - Fixed confusing error message with implicit views. (#729)
• [fixed] - Fixed broken case objects as patterns. (#694)
• [fixed] - Fixed incorrectly reported type error. (#599)
• [fixed] - Fixed the classfile parser to find classes in the empty package. (#580)
• [fixed] - Fixed compiler crash in type erasure. (#582)
• [fixed] - Fixed compiler crash in XML expressions with unmatched tags. (#542)
• [fixed] - Fixed uncaught type error with regular patterns. (#421)
• [fixed] - Fixed uncaught type error with intersection types. (#412)
• [fixed] - Fixed incorrectly reported type error. (#397)
• [fixed] - Fixed runtime crash with missing accessors for protected fields. (#281)
• [fixed] - Fixed incorrect type error for inner classes. (#54)
• [fixed] - Fixed several nasty bugs in the actors library.

• This version introduces binary incompatibilities. By recompiling all of your code, you will guarantee smooth operation. If you cannot do that, be aware of the changes below.
• [added] - Bytecode is generated with correct inner-class attributes (binary incompatible).
• [added] - Added section "Direct Known Subclasses" in generated API documentation.
• [changed] - The Actors library (scala.actors) has been thoroughly rewritten.
• [changed] - The collection library (scala.collection) has been extended with new methods to make it more consistent.
• [changed] - In Scala's XML API, the representation of attributes has changed from strings to full nodes, in order to account for entity references. Any reference or primitive value can now be stored in attributes. Moreover, attributes are nillable now and new node classes Group and Unparsed have been added.
• [changed] - Methods in the standard Scala library now use exceptions instead of errors.
• [fixed] - Fixed compiler crash in type checker. (#771)
• [fixed] - Fixed compiler crash in type checker. (#767)
• [fixed] - Fixed compiler crash in type checker. (#766)
• [fixed] - Fixed compiler crash in type checker. (#765)
• [fixed] - Fixed call to non existing method after mixin transformation. (#764)
• [fixed] - Fixed incorrect type error for function applications with dependent result types. (#763)
• [fixed] - Fixed missing type conformance rules in the Scala Language Specification (#761)
• [fixed] - Fixed compiler crash in type checker with arrays. (#759)
• [fixed] - finally-statement doesn't catch return. (#755)
• [fixed] - Fixed runtime crash with missing boxing operations. (#748)
• [fixed] - Fixed runtime crash with missing outer accessors. (#746)
• [fixed] - Fixed incorrect trait initialization. (#744)
• [fixed] - Fixed compiler crash in type checker. (#743)
• [fixed] - Fixed compiler crash in type checker. (#741)
• [fixed] - Fixed compiler crash in type checker. (#727)
• [fixed] - Fixed compiler crash in type checker. (#725)
• [fixed] - Fixed incorrectly reported type error. (#724)
• [fixed] - Fixed class format error with separate compilation. (#723)
• [fixed] - Fixed compiler crash in type checker. (#722)
• [fixed] - Clarified lookup rules for views in the Scala Language Specification. (#721)
• [fixed] - Fixed views which lookup too narrow. (#720)
• [fixed] - Fixed runtime crash with separate compilation. (#719)
• [fixed] - Fixed incorrect method overriding. (#718)
• [fixed] - Fixed pattern matching which ignores paths. (#717)
• [fixed] - Fixed compiler crash in type checker. (#716)
• [fixed] - Fixed compiler crash in type checker. (#715)
• [fixed] - Fixed compiler crash in type checker. (#710)
• [fixed] - Fixed runtime exception with missing main method. (#706)
• [fixed] - Fixed compiler crash in type checker. (#705)
• [fixed] - fsc doesn't return exit status. (#701)

