The Perl 6 Summary of the week ending 20031102
It's Monday morning, the croissants have been baked, the focaccia is
glistening with all the extra virgin olive oil I poured on it as it left
the oven and, in the airing cupboard, a raisin borodinsky slouches
towards full proof (thought at the rate it's currently rising it'll
probably be Tuesday before I can bake it off), what better time could
there be to pause and write a summary?
So, I'll kick off with perl6-internals because, well, it's on the
summary checklist (which goes something like: 1. Wibble about the
weather or something before; 2. Start with perl6-internals; 3. Continue
with perl6-language if it saw any traffic; 4. Make announcements,
suggest people give money to the Perl Foundation; 5. Make sure Leon
Brocard gets a mention; 6. Aspell; 7. Mail PODs to http://perl.com and
a text version to perl6-announce; 8. Profit!)
NULL Px Proposal
Right at the end of the previous week, Melvin Smith suggested having the
initial 'empty' PMC registers all point at a global PMCNull which would
throw an exception if you tried to invoke any of its methods. Which
sounds weird, but it does mean that you get a real exception instead of
a segfault, and exceptions are so much more trappable. Dan liked the
idea.
Melvin later posted a patch implementing the idea, which Leo TÃtsch
fixed up slightly an applied.
http://xrl.us/2w8
http://xrl.us/2w9
Parrot Calling Convention Confusion
Steve Fink is having problems using an unprototyped call to a prototyped
function, which he thinks is a reasonable thing to do (and I think I
agree with him; I can imagine cases where you have a function pointer or
something where you don't know its exact prototype, but you do want to
make a call to it so you'd be forced to make an unprototyped call.).
Melvin Smith disagrees with him. Steve then went on to point out that
he's still getting failures when the function is both declared and
called in an unprototyped fashion. According to Leo, this is because
unprototyped returns are neither defined nor implemented. Which is odd
really -- I thought they were exactly the same as an unprototyped call,
but you invoke the return continuation (P1) instead of P0, the other
registers are set up exactly as if you were making an unprototyped
function call.
http://xrl.us/2xa
A clash of symbols
Arthur Bergman, Ponie stablemaster, popped up to point out that
definitions like
#define version obj.version
(found in include/parrot/pobj.h if you're interested) did some scary
things to "Perl_utilize" in the Perl 5 core. Steve Fink stuck his hand
up to being the person who added the version field (which is apparently
rather handy if you're debugging the Garbage Collection (GC) system. Leo
fixed things by applying a "s/version/pobj_version/g" patch.
http://xrl.us/2xb
Storing external data in PMCs
Arthur popped up again asking for help with implementing a Perl5LVALUE
PMC. It turns out that the API doesn't quite support what he needs.
After a certain amount of discussion of various options Arthur proposed
a "Parrot_PMC_attach_data(Parrot, PMC, *void)" extension to the API. He
didn't *quite* get what he wanted, but he got something very like it
later in the week.
I did like Arthur's reasons for starting the serious Ponie effort by
working on Perl5LVALUEs though: "[because] it is so obscure that it's
hardly used anywhere and is limited to a few small areas in the core".
http://xrl.us/2xc
Screaming Pumpkins Ahoy!
On Monday, Leo declared that yes, Melvin Smith's proposed Halloween
'Screaming Pumpkin' Parrot release would be happening. Various people
promised extra goodies, and a few problems were sorted out with some
platforms.
Features were frozen on Wednesday and Parrot 0.0.13 "Screaming Pumpkin"
was released upon a cowering world at 2003103114:11:46 precisely. For
all the astonishing speed of the release cycle, there's a lot of good
stuff to be had in the screaming pumpkin, check out Leo's announcement
for details.
http://xrl.us/2xd
http://xrl.us/2xe -- Leo's announcement
Header Dependencies
JÃrgen BÃmmels wasn't entirely happy with the way Parrot's headers are
set up. Apparently there are some nasty dependency (and crypto
dependency) issues. He proposed fixing up the headers as much as
possible to eliminate these issues. Dan and Leo thought it would be
nice, but Dan thought there wouldn't be that much point in doing it as
things would probably decay, and pretty much everything internal should
just be using parrot.h, and everything external should be using extend.h
or embed.h.
http://xrl.us/2xf
Tinderboxen
JÃrgen BÃmmels triggered a quick bout of tinderbox fixing, as various
different hardware experts helped to figure out why several of the
tinderboxes weren't building and testing successfully. Jonathan
Worthington submitted a few patches to clean up the various Win32
warnings. David Robins submitted similar patches to clean up some
Solaris warnings.
http://xrl.us/2xg
Wrapping C/C++ libraries
Anuradha Ratnaweera asked a bunch of questions about how Parrot and Perl
6 would interface to external C and C++ libraries. The Leo and Dan
provided the answers.
http://xrl.us/2xi
Broken Windows
(Sorry about the heading, I couldn't resist). Jonathan Worthington
reported some breakage of NCI on Win32. He and Leo worked through the
issues in search of a fix.
http://xrl.us/2xj
Garbage-collecting classes
Luke Palmer responded to the comment in last week's summary about the
way to instantiate an object in class Foo being:
new P5, .Foo
He worried that, because classes are now simply integers, there was no
way to garbage collect class objects if anonymous classes were used
heavily. Jeff Clites, Leo and Dan all rushed to reassure him.
