Tonight Liz and I specified a very strange but powerful alarm() construct in S17 draft, and cleared up S17 a bit in general.
Among the runtimes, probably only the Haskell one can implement them in full at this moment, although the others can simulate the behaviour using lightweight multiplexing.
I learned that Parrot's threading code (and design) are currently missing... So after Chip is done with the lexical pads, I'd like to work with him and Leo a bit, to make sure that we are on the same page at grokking the STM+Continuation model. Come to think about it, maybe Dan will suddenly decide to publish Cola's subversion repository and come up with some related stuff as well...
Stevan started working on the MetaModel Bootstrapping sequence, a shared call graph on runtime-provided kernel objects that will establish the Perl 6 object model. The good thing is that it is agnostic to runtimes -- I need only to implement the small amount of underlying intrinsics in Haskell, then we can get a object model for free. This approach is taken from PyPy, with some influence from Ruby/YARV as well. Hurray for symbiotic evolution! :-)
I checked in some fix to Parrot's overview.pod, removing a paragraph that has bothered me for a long time. Originally, it claimed that Parrot can make use of the vast amount of research literature on compiling to hardware CPUs, compared to the fewer papers on compiling to stack machines. The reality however is that most hardware papers doesn't apply to the infinite-register Parrot, and there just are not many papers on Itaniums (which resembles Parrot the most), compared to the huge amount of JVM and CLR papers.
I changed it to say that in non-JIT settings, register machines takes fewer operations to perform typical high-level language tasks, and the new scheme of "lexicals are just registers" extends this benefit to intermediate values held in variables as well. Now I feel much happier. For more detail, see this paper referred from Jonathan.
Liz notices that in our Perl 5 embedding examples,
we always start with use perl5:DBI;, which is a pretty good indication of the number one module to port over from Perl 5. It turns out that the guts of DBI::PurePerl and stub DBDs are just a few hundred lines, and dduncan volunteered to take a look to port it over to Perl 6, possibly even with a port of DBD::mysqlPP using Pugs's existing sockets support. Woot!
That's it for today, I think. See you tomorrow!
