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I'm sorry to have to inform you that I've returned from my holiday (no, base jumping and paragliding were not involved) and that this week's summary will not be written by the estimable Leon Brocard. Sorry about that. Leon is currently taking a rest cure.
So, with the customary mention of Mister Brocard out of the way good and early this week, it's time to take a look at what's been discussed on the internals list:
Newcomer Karthik Kumar is interested in writing a tool to convert java
.class
files to parrot .pbc
files and asked for information on
what had been done in this area. Leon Brocard says it's very easy to
get the basics working because of the low number of JVM bytecodes. But
getting the fundamentals (classes, objects) right is hard. Ramesh
Ananthakrishnan commented that it might be a little early for anything
more than proofs of concept at the moment as Parrot is a rapidly
moving target. Ramesh also came up with the idea of compiling `real
machine' assembly language to `virtual machine' parrot assembler.
Karthik commented that the real issue seems to be one of what level of support Parrot will offer for objects, and until that is known the class->parrot problem is almost pointless to solve.
groups.google.com -- Ramesh clarifies his `Linux in Parrot' idea.
Erik Lechak is still not loving POD but, despite his distaste he posted version 0.4 of his getting started guide in POD format. Thanks a lot Erik. Marty Pauley suggested that Erik take a look at the Simple Document Format which may meet his needs better than POD
Rhys Weatherly, author of Portable.NET, part of the DotGNU project made a welcome appearance on the list. Apparently the DotGNU people are looking into compiling C# down to parrot bytecode and hoped that there might be parrot people who were interested in trying to complete their compiler and system library.
Rhys wanted to know how to make a user-defined class in Parrot; what
the convention is for which registers must be saved across a call;
the size of int
and whether there was a way to store and access
auxiliary data in a Parrot bytecode file.
Answers were provided. Sadly, the answer to Rhys's question about user-defined classes was "You don't, yet." Other answers were more immediately useful.
The DotGNU weekly IRC meeting discussed Parrot this week, Leon and Dan managed to cover both sessions between them, and there's a log available.
dotgnu.info -- Condensed summary of the meeting
ajmitch.dhis.org -- unedited logs available here
Leopold Toetsch rather confused me when he replied to a two week old message (I thought I'd completely screwed up setting the `limit by date' values in my summary buffer) about the conceptual split between variables and values. Leo wanted some clarification which Dan provided.
groups.google.com[63.120.19.221] -- Dan's old message
groups.google.com -- Leo's questions
Leon Brocard attempted to kick start discussion of Jonathan Sillito's
patch to pass more information when creating new PMCs. Leopold Toetsch
and Josef Höök both said they thought that something along
those lines was a good idea, but the discussion seemed to die
there. Later in the week, Dan introduced the new init_pmc
function
to PDD02, which works along the lines suggested.
groups.google.com[63.120.19.221]
Clinton A. Pierce wondered about how to do the equivalent of exists
$hash{$key}
in Parrot when one doesn't necessarily know the types of
the things in the hash. Leo Toetsch pointed to exists_keyed
and
type_keyed
. Jason Gloudon pointed out that the docs for
type_keyed
referred only to PMCs, with no mention of 'primitive'
types. He wondered if PerlHash shouldn't just dictate that its
contents were all PMCs.
The language group is trying to catch up with internals in number of posts. They managed 89 posts this week compared to internals' 96. If you discount attachments, language probably won on volume (and it certainly wins hands down on the `difficulty of summarization' metric).
The discussion of how to declare classwide attributes rumbled on from last week; I'll just pick out a few nuggets.
HASH
, <ARRAY> etc will likely become <Hash>, <Array> etc,
and there's a good chance that UNIVERSAL
will become Object
groups.google.com -- Thread starts here
www.aw.com -- the Metaclasses book
The `Operator Precedence' thread kept on rolling from last week. The
current game appears to be `working out how to free &
and |
to
become superposition constructors', which means hanging the bitwise
operators somewhere else. Various ideas have been proposed, but people
really didn't like |||
and &&&
. The current front runners appear
to be:
$a b& $b
$a .& $b
It looks like this whole area is still somewhat fluid though.
untaintby
propertyMiko O'Sullivan proposed an untaintby
property which `restricts
which modules may untaint the data or data derived from that data.'
