Hague Perl 6 Grant for Jonathan Worthington completed and accepted

In late November 2007 Jonathan Worthington submitted a "Hague Perl 6 Grant proposal":http://www.perlfoundation.org/ian_hague_perl_6_development_grants entitled "'Rakudo Dispatch and Role Enhancements'":http://news.perlfoundation.org/2008/11/hague_grant_request_rakudo_dis.html. I am pleased to announce that Jonathan submitted his final Hague grant report yesterday (included below the fold), and it was approved and accepted by chromatic, the grant manager for the grant. This successfully completes this Hague Grant for Perl 6 development. We thank Jonathan for his great work on this grant and his efforts in advancing the goal of a completed Perl 6 implementation.

Introduction In the months during which I have worked on my Hague Grant, Rakudo Perl 6 has taken some huge steps forward - not just as a result of my work and this grant, but as the result of the efforts of a growing Rakudo Perl 6 user and developer community. When I submitted my grant proposal I noted that we passed over 4,000 tests. Today we pass over 10,000, are more stable and have a much wider feature set. Thus my work on the deliverables of this grant have been part of a wider scene of extensive Rakudo progress.

Deliverables Status All deliverables have been achieved. In places, my work has gone beyond what the grant required. Reactions to my work have been positive, both from users and other developers.

D1. We now register types in the symbol table at compile time and the hack that saw us through the early days is removed. Furthermore, I have used this to build some other features, including compile time detection of type re-declaration.

D2. Junction auto-threading is now fully implemented for both single and multiple dispatch. The Perl 6 multi-dispatcher knows how to generate and cache junction dispatchers for future performance too. As various built-ins have moved over to the Perl 6 prelude, they too have gained the auto-threading automatically. I also reviewed and added a range of tests[1] to exercise the auto-threading, including ensuring that interaction with multis and auto-threading as well as nested junctions work as expected.

D3. I implemented submethods and reviewed and enabled the tests for them.

D4. The handles trait verb has been extensively refactored and now handles many more cases. I reviewed, enabled and added to the spectest suite tests[2] relating to this, to improve test coverage.

D5. This has by far been the most significant and complicated deliverable of the grant, and what has been achieved in this area exceeds what was originally required. First and foremost, we now have an implementation of parametric roles. They can be declared, composed and mixed in, the selection falling naturally out of the usual multi-dispatch semantics as is specified.

In addition to this, I have converted the Positional, Associative and Callable roles to be parametric. This, along with a little bit of extra work in the compiler, has now given us typed arrays, hashes and routines

• features from S09 and S06. This has served as a great concrete test of parametric roles. It has also won us sigil-based multi-dispatch and multi-dispatch based upon typed data structures too.

Test coverage for parametric roles was weak (understandable, because nobody had implemented them before), and I have expanded this greatly during my work[3],[4],[5]. Some tricky areas - including parametric roles recursively parametrized and parametric role subtyping - a feature not in the specification at the time I started the grant - are now well exercised.

I rounded this work off by updating S14[6] (the specification for roles, which has been broken out from S12 since I started this grant). It is now more detailed and complete.

Dissemination</