The Perl 6 Summary from 2005-08-24 to 2005-09-11
It's been a while hasn't it?
We'll start as usual with perl6-compiler
This week in perl6-compiler
Changed "??::" to "??!!" in Pugs
Following discussion of the ternary operator in perl6-language, Benjamin
Smith altered pugs to use the new "??!!" syntax.
<http://xrl.us/hjb5>
Meanwhile in perl6-internals
Which 'English'?
Joshua Hoblitt posted a patch to intro.pod fixing a few typos and
wondered whether the docs should be in British or American English.
Apparently the Perl 5 style rule is that British authors shouldn't be
required to write American English, and vice versa, but that a
consistent style within a document is preferred. The consensus so far
seems to be "Any documentation is good so write what's comfortable for
you."
<http://xrl.us/hjb6>
Meanwhile, at the test
Warne just got Trescothick out. 109 for 4
Python PMCs
Sam Ruby, Leo and Chip had a discussion of how to implement python
semantics for parrot. I'm not sure I followed what was going on, but it
looked like good 'crunchy' stuff.
<http://xrl.us/hjb7>
Zcode interpreter release
Amir Karger announced that he'd adopted the Zcode interpreter that Leo
posted in February (having, according to Amir, done the hard parts).
Apparently there's 41 opcodes to do just to get version 3 of the
Z-machine working, and then there's the problem of making Zops into
loadable Parrot ops. He had a few problems with the test suite which got
fixed in discussion.
<http://xrl.us/hjb8>
Pirate refactoring report
Michal Wallace posted an update on Pirate (the python to parrot
compiler). He and Curtis Hall have been taking advantage of a Google
Summer of Code grant to refactor the (Curse! Now Flintoff's out. Caught
& bowled Warne for 8) current mess. Their first step was a generic
transformation module which has apparently made life easier for the
compiler module.
They've also produced a plan in code for how they hope they'll have
things working once the refactoring's finished and asked for comments.
So far comments have not been forthcoming.
<http://xrl.us/hjb9>
<http://xrl.us/hjca>
Tcl in the "leo-ctx5" branch
Will Coleda's been having a crack at getting ParTcl working with the
leo-ctx5 branch and had a few problems. It turns out that he'd tickled a
bug that Leo described as 'a bit non-trivial'. It took him a while, but
it got fixed eventually (Over 10 days, but he did have the excuse of
being at YAPC::Europe for a chunk of that time).
<http://xrl.us/hjcb>
Meanwhile at the Oval
They've gone in for lunch at 127 for 5. Hopefully I'll be able to get
down to some summary writing without being on the edge of my seat for a
while.
Branch Review
Chip posted a review of the "leo-ctx5" branch prior, describing it as "A
significant improvement." The body of the review covers user visible
changes and a few niggles with the current state of the branch. Leo
replied with a few questions and explanations.
<http://xrl.us/hjcc>
GMC release
Nattfodd announced the 'release' of GMC, the generation garbage
collector he's been working on as part of Google's Summer of Code. It's
not quite bug free yet, but the SoC deadline was the 1st of September,
so that's when it got released. Discussion ensued, hopefully helping to
triangulate bugs.
<http://xrl.us/hjcd>
Call for B0rked
Following a discussion with Chip and Leo, chromatic posted a call for
entries in a 'very specific TODO list'. A list of things that should
work, but don't. He contributed a couple himself. Various other
suggestions were offered.
<http://xrl.us/hjce>
Optimizer Documentation
Curtis Rawls spent part of his Summer of Code project wishing there was
better documentation of the Parrot optimizer. So he wrote some. Brent
Royal-Gordon converted it to POD format, and Leo asked for someone to
add it to the repository.
<http://xrl.us/hjcf>
HLL Namespace Design
Matt Diephouse posted a list of namespace features that he thinks are
necessary to support all the target languages and asked for some
comments. He got several, including one from Larry.
<http://xrl.us/hjcg>
Global Destruction
Nicholas Clark had some questions about finalization and destruction in
Parrot. In particular, he asked: "Does parrot make any guarantee that
all objects will be rendered down to bare memory before program exit".
Leo answered and the answer was good enough for Ponie. Huzzah.
<http://xrl.us/hjch>
Meanwhile, at the Oval
Ah... they're back on the pitch... I may be slowing down again...
Meanwhile, in perl6-language
Demagicalizing Pairs
Discussion of Luke's proposal to demagicalize Pairs continued. It turns
out that it's actually a discussion of how to do named argument
calling...
