The Perl 6 Summary for the Week Ending 20020929
Okay, this is my last summary before I take a couple of week's holiday
away from any form of connectivity. Will I cope? Can my system stand
going cold turkey? Can you live without my summaries?
Luckily, Leon Brocard has been volunteered to step into the breach and
produce summaries for the next couple of weeks.
Oh yes, due to my being a lazy swine and not reading release notes,
combined with a new version of Spamassassin no longer delivering mail by
default (now it silently drops mail on the floor in cases where it had
previously just delivered the mail), I may be missing some messages from
this week. Sorry.
We'll kick off, as usual with happenings on the internal list:
Of Variables, Values and Vtables
Dan stopped travelling (for a while at least), and listed the current
short term goals for Parrot. They are:
* Finish up the calling convention changes
* Spec the PMC changes
* Spec the vtable changes
* Get exceptions fully defined and a preliminary implementation
and promised the variable/vtable stuff in the `next day or so', with the
calling convention stuff a little earlier or later. Leo Toetsch offered
some his thoughts on vtable methods for _keyed opcodes.
http://makeashorterlink.com/?Z31D146F1
http://makeashorterlink.com/?L22D226F1
IMCC 0.0.9.2
Leopold Toetsch provided a patch which `fixes all currently known
problems [with respect to] IMCC/Perl6'. Andy Dougherty had some problems
with the patch dumping core, possibly because of platform specific
issues, and Steve Fink realised that there was an overlap between this
patch and one he'd been working on. The patch has not yet been applied,
but work continued.
http://makeashorterlink.com/?L23D326F1
Fun with intlists
Leopold Toetsch showed some benchmarks of intlist against PerlArrays,
the difference is stunning. The intlist based test is some ten times
faster than PerlArray, with most of PerlArray's time being spent
allocating memory. Leo suggests using intlist as the PerlArray base
class.
Having got bragging rights for one speed up, Leo sent in a second patch
which gave *another* ten fold performance boost. Sean O'Rourke had a few
questions about performance in typical usage and wondered if, we
shouldn't look at using borrowing from SGI's STL implementation of a
dequeue (double ended queue). Leo was ahead of him there; his second
patch was already using the trick Sean had suggested.
http://makeashorterlink.com/?E34D126F1
http://makeashorterlink.com/?L25D516F1
Functions in Scheme
Jürgen B"ouml"mmels sent a pre patch which gets Scheme functions
working. It's built on top of an early version of Sean O'Rourke's
scratchpad.pmc, so be careful applying the initial patch. Sean hoped
that it would be be easy to reconcile Jürgen's changes to the scratchpad
pmc with the changes he'd made since he sent Jürgen his early code.
Jonathan Sillito asked why the scheme interpreter maintained its own
environment stack rather than use the "pad_stack". Apparently the
current pad_stack is very closely tied to Sub.pmc, which doesn't quite
offer the semantics needed for scheme functions. Also, the pad_stack
makes it tricky to implement "set!" and "define" correctly.
Dan chimed in asking everyone to hash out what they needed from
scratchpads and lexical variables; once we have that nailed down it
should be easy to get everything designed and implemented reasonably
quickly, so Jürgen and Sean came up with a list between them.
http://makeashorterlink.com/?O16D116F1 -- The patch
http://makeashorterlink.com/?B27D126F1 -- Its description
Perl6 on HP-UX 11.00
H Merijn Brand was having trouble getting Perl 6 to work on HP-UX. It
was initially thought that this was a problem with the version of perl
he was using, but was eventually tracked down to a problem with "make
test"; the tests passed when Merijn did "perl6 --test". However the
thread also covered making sure that the Perl6 build process rebuilt the
Grammar if appropriate. There's also a theory that there's a problem
with IMCC generating .pasm files.
Leopold Toetsch put his hand up for causing the problem, and submitted a
patch to fix things. Applied.
http://makeashorterlink.com/?S18D256F1
http://makeashorterlink.com/?O39D216F1
The status of Leopold Toetsch's patches
Leo wondered what's happening with the pile of patches he's submitted
this week. At the time he made the post, he had 15 patches outstanding
(or is that `outstanding patches'?) and, as a result several of the
patches were applied. Steve Fink voted that Leo should be given commit
access to CVS and Leo was grateful for the vote of confidence.
Leo later sent in yet another patch for intlist, which after a short
quibble from Tom Hughes, and a correction from Leo, was applied.
http://makeashorterlink.com/?G4AD236F1
http://makeashorterlink.com/?M2BD326F1
Of PMCs Buffers and memory management
Worker of the week, Leo Toetsch posted a bunch of questions about PMCs,
Buffers and their associated memory management. Firstly, he wondered why
there was a separation between the two. He commented that `If PMCs and
Buffers are unified, it should be possible to mark [during a GC run] in
one recursive process'. And there's the rub; we don't like recursion.
PMCs are structured in such a way that a PMC tree can be walked in
iterative fashion, which means that GC can be done in pretty much
constant memory. Leo had a bunch of other questions, that were mostly
answered by Mike Lambert, which drew supplementary questions from Leo.