The feedback wasn't that positive, but Larry came up with the idea of
callbacks on properties which look rather cool. (`too cool!' according
to Miko).
Michael Schwern opened a can of worms when he wondered if 1/0
would
throw an error or just return a value representing an indeterminate
result. Leon wondered if it'd be possible to, for instance have a
module which did all its arithmetic in, say, integers module prime
P. Dan thought yes, with lots of overloading. Adam Lopresto thought
1/0
would be a good place for the new fail
semantics. We ended
up in a debate about the mathematical values of $n/0
(apparently
x/0 is indeterminate when x is zero and undefined otherwise).
This thread also saw discussion of: the nature of Object Orientation
and the benefits of instance based inheritance; the
semantics of NaN. (Did you know that NaN != NaN
; the use of
exceptions; proofs that 1/0 is, necessarily, undefined; Lukasiewiczian
logic (SQL type NULLs); Miko's `inner Larry Wall'; and the hypothetical
Math::Perverse
module, which sounds like a candidate for the Acme
namespace to me.
Larry seems to think that a combination of pragmas and overloaded classes should be enough to do the job.
groups.google.com -- complete with citation of www.userfriendly.org
Miko O'Sullivan has been doing some serious thinking. After wowing us
with his untaintby
proposal, he came up with some proposals for
exceptions which would allow for all sorts of cunning tricks. Dan
pointed out that at least one of the cunning tricks wasn't actually
possible, but that you could get something like it by throwing
continuations with your exceptions.
The effort to fix the JIT core when compiled with optimizations on x86 boxes continues (with a certain amount of discussion of how to use the test modules).
Simon Glover sent a covey of patches, mostly adding tests (yay!) along
with one to fix up and document the .include
assembler
macro. Applied.
Chromatic did some copy editing of the docs and sent in a patch with his fixes. Applied.
Leopold Toetsch has a large patch for the GC system which tries to deal with some of the problems. It's not a complete fix, but Leo thinks it's a start.
Simon Glover noticed that lib/Parrot/PMC.pm is marked as
autogenerated and therefore removed by a make clean
, which would be
okay, but there's no rule in the makefile to regenerate it. Steve Fink
fixed it using Simon's suggested solution.
Dan's fixed the docs for the splice vtable entries in PDD2. Leopold Toetsch promised to implement it.
Michael Lazzaro offers a summary of variables and assignment at cog.cognitivity.com Thanks Michael.
Brent Dax
I manage Configure changes and occasionally work on embedding and extending, the regex engine, misc.c, or whatever catches my fancy.
The end of a day in high school (or sometimes the middle of the day...) :^)
Seriously, I think Perl 6 is an excellent idea. Perl is a great language, but it's been in need of a de-crufting for some time.
Hmm...probably next year sometime. Not soon enough for me to like it, but not late enough to complain about it.
Because it's fun and interesting. And I get paid to manage a Web site, so Perl eq money. And I'm actually taken seriously.
Hubristic hacker who really knows_little.
No, of course not. No need to search this suitcase. Nope, not a bit. The customs dogs must have smelled a doggy treat or something.
Thanks are, of course, due to Leon Brocard for ably filling my shoes for the past couple of weeks and making sure that the summaries got through.
I'd also like to thank Rhys Weatherly and Gopal V for popping up on the internals list. I think it's great to see good communication and cooperation between the different projects working in this field.
Thanks too to my army of crack proofreaders who help to turn the misspelled morass of bad grammar that is my first draft into something that's readable. This week's team was: Chris Ball
The Perl 6 Summary was produced with the aid of GNER tea, the distractions of MAME and 10 Yard Fight and with money from O'Reilly and Associates. If you liked it, please consider giving money to the Perl Foundation at donate.perl-foundation.org and feedback and/or NeXTcubes to me, mailto:[email protected]
The fee paid for publication of this summary on perl.com has been donated directly to the Perl Foundation.