The Perl 6 Summary of the week ending 20031019
Lumme! Another week, another summary.
Every week (almost) we start with the perl6-internals list, so here
goes.
An Evil task for the interested
Our Glorious Leader, Dan Sugalski, last week asked for volunteers to
work on making ordered destruction work. (Ordered destruction is where
the system tries to ensure that 'parent' objects get destroyed before
any of their children). Jeff Clites announced that he'd got a partial
implementation working.
Neither Leo Tötsch nor Jürgen Bömmels were sure that the approach Jeff
was taking would be the Right Thing in the long run, proposing instead a
more general iterator mechanism.
http://xrl.us/x8k
Perl 6 Sub calling
Bringing the perl6 compiler (in languages/ back to live, Steve Fink has
committed a 'rather large' patch which implements a subset of the
Apocalypse 6 subroutine signature rules. The implementation is
apparently very ad hoc and shouldn't be regarded as the final word. But
it looks like a very good start to me.
http://xrl.us/x8l
Website timeliness
Responding to Matt Fowles' observation that the parrot website is rather
behind the times, Robert Spier let slip that there would soon be a
revised website that will be easy for everyone to send patches to, and
which would be much easier to have multiple maintainers of different
areas of the site.
Of course, there are still a few 'technical chunks' that need to get
finished before it's ready to unveil, but it's good to know that work
continues in this area. Thanks Robert.
http://xrl.us/x8m
http://xrl.us/x8n -- Mike Scott's Parrot Wiki
Dynamic oplibs
Chances are, you've never really needed a "fortytwo" operator, or even a
"what_do_you_get_if_you_multiply_six_by_nine" operator, and you
certainly don't need them cluttering up the parrot core. Which is why
Leo Tötsch has implemented those ops as a dynamically loadable ops
library.
Admittedly, you're highly unlikely to load this particular ops library,
but the underpinning tools for dynamic loading of ops libraries are new
and potentially very useful.
Rather later in the week, once he'd got dynamic loading of ops working
in all the runtime cores, Leo posted an 'intermediate summary' which
explains how things work.
http://xrl.us/x8o
http://xrl.us/x8p
Oplips, pmclibs, function libs
Dan has been thinking about the problems that can arise with dynamic
loading. One issue is that, if you have separate files for each PMC
class, opcode library and parrot function library, things get unwieldy
very quickly, and if you're not careful you'll exhaust the OS file
descriptor pool. Which would be bad. So, he asked for a sanity check
before going on to work out a scheme for bundling libraries into larger
files. Leo agreed that Dan was talking sense, so I expect we'll be
seeing some design in this area soon.
http://xrl.us/x8q
Instantiating objects
It's been a busy week on the parrot front for Dan. On Wednesday he
outlined his thinking on instantiating objects, with the aim of getting
single inheritance objects up and running. This sparked a good deal of
discussion, but nothing was actually agreed.
http://xrl.us/x8r
Redoing IMCC macros
Surprisingly, Jürgen Bömmels opened up a can of worms when he redid
IMCC's macro support to use a hash lookup instead of a linear search
through an array. This sparked a good deal of discussion about the right
scoping, which hash implementation to use, and whether IMCC should be
closely entwined with the interpreter.
http://xrl.us/x8s
Fixed opcode numbering infrastructure
Dan checked in a patch to fix opcode numbers for the core ops,
deliberately breaking the JIT in the process. Leo wasn't happy. After a
bit of back and forth, we now have fixed opcodes, but the implementation
isn't quite what Dan originally did.
There was also some discussion of how many opcodes really needed to be
fixed; after all, in the presence of dynamically loaded oplibs, you
can't nail every opcode down. Leo worried that dynamically loaded oplibs
don't play well with JIT, and making it work would probably need a total
rewrite of the JIT core, but Jürgen didn't think it was all that bad.
http://xrl.us/x8t
Applying the Pumpking Patch
$ patch RESPONSIBLE_PARTIES
6c6
< Release pumpking Steve Fink
---
> Release pumpking Leopold Toetsch
In other words, Steve Fink has stepped down from the rôle of Parrot
Pumpking and handed the his mantle on to Leo "Pumpking Patchmonster"
Tötsch. I'm sure I'm not alone in wishing to thank Steve for his
sterling work as our release manager. Nor, I'm sure, am I alone in
wondering where Leo finds the time.
http://xrl.us/x8u
Bounds checking in extension API
Simon Glover wanted to know what sort of bounds checking was/will be
done by the extension API's register access functions. At the time of
his writing they didn't do any, which meant you could trivially cause a
buffer overflow in your extension by accessing an illegal register
number, like 42. Dan said that what needed to happen is for the access
functions to do bounds checking and to throw an exception on an illegal
register number. Which wasn't quite as straightforward as he thought.
http://xrl.us/x8v
Meanwhile, in perl6-language-subs
What's that you say? You've never heard of perl6-language-subs? Shame on
you. Actually, I'd forgotten about perl6-language-subs but, judging by
the messages I've seen on the list since I started writing the
summaries, it would appear that it's a mailing list where students can
ask the Perl 6 community to do their computer science homework for them.
I don't expect to be covering this list any further.
Meanwhile, in perl6-language
The Wall Returns
Larry returned from what sounds like a horrible couple of months in
hospital and answered Luke Palmer's awkward question about block returns
from a couple of weeks ago.
http://xrl.us/x8w
Acknowledgements, Announcements, Apologies
Tuesday is no longer the new Monday. Wednesday is the new new Monday.
If you found this summary valuable, you might like to consider one or
more of:
* Get involved. Parrot (and Perl 6) needs programmers, authors, users
and other interested parties. Join the mailing lists and start to
contribute. (Check http://dev.perl.org/perl6/ and
http://www.parrotcode.org/ as good starting points).
* Support Larry, Dan, Damian and company by donating to the Perl
Foundation at http://donate.perl-foundation.org/. I hate to think
what the Wall family medical bills must be like at the moment.
* Give me lots of lovely feedback at [EMAIL PROTECTED], you
know you want to.