Both Mike and Leo agreed that the changes needed to Parrot for
unification would lead to massive patches; but that's not a reason for
*not* doing the work.
http://makeashorterlink.com/?W2CD626F1
http://makeashorterlink.com/?U5DD126F1
Add Stone Age Exception Handling
This should possibly really go in the 'In Brief' section because there
was only one post in the `thread'. But it looks like an important post.
Brent Dax sent in a patch which `adds a very, very rudimentary form of
C-level exception handling' to parrot. Brent Reckons that brings parrot
up to slightly better than `homo erectus' quality exception handling.
http://makeashorterlink.com/?T5ED546F1
Meanwhile, in Perl 6
I can't remember who it was christened this week's monster thread `Paren
Madness', but they weren't wrong. The `Here, we can build a list like
this...' thread continued on its merry way. I'm afraid I pretty much
stopped reading once it became apparent that the only thing that was
going to stop the madness was Larry making a pronouncement. Eventually
Dan stepped up and asked if someone could summarize the discussion,
maybe with a few possible conclusions, and then leave it for a while
'til Larry got back. Luke Palmer wrote it up and offered a suggestion
which looks at first glance to be sane, and which seemed to be well
liked.
http://makeashorterlink.com/?D1FD256F1
http://makeashorterlink.com/?Y50E416F1
For loop and streams
In pretty much the only other substantial thread of the week,
`[EMAIL PROTECTED]' had some problems with the new "for" loop using
multiple counters, and wondered if this was because of problems with the
current Perl6 implementation, or because of problems with his
understanding. It turned out that it was a problem with Sean O'Rourke's
understanding when he implemented the Perl 6 grammar; he'd missed
something in the appropriate Apocalypse. There also seems to be a
problem in that the current behaviour is mostly defined with hand waves,
which is great when you're doing the broad brush design, but less great
when you're trying to implement the language.
http://makeashorterlink.com/?V21E116F1
In Brief
Leopold Toetsch patched packfile.c to stop monkeying with the internals
of key structures.
Parrot T Shirts, based on Andy Wardley's parrot logo design, are now
available from Cafe Press at http://makeashorterlink.com/?F22E226F1,
any proceeds go to YAS/TPF.
Simon Cozens found, and patched a problem with IMCC's `ostat' structure,
which clashed with a structure in Darwin's stat.h.
Leopold Toetsch has been playing with using Doug Lea's memory allocator
(see http://makeashorterlink.com/?D23E216F1) in Parrot. Apparently it
makes `life' run faster, but appears to double the memory footprint.
Steve Fink sent in some patches for IMCC, Leopold Toetsch did some
cherry picking and released an integrated patch.
Erik Lechak wondered if there was a getting started guide to parrot, and
if there wasn't, how should he go about writing one? My tip: Do it, use
the tools you prefer to make the kind of guide you would have welcomed
finding when you first came to parrot. Just don't use proprietary
formats. Heck, it's how I started writing these summaries.
Who's Who in Perl 6
Who are you?
Piers Cawley
What do you do for/with Perl 6?
I write the summaries every week, and try and contribute to
perl6-language and perl6-internals when they're discussing things I
know about.
Where are you coming from?
I've been a happy Perl user for since around 4.036, initially using
it as a shell and awk replacement for system administration tasks,
then moving over into a programming rôle where I got heavily into OO
Perl. As so many others have said, Perl 5 fits my brain better than
anything else I've been paid to do, but Perl 6 offers the chance to
make that fit much closer.
When do you think Perl 6 will be released?
Sooner than we all think. Later than I want.
Why are you doing this?
Someone had to. I missed Bryan's summaries and decided that, if
nobody else was going to volunteer it might as well be me.
You have 5 words. Describe yourself.
Just another opinionated Perl hack.
Do you have anything to declare?
I've run out of answer sets to this questionnaire. C'mon people,
your summarizer needs you.
Acknowledgements
Thanks to Piers Cawley, for taking time out of his massively busy
schedule to answer the questionnaire; to Leon Brocard, for not squawking
too loudly when he got volunteered to do the next two summaries; to Leo
Toetsch, for a fantastic number of patches this week; to Simon Cozens,
for coming back to Perl 6; to the lovely Gill, for continuing to put up
with me, day in, day out...
Hmm... check out the Oscar speech.
I'm trying an experiment this week, community proofreading. I'll run the
speelchucker over this summary and release it to the ravening masses.
Who knows, maybe it'll make sense. It does at least have the right date
at the top of the page.
Once more, if you think this summary has value send money to the Perl
Foundation (http://donate.perl-foundation.org) and feed back and/or
T?iBooks to me, <mailto:[EMAIL PROTECTED]>. As usual, the fee paid
for publication of this summary on perl.com has been donated directly to
the Perl Foundation.
--
Piers
"It is a truth universally acknowledged that a language in
possession of a rich syntax must be in need of a rewrite."
-- Jane Austen?
