Rakudo Star 2012.08 released


On behalf of the Rakudo and Perl 6 development teams, I'm happy to announce the August 2012 release of "Rakudo Star", a useful and usable distribution of Perl 6. The tarball for the August 2012 release is available from http://github.com/rakudo/star/downloads. A Windows .MSI version of Rakudo Star is also available from the download site.

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 2012.08 of the Rakudo Perl 6 compiler, version 4.6 of the Parrot Virtual Machine, and various modules, documentation, and other resources collected from the Perl 6 community.

Some of the new features added to this release include:

  • Rakudo Star now includes a Perl 6 debugger! The debugger allows single-stepping, setting breakpoints, variable inspection/modification, regex debugging, and more! Enter "perl6-debug script.pl" to run a script in debugging mode. Enter "help" from a debug prompt to see the available commands.

  • Memory usage of the build stage has been reduced by 35% - 40%. This makes it possible to build and compile Rakudo Star on machines with less memory (although 1.2GB may still be needed for some 64-bit environments).

  • Variables prefixed by | or \ in signatures are now sigilless, per updates to the Perl 6 specification.

  • Circularities in module loading are now detected.

  • An improved inliner, allowing a wider range of routines to be inlined.

  • Str.bytes and lcfirst have been removed. The tclc builtin has been added.

  • 'abs' is now a normal subroutine instead of a prefix operator.

  • IO::File and IO::Dir have been removed.

  • The integer argument to IO::Socket.recv is now interpreted as a number of characters/codepoints.

This release also contains a range of bug fixes, improvements to error reporting and better failure modes. More exceptions are thrown as typed exceptions, and more meta-model errors have been fixed to properly report line numbers.

We also identify changes to the implementation or specification that can cause breakages in existing Perl 6 code. The following features have been deprecated or modified due to changes in the Perl 6 specification, and are being removed or changed as follows:

  • Parameters preceded by a | or \ can no longer have a sigil.

  • IO::Path.dir (which returns the directory part of the path) has been renamed to IO::Path.directory. IO::Path.dir will be removed or re-purposed.

  • The Str.ucfirst builtin is deprecated; it will be replaced by Str.tc.

  • The (experimental) LAZY statement prefix will soon be removed.

  • Leading whitespace in rules and under :sigspace will no longer be converted to <.ws> . For existing regexes that expect this conversion, add a in front of leading whitespace to make it meta again.

  • The ?-quantifier on captures in regexes currently binds the capture slot to a List containing either zero or one Match objects; i.e., it is equivalent to "* 0..1". In the future, the ?-quantifier will bind the slot directly to a captured Match or to Nil. Existing code can manage the transition by changing existing ?-quantifiers to use "* 0..1", which will continue to return a List of matches.

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:

  • macros
  • threads and concurrency
  • Unicode strings at levels other than codepoints
  • interactive readline that understands Unicode
  • non-blocking I/O
  • much of Synopsis 9

There is an online resource at http://perl6.org/compilers/features that lists the known implemented and missing features of Rakudo Star 2012.08 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 rakudobug@perl.org.

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. A draft of a Perl 6 book is available as 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 perl6-compiler@perl.org mailing list, or join us on IRC #perl6 on freenode.