• This version of Scala introduces some minor language changes.
• [added] - Added InnerClasses attribute in generated class files.
• [changed] - Eliminated -Xgadt option (now supported in standard).
• [changed] - Library class scala.Ordered[a] is no longer covariant in a.
• [fixed] - Fixed compiler crash in type checker. (#712)
• [fixed] - Fixed class format error for type refinements. (#711)
• [fixed] - Fixed compiler crash in type checker. (#709)
• [fixed] - Fixed compiler crash with qualified private modifier. (#708)
• [fixed] - Fixed missing debugging information for this local variables. (#707)
• [fixed] - Fixed class format error for private objects. (#704)
• [fixed] - Fixed compiler crash in type checker. (#700)
• [fixed] - Fixed implementation of abstract vals with objects. (#698)
• [fixed] - Fixed compiler crash in type checker. (#697)
• [fixed] - Fixed compiler crash in type checker with implicit parameters. (#696)
• [fixed] - Fixed compiler crash with double def's declarations. (#693)
• [fixed] - Fixed compiler crash in type checker. (#692)
• [fixed] - Fixed incorrectly reported type error with mixin composition. (#691)
• [fixed] - Fixed incorrectly reported type error with type aliases. (#690)
• [fixed] - Fixed name clash between defined and inherited members. (#687)
• [fixed] - Fixed useless import not flagged as error. (#681)
• [fixed] - Fixed runtime error with some method calls. (#680)
• [fixed] - Fixed runtime exception with incorrect boxing. (#678)
• [fixed] - Fixed runtime crash when calling methods on Java annotations (e.g. retrieved via reflection). (#676)
• [fixed] - Fixed compiler crash with private labels. (#675)
• [fixed] - Incorrect scope handling of private labels. (#674)
• [fixed] - Illegal mirror class for objects which contain case classes. (#672)
• [fixed] - Fixed compiler crash in resident mode when using attributes. (#669)
• [fixed] - Fixed compiler crash in type checker. (#668)
• [fixed] - Fixed missing line number in some error messages. (#662)
• [fixed] - Fixed infinite loop in compiler when computing type intersection. (#659)
• [fixed] - Fixed incorrectly reported type error with overriden methods. (#583)
• [fixed] - Fixed the implementation of Stream.filter and Stream.copyToArray. (#180)
• [fixed] - Fixed compiler crash when comparing bytes with chars. (#176)
• [fixed] - Fixed deadlock and stack overflow problems in package scala.actors.multi (receive method).
• [fixed] - Improved generated debug information for local variables.
• [fixed] - Added missing links for the fsc command on Unix.

• [added] - Added command fsc for the fast Scala compiler which has drastically reduced startup time compared to scalac.
• [added] - Added the actors library and API documentation.
• [added] - Added support for multi-line strings quoted with triple quote marks.
• [added] - Added support for applying Scala attributes and Java annotations to class/method parameters.
• [fixed] - Fixed compiler crash in type checker. (#664)
• [fixed] - Fixed compiler crash after reported type error. (#663)
• [fixed] - Fixed VerifyError with mixins. (#657)
• [fixed] - Fixed assert line number information. (#653)
• [fixed] - Fixed resident compiler crash with traits and name conflicts. (#652)
• [fixed] - Fixed compiler crash in tree transformer. (#651)
• [fixed] - Fixed many bugs in the Scala compiler. (#629-634,644-650)
• [fixed] - Fixed incorrectly reported syntax error with attributes. (#640)
• [fixed] - Fixed compiler crash in type checker. (#639)
• [fixed] - Fixed bug the in the scaladoc tool. (#638)
• [fixed] - Fixed compiler crash in type checker. (#637)
• [fixed] - Fixed incorrectly reported type error for implicit conversion. (#628)
• [fixed] - Fixed class cast exception. (#627)
• [fixed] - Fixed compiler crash in code lifter. (#626)
• [fixed] - Restricted symbol literals to plain identifiers. (#389)

• [added] - Added support for Java annotations.
• [changed] - Merged commands scalaint and scalascript with the command scala.
• [fixed] - Fixed compiler crash for mixed division operations. (#622)
• [fixed] - Fixed confusing error message. (#617)
• [fixed] - Fixed type inference problem with implicit methods. (#616)
• [fixed] - Fixed compiler crash in type checker. (#615)
• [fixed] - Fixed separate compilation crash. (#609)
• [fixed] - Clarified structural equality for case classes. (#551)
• [fixed] - Reduced memory usage between compiler phases.