http://xrl.us/2xk
Parrot IO Fun
On Thursday, Melvin Smith announced that Parrot had fetched its first
web page. Your parrot can fetch webpages too, just update to the latest,
check out examples/io/http.imc and the world is yours. Everyone made
impressed noises.
http://xrl.us/2xl
Melvin Smith, tease of the week
Melvin announced that, in his personal copy of Parrot he has most of the
Class metadata declaration support working, but that he wouldn't release
it 'til after the Screaming Pumpkin release. If it's as good as he
promised, I guess we can wait.
http://xrl.us/2xm
Character classification functions
Noting the presence of the "is_digit" function, Peter Gibbs wondered if
it would be useful to have a set of "is_foo" functions, or better to
have a single "is_ctype" function with an enum parameter. He preferred
the "is_ctype" option, and set about implementing it. Ever the speed
demon, Dan thought it best to have a reasonable set of "is_foo"
functions for 'common' chartypes and a fallback "is_ctype" function for
the rest. Once they were all wrapped up in sensible macros that would
mean that you didn't have the possibility of a very small speed hit
getting multiplied up in the middle of a tight loop, but the programmer
wouldn't have to worry about which types were checked in which fashion.
http://xrl.us/2xn
Moving to a new PMC compiler
Leo TÃtsch posted a patch to switch Parrot over to using pmc2c2, the new
version of the PMC compiler, but didn't commit it because his Makefile
was playing up. He asked for some help to fix that before the patch
could be committed.
http://xrl.us/2xo
Summary suggestion
Ron Grunwald suggested that it might be a good idea to include a
glossary with each summary explaining what IMCC, PMC and PIR stand for
(um... Incredibly Magnificent Compiler Compiler(?), Parrot Magic Cookie
and Parrot Intermediate Representation(?) respectively) and maybe giving
some explanation of other bits of Parrot jargon. Which is a jolly good
idea. But laziness dictates that, instead I point you all at
docs/glossary.pod which, following a gentle nudge on the mailing list,
covers the above acronyms and more (but sadly some of 'em are missing
from the Screaming Pumpkin release).
http://xrl.us/2xp
Meanwhile, in perl6-language
There was some real traffic. With questions. And Answers! What is the
world coming to? Admittedly, there were only 10 posts in the week, but
it's the *quality* that counts.
Alternately named arguments
Remember last week, when Luke "Edgecase finder general" Palmer asked
about named return values and made David Storrs boggle? This week he was
answered. By Damian. And Larry. Any question that elicits a "Please,
no!" from Damian has got to be a good question methinks.
The question revolves around the statement in Apocalypse 6 that a list
on the left hand side of a binding operator (":=") is interpreted in the
same way as a function signature. Which means that you can use 'named'
binding:
(who => $name, why => $reason) := (why => $because, who => "me");
# ($name == "me") && ($reason = $because)
What elicited the "Please, no!" was Luke's logical conclusion that this
could also mean that you could do:
(+$name, +$id) := getinfo();
and the unary "+" would be treated as a 'named only' marker in the same
way it would be in a function signature.
Interestingly, Larry was less convinced that this was inherently a bad
thing, though he did propose that, under most forms of stricture that it
should only work in the case of:
my(+$name, +$id) := getinfo();
because the "my" helps the reader to realise that "+" may not be in
Kansas any more without having to reach the ":=" and then reinterpret
everything that went before. (If you've heard Damian, Allison or
possibly even Larry talking about Perl 6, you've almost certainly come
up against the concept of "end weight"; this is an example).
http://xrl.us/2xq
State of the Conway
It's been a while since Damian said anything in perl6-language, so David
Wheeler welcomed both him and Larry back. Damian thanked him, and posted
a short status report. While he's not been in quite the same state as
Larry, "mild influenza and a little light pneumonia" don't sound like a
barrel of laughs either. Anyway, he's back on the case when he can spare
the time from putting food on the table.
http://xrl.us/2xr
Questions about currying
Joe Gottman had some questions about currying. Luke Palmer and Jonathan
Scott Duff answered 'em. I'm getting quite good at this summarizing
malarkey aren't I?
http://xrl.us/2xs
Acknowledgements, Announcements, Apologies
Whee! Monday is this week's Monday! What's the betting I can keep it up?
Those of you who've been reading this summary since almost the beginning
will remember that I copped the basic 'chunks of text followed by a link
or two' format/structure(hah!) of these summaries from NTK. Well, this
Friday's NTK had some coverage of the state of Larry and Damian's health
in their HARD NEWS section (http://www.ntk.net/2003/10/31/).
If you found this summary valuable, please consider one or more of:
* Join in! The project needs people. http://dev/perl.org/perl6/ and
http://www.parrotcode.org/ are good starting points for
information.
* Chip in! Money helps keep the wheels turning, programmers like
Larry, Dan and Damian have families to feed and medical bills to
pay, finding that money takes time away from getting Perl 6 out of
the door. By donating money to The Perl Foundation
http://donate.perl-foundation.org/ you can help.
* Chime in! It's always good to get direct feedback from readers. Drop
me a line to let me know what you think at
<[EMAIL PROTECTED]>, I promise I'll reply (assuming it's
not spam, in which case I shall simply wish recurrent hemorrhoids on
you).
