The Perl 6 Summary for the week ending 20050814
As you will note from the date in the title, it's been a short week.
We're switching back to a midnight Sunday/Monday rollover in order to
make life easier for the perl.com types. So, if I can avoid being
distracted too much by the second Ashes test we'll try and get the
summary finished on before Monday is out, which should please chromatic.
This week in perl6-compiler
Another low volume week in perl6-compiler; probably because, with the
high speed of pugs development, most of the discussion happens on IRC.
Container model - pictures and questions
Autrijus fielded some questions about and updated the pictures of the
container model.
<http://xrl.us/g5kk>
Why PXPerl?
Robert (No Surname) asked what were the benefits of PXPerl over the
ActiveState distribution. In short, PXPerl comes with Parrot and Pugs,
which ActiveState doesn't. If you set your path appropriately, you can
continue to use the ActiveState Perl and just rely on PXPerl for Parrot
and Pugs.
<http://xrl.us/g5km>
Hoisting lexical declarations
Larry answered some of Autrijus's questions about Perl 6's lexical
scoping rules. Apparently what Pugs currently does is close enough to
sane to be going on with.
<http://xrl.us/g5kn>
Warnock in Pugsland
Autrijus noted that, in Pugsland, a Warnocked patch usually means that
the person who posted the patch simply got given a committer bit and
didn't mention the fact on the list.
<http://xrl.us/g5ko>
MetaModel Notes
Nathan Gray posted some notes and ASCII art about the Metamodel.
Autrijus added pointers to further pictures.
<http://xrl.us/g5kp>
<http://xrl.us/g5kq>
<http://xrl.us/g5kr>
Meanwhile, in perl6-internals
Updated intro.pod
Jonathan Worthington posted a rewrite of Parrot's intro.pod document,
now with a discussion of PIR. Huzzah!
<http://xrl.us/g5ks>
Test::Builder and friends on Parrot
Following prompting from Geoff Young and Jeff Horwitz, chromatic has
implemented Test::Builder and Test::Builder::Tester in pure parrot. For
his next trick, he intends to port Test::More and Parrot::Test.
Tests are good, m'kay?
<http://xrl.us/g5kt>
How to add a new opcode?
Gerd Pokorra asked how to add an opcode to Parrot. Klaas-Jan Stol and
Leo gave the answers.
<http://xrl.us/g5ku>
Cleaning up the call opcodes
Leo reposted about cleaning up the various function calling opcodes to
take account of the fact that the calling conventions have changed. He
asked for opinions and actually got a couple, which is handy since he
got Warnocked last time.
<http://xrl.us/g5kv>
"parrot -I"
Amir Karger wondered if there was some way of telling Parrot to add
directories to its load path. Leo seemed not to think it was that good
an idea, and proposed using a relative path in a ".include" directive.
<http://xrl.us/g5kw>
Dominance Frontiers
Curtis Rawls continued his work on dominance frontiers to improve
Parrot's optimizer.
<http://xrl.us/g5kx>
PGE globber, empty strings
Will Coleda reported that trying to match empty strings with PGE's
"glob" implementation. It turned out to be a problem with Data::Escape.
Leo fixed it.
<http://xrl.us/g5ky>
Deprecated opcodes
Leo posted a list of opcodes that are due for the chop (or alteration)
soon. If you're doing anything with Parrot, it's probably a good idea to
take a look at this. One of those who did was chromatic, who asked if
Leo could give some examples of translating code so as not to use the
old forms.
<http://xrl.us/g5kz>
Meanwhile, in perl6-language
Hmm... 8 balls to go with one wicket needed. I think I'll pause for a
while...
Damn. Australia have saved the game.
Translating (or at least parsing) Java interface definitions
Tim Bunce wondered if anyone had done any work on parsing Java interface
declarations and (ideally) translating them to roughly equivalent Perl
6. Apparently Gaal Yahas has done something along these lines (with
Parse::RecDescent for Perl 5) but doesn't own the code. He outlined the
approach he took.
<http://xrl.us/g5k2>
Perl 6 Meta Object Protocols and "$object.meta.isa(?)"
Stevan Little is busy documenting the Perl 6 Meta Model that he's
implemented in Perl 5 and that Autrijus is busy porting to Haskell. He
posted an overview to the list and asked for comment. There then
followed lots of discussion. I think I understood some of it.
<http://xrl.us/g5k3>
"$object.meta.isa(?)" redux
Stevan split the discussion of "$object.meta.isa(?)" off from the
earlier metamodel thread into a thread of its own and asked for comments
once more. Larry commented that "the Apocalypses are primarily intended
to be entertaining rather than factual". Also in this thread, Luke let
slip that there's now a 'Set' role in Perl 6, which has the enormous
advantage of letting us specify argument types in a sensible way without
having to overload the Junctions.
<http://xrl.us/g5k4>
"$obj.meta.add_method('foo' =" ???)>
Stevan continued discussing the metamodel with a thread about the
"add_method" method. Autrijus was the only person with comments.
<http://xrl.us/g5k5>
Proposed new traits
Autrijus said that he'd started to write the inferencer and had
immediately run into the problem that every type can potentially contain
"undef". He proposed adding an "is defined" trait, which would cause
variable to immediately throw an exception if anyone attempted to assign
it an undefined value. He also proposed a "typed" trait, but I was a
little less clear on why this would be a good idea. I have to confess I
didn't understand what Larry's reply was driving at, but that's okay
because Autrijus did seem to understand it.
<http://xrl.us/g5k6>
"my $pi is constant = 3"
Autrijus wondered if an example of the "is constant" trait shown in
Synopsis 6 was a special form or a typo. At least, I think that's what
he was asking; I may be wearing my stupid head today though. Larry
thought it was neither. I think. It seems there's more to constancy than
meets the eye. (Just ask any married couple).
<http://xrl.us/g5k7>
Typed type variables ("my Foo ::x")
Stuart Cook asked about the meaning of type annotations on
type-variables. Autrijus answered and Thomas Sandlaß agreed with him.
<http://xrl.us/g5k8>
"BEGIN {...}" and IO
Nicholas Clark commented on an earlier discussion of using IO in "BEGIN"
blocks, pointing out that this was just a specific case of the more
general problem of attempting to serialize things to bytecode which were
simply unserializable. I reckon the trick of it will be to do such
things in "INIT" or possibly "CHECK" blocks (I can never remember which
way round those two go).
<http://xrl.us/g5k9>
Generic Classes
Autrijus asked about generic classes, but nobody answered before the end
of the summary week. Expect Matt to address this one in the next
summary.
<http://xrl.us/g5ma>
Acknowledgements, adverts, apologies and alliteration
I'm sorry to have to say this, but I don't think I have to apologise for
anything this week. WorldCon was fun.
Help Chip
<http://geeksunite.org/>, tell all your friends, this cannot stand.
The usual Coda
If you find these summaries useful or enjoyable, please consider
contributing to the Perl Foundation to help support the development of
Perl.
<http://donate.perl-foundation.org/> -- The Perl Foundation
<http://dev.perl.org/perl6/> -- Perl 6 Development site
Check out my website, it's lovely.
<http://www.bofh.org.uk/>
Vaguely pretty photos by me can be found at:
<http://xrl.us/g5mc>