• [added] - Added scala.throws(java.lang.Class) attribute to specify a checked exception that may be thrown by a method; can be applied more than once on the same method.
• [added] - Added a new package name _root_ from which absolute package names can be constructed.
• [added] - Added support for class literals (Predef.classOf[T]).
• [added] - Added the command scalascript to execute Scala scripts.
• [added] - Permissible values for the -target option are now: jvm-1.5, jvm-1.4 (default), msil (to be done) and cldc.
• [fixed] - Fixed many bugs in the Scala compiler. (#575,585,588,594-598,601-608,611,613)

• [fixed] - Fixed many bugs in the Scala compiler. (#568,570,571,576,577,578,579,581)
• [fixed] - Adapted batch commands for running on Windows 2000.

• [fixed] - Fixed several bugs in the Scala compiler. (#563,564,565,566)
• [fixed] - Added missing meta information for the sbaz command.
• [fixed] - Added missing API documentation for the dbc library.

• [fixed] - Fixed bug in pattern matching compilation scheme. (#560)
• [fixed] - Corrected the Unix shell scripts to be Posix-compliant. (#559)
• [fixed] - Fixed compiler crash in mixin expansion. (#404)
• [added] - Added a :replay command to the Scala interpreter.

• [fixed] - Fixed several bugs in the Scala tools.

• [fixed] - Fixed broken links in the Scala API documentation.
• [fixed] - Fixed bug in Java installer (Windows only).
• [fixed] - Fixed several bugs in the compiler.
• [added] - Integrated the sbaz tool in the Scala distribution.

• Migration to Scala 2 (see change log)
• The compiler was completely rewritten in Scala.
• [added] - Experimental support for Java generics (-Xgenerics option).
• [changed] - Simplified version numbering scheme (major/minor/patch).
• [changed] - Java installer built using IzPack instead of InstallAnywhere.

• [fixed] - Fixed NullPointerException in package scala.xml due to calculation of hashcodes of elements with null prefixes.
• [fixed] - Fixed XML pretty printer OutOfMemoryError in package scala.xml.
• [added] - scala.xml.MarkupParser does attribute normalization for character entities.
• [added] - Experimental support for database connectivity (package scala.dbc).
• [changed] - Improved batch commands (Windows only).

• [added] - Added new methods in package scala.xml (e.g. Node.text, NodeSeq.apply).
• [added] - Added Java-like Predef.exit(Int status) method.
• [fixed] - Fixed broken Ant task Scalac (Windows only).
• [fixed] - Fixed some bugs in the Scala collection library.

• [fixed] - Fixed broken batch commands (Windows only).

• [added] - Ant task scala.tools.scala4ant.ScalacTask$class is deprecated; it is replaced by the new Ant task scala.tools.scalac.ant.Scalac which supports much better classpath handling and more options.
• [added] - Added delegate support (more) on the .NET platform.
• [added] - Handling of the "encoding" attribute in the <scalac> ant task.
• [changed] - Slightly better error message for source files with wrong character encoding.
• [changed] - The Scala installer on Unix does not create an installation directory anymore and uses /usr/local/ as default.

• [added] - Experimental support for runtime types.
• [added] - Support for DTD parsing and DTD validation (provided resp. by the MarkupParser and the XML library).
• [added] - Support for Scala attributes (cf. section 5.1.7 of the Scala Language Specification).
• [added] - Added Unix man pages for the Scala tools.
• [changed] - Directory structure on Unix now conforms to the Filesystem Hierarchy Standard (FHS).
• [changed] - The match method is deprecated; it is replaced by the match keyword.
• [changed] - The XML library now deals with namespace nodes properly.
• [changed] - The Ant task ScalacTask now fails when encountering errors.
• [changed] - dtd2scala has been removed from the Scala distribution.
• [changed] - If there is no -encoding option, the compiler now uses the default encoding of the Java runtime environment (previously "ISO-8859-1").
• [fixed] - Fixed bug in pattern matching compilation scheme.

