Rakudo Star 2013.05 released


On behalf of the Rakudo and Perl 6 development teams, I'm happy to announce the May 2013 release of "Rakudo Star", a useful and usable distribution of Perl 6. The tarball and Windows .MSI for the May 2013 release are available from http://rakudo.org/downloads/star/ .

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 2013.05 of the Rakudo Perl 6 compiler, version 5.3.0 of the Parrot Virtual Machine, plus various modules, documentation, and other resources collected from the Perl 6 community.

Some of the new features added to this release include:

  • The ?-quantifier on regex captures now returns a single Match object (formerly returned an array). Use ** 0..1 to get the old behavior.
  • Failed matches return Nil instead of a false Match object.
  • Rakudo warns when pure expressions are used in sink context
  • .substr(...) now correctly accepts whatever-star closures
  • Implemented shellwords postcircumfix (%h<< $x 'foo bar' >>)
  • Defining operators spelled like the empty string is now illegal
  • Array interpolations now properly do LTM
  • Autothread "none" and "all" junctions before "any" and "one"
  • Helpful error if you write "else if"/"elif" instead of "elsif"
  • Throw exception if a Range is used as a Range endpoint
  • Corrected argument order in IO.seek
  • wrap low level VM objects in ForeignCode, allowing perl6 OO calls on them
  • for loops are eager again
  • add link and symlink to IO
  • add Capture.Bool()
  • improvements to DUMP()
  • various optimizations in the optimizer and the runtime
  • smartmatch against list now supports Whatever wildcards
  • IO::Spec, a port of Perl 5's File::Spec
  • regex special characters can be used as delimiters
  • allow slice with :exists adverb on hashes
  • added 125 extra opening/closing bracket-pairs

This release also contains a range of bug fixes, improvements to error reporting and better failure modes.

The following features have been deprecated or modified from previous releases due to changes in the Perl 6 specification, and are planned to be removed or changed as follows:

  • postcircumfix:<[ ]> and postcircumfix:<{ }> will become multi-subs rather than multi-methods. Both at_pos and at_key will remain methods.
  • Unary hyper ops currently descend into nested arrays and hashes. This will change to make them equivalent to a one-level map.
  • The Str.ucfirst builtin is deprecated; it will be replaced by Str.tc.
  • 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 result of failed matches will be Nil instead of a Match object returning boolean False.

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:

  • advanced 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 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. A 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.