The Kiama team are pleased to bring you the next release of the library.

This release includes some breaking changes that improve the reliability and safety of Kiama-based applications. All users should take careful note of these changes.

In addition, there are quite a few new features and bug fixes, most notably a new chain decorator for threading attributes through a tree, support for minimal parenthesisation in pretty printing, and callback support for rewriting. A new version of the Oberon-0 example shows how Kiama can be used in an extensible, modular way.

Breaking changes

• General
  • Kiama’s group ID is now com.googlecode.kiama instead of com.googlecode to fit with Maven Central policies. In sbt you can use it with the following dependency.

  "com.googlecode.kiama" %% "kiama" % "1.2.0"

• Attribution
  • Basic attributes are now normal functions, not partial functions, so pattern match completion checking works on their definitions. This change may require some fixes to declared types and may reveal incompleteness that was hidden before.
  • Node properties in Attributable such as parent are not automatically set any more. If you want to use them, first call the Attribution.initTree method, passing the root of your tree. This change removes a set of bad behaviours caused by setting these properties at node construction time.
  • Attributable does not extend scala.util.parsing.input.Positional any more, since it didn’t use it.
• Rewriting
  • Remove Rewriter implicit conversions from Term and Option[Term] to Strategy because they were too dangerous. Use the new explicit operations build and option instead.
• Output
  • Pretty printing library moved to new org.kiama.output package from org.kiama.util.

New features

• Attribution
  • Add chain decorator for threading attributes through a tree.
  • Non-circular attributes now have a reset method which clears their cache.
  • Add clone and deepclone support to Attributable. Cloning is important if you intend to calculate some attributes on a structure that would otherwise contain duplicate occurrences of nodes.
  • The current node is now reported in the exception thrown when a cycle is detected during calculation of a non-circular attribute.
  • Support for node properties of tuple, Some and GenTraversable children.
• Output
  • Add ParenPrettyPrinter trait for pretty-printing with minimal parenthesisation.
  • Updates to PrettyPrinter
    • Make conversions from String and Char to pretty-printer Doc type implicit.
    • Split list combinator into list (for lists of values) and plist (for list of pretty printables).
    • Add hsep, vsep and fillsep variants that allow a separator to be given.
    • product combinator now does something sensible for vectors, maps and tuples.
    • Add lterm combinator for lists with terminated elements.
• Rewriting
  • Add log and logfail combinators to Rewriter to improve debugging of rewriting phases.
  • Add CallbackRewriter extension of Rewriter that adds callbacks to various rewriting operations. The callback provides both the node that is being rewritten and the node to which it is being rewritten.
  • Add PositionalRewriter extension of CallbackRewriter that automatically copies positions when rewriting scala.util.parsing.input.Positional nodes .
• Utilities
  • Add ParserUtilities trait containing helper support for using Scala combinator parsers, most notably implicit conversions so that case class constructors can take “tilde” tuples, thereby eliminating a lot of the pattern matching that you normally need to do in parser actions.
  • Add WhitespaceParser trait which allows white space to be defined using a parser instead of a regular expression when using RegexParsers and PackratParsers. This capability is useful when white space contains comments that are nestable.
  • Add Patterns module to contain useful extractors (just HasParent for Attributable now).
• Examples
  • Add Oberon-0 example including attribution, rewriting and pretty-printing, plus assembly of processors from smaller components in a modular fashion.
  • Add small JSON example.
  • 101companies example now includes some attribution.
• Testing
  • Add tests to improve code coverage.
  • Allow tests to capture output during command-line argument processing.
• General
  • Move to Scala 2.9.1, ScalaTest 1.7.1, JLine 1.0 and sbt 0.11.
  • Add console import commands to build.sbt so that interactive testing is easier.

Fixes

• Rewriting
  • Use while loops instead of for comprehensions to iterate over children in generic traversal combinators to gain significant speed-up.
  • The Product node duplication operation now caches constructors to reduce reflection overhead.
• Utilities
  • Messaging.report now defaults its Emitter argument to standard output.
• Examples
  • Ignore lines that only contain white space in REPLs.
• Testing
  • Change some test names so that bits don’t disappear when run by Eclipse JUnit runner.
  • Make a better split between basic code and test code so that normal compile doesn’t need the test libraries.
• General
  • Publish in Sonatype OSS repository (and hence Maven Central) instead of on www.scala-tools.org.
  • API documentation on http://kiama.googlecode.com now includes links to source.
  • Example and test API documentation is now published as well.
  • Add tree-oriented navigation links to the wiki documentation.
  • Many other small bug fixes, improvements and documentation clarifications.