• [added] - JVM back-end: local variable tables are now generated if the -g option is given (thanks to Ross Judson)
• [added] - scala.xml.NodeSeq.Empty and the possibility to use objects of arbitrary type in XML literals.
• [added] - Parsing of Scala Mode and XML Mode is now conforming to the Scala Language Specification (see section 1.5).
• [changed] - Removal of case class scala.xml.CharData.
• [changed] - Significant rewrite of classes scala.collection.immutable.{Tree, TreeMap, TreeSet} in order to make them work with run-time types.
• [fixed] - Incorrect handling of pattern matching in some cases. (#398)
• [fixed] - Fixed wrong symbol lookup operation in case of mixin classes with overriden methods. (#396)
• [fixed] - Fixed the view which provides an order for arrays of ordered elements in object scala.Predef.
• [fixed] - Made the type argument of case class scala.:: covariant.

• [added] - scalac has a new option -printer:<printer>; e.g. -printer:swing invokes the Swing printer which displays the intermediate representation using a Swing GUI.
• [changed] - Improved handling of array types.

• [added] - Added missing hashCode() in scala.collection.immutable.Set, hash consing (simple compression of XML at load time) works again.
• [added] - scala.xml.Node has now a method toString(stripComment: Boolean) which allows to obtain an XML without any comment nodes.
• [fixed] - XML literals could not be used as keys in hashtables, despite them being immutable.
• [fixed] - Incorrect handling of overloaded methods with one argument in some cases. (#370)
• [fixed] - The .NET backend generates an incorrect .IL file when specifying a path in the -o option. (#364)

• [fixed] - Missing file in the Scala library.

• [fixed] - Fixed a nasty bug in the library file msil.jar (people using Scala on the Java platform may skip this release).

• [added] - Support for Microsoft .NET (more infos on the Scala on .NET page).
• [added] - Method closures (see §6.11) are syntactic shortcuts for anonymous functions with one parameter (e.g., given xs: List[Int], xs map (.+(1)) is equivalent to xs map (x => x+1)).
• [changed] - The syntax for types of parameterless methods has changed: they are now written "=> T" instead of "[] T" (see §3.3.1).
• [fixed] - Empty comments /**/ are now handled correctly.
• [fixed] - Case objects now have their own toString() method.

• [added] - Ant tasks for the Scala tools scala and scalap.
• [added] - XML namespace handling.
• [changed] - Several improvements in the XML library (eg. consequent use of interned strings).
• [fixed] - Minor bug fixes in the XML parser.
• [fixed] - The Web installer for Windows does not update the PATH environment variable. (#354)
• [fixed] - The compiler incorrectly handles overloaded methods in abstract classes. (#347)
• [fixed] - The compiler wrongly reports a type error in some cases. (#345)
• [fixed] - The compiler incorrectly handles import directives in some cases. (#342)
• [fixed] - The compiler backend incorrectly handles boolean expressions with primitive types. (#341)
• [fixed] - The compiler does not check for double definitions, accidental overrides. (#336,337)

