Rakudo Star 2012.02 released


On behalf of the Rakudo and Perl 6 development teams, I'm happy to announce the February 2012 release of "Rakudo Star", a useful and usable distribution of Perl 6. The tarball for the February 2012 release is available from <http://github.com/rakudo/star/downloads>.

In the Perl 6 world, we make a distinction between the language ("Perl 6") and specific implementations of the language such as "Rakudo Perl". This Star release includes release #49 of the Rakudo Perl 6 compiler [1], version 4.1 of the Parrot Virtual Machine [2], and various modules, documentation, and other resources collected from the Perl 6 community.

Here are some of the major improvements in this release over the previous distribution release.

  • The FatRat type is implemented, and Rat arithmetic now properly defaults to Num if the denominator is too big
  • Object hashes are implemented, and can be declared with the syntax my %h{Any} (for a hash with keys of type Any)
  • The <Some::Grammar::rulename> syntax is now implemented in regexes; <foo> can also be used to call predeclared lexical rules
  • The Int($x) coercion syntax is implemented
  • &rename and &copy are now implemented
  • Improvements to the reduction meta-operator (order of magnitude faster, some parsing issues fixed)
  • The <prior> regex built-in is now available, and matches whatever the last successful match matched
  • A $match.make(...) method is available to set the AST for a match object not stored in the $/ variable
  • Improved backtraces

This release also contains a range of bug fixes, improvements to error reporting and better failure modes. Many more exceptions are thrown as typed exceptions.

Due to continued evolution of and convergence with the Perl 6 spec, there are some changes to existing functionality that may affect your code:

  • You may no longer use the $.x form in submethods and attribute initializers, as per spec; use the non-virtual $!x instead.
  • The LHS of the xx operator is now thunked
  • .conjugate is now called .conj
  • Enumeration values .gist to just the key, not the full name
  • An empty Buf is now False in boolean context

Currently, we have maintained backwards compatibility with some changed pieces of syntax, but will drop them in an upcoming release:

  • "<...>" in proto regex bodies; now this should be written "*"
  • The use of "**" with a separator in regexes; this is now done by using "%" or "%%" on another quantifier

There are some key features of Perl 6 that Rakudo Star does not yet handle appropriately, although they will appear in upcoming releases. Some of the not-quite-there features include:

  • pack and unpack
  • macros
  • threads and concurrency
  • Unicode strings at levels other than codepoints
  • pre and post constraints, and some other phasers
  • interactive readline that understands Unicode
  • non-blocking I/O
  • much of Synopsis 9

There is a new online resource at http://perl6.org/compilers/features that lists the known implemented and missing features of Rakudo Star 2012.02 and other Perl 6 implementations.

In many places we've tried to make Rakudo smart enough to inform the programmer that a given feature isn't implemented, but there are many that we've missed. Bug reports about missing and broken features are welcomed at <[email protected]>.

See http://perl6.org/ for links to much more information about Perl 6, including documentation, example code, tutorials, reference materials, specification documents, and other supporting resources. An updated draft of a Perl 6 book is available as <docs/UsingPerl6-draft.pdf> in the release tarball.

The development team thanks all of the contributors and sponsors for making Rakudo Star possible. If you would like to contribute, see <http://rakudo.org/how-to-help>, ask on the [email protected] mailing list, or join us on IRC #perl6 on freenode.

[1] http://github.com/rakudo/rakudo [2] http://parrot.org/