• [added] - Views, which make it possible to view instances of one class as instances of some other class.
• [added] - XML literals in source code.
• [changed] - Partial implementation of valid data binding in dtd2scala. Using dtd2scala, attempts to create invalid elements result in runtime errors.
• [changed] - XML parsing and dtd2scala converted to new Java XML interface, works also with JDK 1.5 now.
• [changed] - Better runtime representation of XML literals.
• [changed] - More information items from XML Infoset (Comments, Processing Instructions, CDATA sections, Doctype Declarations).
• [changed] - Library support for XML pretty printing. Whitespace trimming.
• [changed] - Full Unicode support in identifiers and XML names.
• [changed] - Allowing '-' in XML comments if not succeeded by '-'.
• [changed] - Proper serialization of XML attribute values.
• [fixed] - scala4ant now works with Ant 1.6.x.
• [fixed] - Bug fixes in scala.xml.Utility.toString(n:Node).
• [fixed] - Unary minus handled incorrectly in constant folding. (#304)
• [fixed] - Compiler crashes on secondary constructor accessing value parameter of the class (see bug #30 of the contribution list). (#311)

• [changed] - Partial Java-style Unicode support, correct treatment of SUB and RIGHTARROW character. Letters in identifiers are still required to be ASCII or written in backquotes.
• [fixed] - Anonymous classes get non-deterministic names (meaning that in two successive compilations some classes/methods can get different names). (#316)
• [fixed] - Some fixes in the XML parser (activated using the -Xmarkup option).
• [fixed] - Some fixes in the standard Scala library (e.g. in scala.collection.mutable.AppendBuffer).

• [added] - Support for Java's static inner classes.
• [changed] - Extension of the library classes scala.Iterable, scala.Seq and scala.Array (e.g. foreach, forall, exists, foldRight, etc.).
• [changed] - Better representation of XML through scala.xml.Elem. Experimental XML expression parsing using -Xmarkup option.
• [changed] - Collection class Buffer is now an interface; use one of its subclasses ListBuffer or ArrayBuffer instead.
• [fixed] - Methods cannot have more than 256 local variables.
• [fixed] - Some fixes in the standard Scala library (e.g. in method filter of traits scala.collection.[im]mutable.Map and scala.collection.[im]mutable.Set).
• [fixed] - Implementation of floating point literals does not conform to the Scala language specification (e.g. 2.f). (#296)
• [fixed] - The Windows installer does not preserve modification date when extracting the source files of the Scala library. (#297)
• [fixed] - The Scala batch commands on Windows ignore the user-defined CLASSPATH environment variable. (#298)
• [fixed] - Compiler error when using MIN_INT and MIN_LONG integer literals. (#300)

• [fixed] - Some fixes in scalap.

• [added] - Library support for defining enumerations (scala.Enumeration).
• [added] - scalap now supports disassembling of value classes.
• [changed] - Concise syntax for defining many variables, values, methods, and classes of a given type and with a given initializer.
• [changed] - The Scala license was changed to the revised BSD license (i.e. the advertising clause was removed).
• [fixed] - The Scala batch commands on Windows do not run if the installation path contains spaces. (#288)
• [fixed] - Some fixes in the standard Scala library (e.g. in scala.collection.immutable.Queue).

• [fixed] - The MacOSX installer does not install any files.
• [fixed] - The Windows installer does not refresh the active environment. (#287)
• [fixed] - The interactive Scala interpreter (scalaint) doesn't handle user input correctly.

• [fixed] - Overloading resolution conflicts with coerce methods. (#245)

• [changed] - Base class scala.Object was renamed to scala.ScalaObject and changed to an interface.
• [changed] - Base class scala.Executable was renamed to scala.Application.
• [fixed] - Cannot access protected constructors when subclassing a Java class. (#228)
• [fixed] - Compiler error when redefining a Java method. (#229)
• [fixed] - Incorrect type of separately compiled nested modules. (#231)
• [fixed] - Compiler error when redefining a method in an anonymous class. (#238)
• [fixed] - Overloading resolution conflits with coerce methods. (#245)
• [fixed] - Sequence creation handled incorrectly in parsing. (#246)
• [fixed] - Strings handled incorrectly in constant folding. (#251)
• [fixed] - Missing bridge method for referenced abstract types. (#266)

• [changed] - Value classes are now direct subclasses of scala.AnyVal.
• [fixed] - Multi-dimensional object arrays generate wrong code. (#255)