<http://xrl.us/hjci>
"~" and "+" vs. generic "eq"
I don't know about you, but I'm starting to lose track of Perl 6's
'equality' tests. The latest discussion concerns the differences between
"~~" and "eqv". Damian pointed out that we currently stand at 6
different possible tests for 'equality' and wondered if that might not
be slightly too many.
<http://xrl.us/hjcj>
Perl 6 code -- A possible compile, link, run cycle
Yuval Kogman thought it was time to think about how a the Perl 6 on
Parrot linker might eventually look. So he did some thinking aloud.
Discussion ensued, mostly related to the workings of "use" and other
directives that can affect compilation semantics.
<http://xrl.us/hjck>
Binding of array elements
Ingo Blechschmidt had some questions about the workings of the binding
operator. He outlined a list of possibilities along with his
understanding of the semantics. Yuval Kogman and TSa had some ideas, but
nothing from @Larry yet.
<http://xrl.us/hjcm>
Who is @Larry
Speaking of @Larry, Matt Fowles asked who comprises @Larry. According to
Autrijus, "@Larry = «Larry Damian Chip Leo chromatic Allison Hugo Luke
Nathan Dan»", but I have the feeling Dan's retired.
<http://xrl.us/hjcn>
Does list construction create new containers?
Continuing his investigations of semantics, Ingo Blechschmidt had some
questions about the semantics of list construction. Yuval and Juerd had
some suggested answers.
<http://xrl.us/hjco>
Using lists 'containing' arrays as lvalues
More questions from Ingo, more suggestions from Yuval and Thomas Sandlaß
this time. There was even an answer from Larry.
<http://xrl.us/hjcp>
How do you say "another_sub(@_)" in perl 6?
Yuval wondered how to pass arguments through from one sub to another in
Perl 6. My mailbox appears to be missing a few replies so I'm not
entirely sure how the thread went. I don't think there was anything on
the subject from @Larry though.
<http://xrl.us/hjcq>
User defined autovivification
Yuval Kogman thinks code like this is ugly:
($index_by_x{$thing->x_value} ||= Set::Object->new)->insert($thing);
Frankly, I agree with him (how could I not?)
He suggested a couple of possible ways of avoiding such ugliness in Perl
6. My favourite was probably:
my %hash will autovivify { Set::Object.new };
However, I'm not sure that this is something that needs to be in the
language core; it seems to be the sort of thing that can be implemented
reasonably simply in a CP6AN module.
<http://xrl.us/hjcr>
Manuthreading
Luke is trying to get the useful:dangerous balance inherent in Junctions
sorted out. To that end, he proposed a new way to do autothreading that
doesn't use junctions at all. Discussion ensued, mostly to do with where
to fit the semantics in the syntax.
<http://xrl.us/hjcs>
Operator sub names that are not special
Luke tried to make people's heads hurt with this sample code:
sub foo(&infix:<+>) { 1 + 2 }
sub bar($a, $b) { say "$a, $b" }
foo(&bar); # "1, 2"
I think everyone but Yuval Kogman was too shocked to comment.
<http://xrl.us/hjct>
"@array = $scalar"
Ingo continued his mission to understand assignment semantics by asking
about assigning a scalar to an array. The thread drifted slightly,
moving onto consideration of such hypothetical(?) operators as ",=",
"&=" and "|=". One of those is probably more hypothetical than the
others.
<http://xrl.us/hjcu>
"no 6;"
Rafael Garcia-Suarez thought it would be useful to be able to put "no
6;" at the top of Perl 5 modules that it wouldn't make sense to port to
Perl 6. In order for this to work effectively, he thought it would be
best if Perl 6 would at least die correctly with a useful error message.
He asked p6l for comments. Apart from asking if supporting "no 5" would
mean we'd have to support Perl 4, there weren't any.
<http://xrl.us/hjcv>
"for $arrayref {...}"
Another question from Ingo. Another answer from Juerd with commentary
from Luke.
<http://xrl.us/hjcw>
WWW::Kontent 0.02 is released
Another of our Summer of Code interns, Brent Royal-Gordon announced the
0.02 release of WWW::Kontent, a content management system written in
Perl 6 and executable in Pugs. As Brent says, it's not ready for
production, but it seems to be ready for serious play. From the release
notes:
"Part of the purpose of this project was to test Perl 6, and I'm happy
to report that it passed with flying colors. Perl 6 feels like a
much-enhanced Perl 5, with all the wrinkles removed and very few new
ones added. It seems to be a very solid design, and is a joy to program
in."
I've been saying that this would be the case for ages now. It's good to
see that Brent's experience here bears that out.
<http://xrl.us/hjcx>
"&multisub.arity"
And another question from Ingo. This time he wanted to know about the
arity of multi subs. The discussion got rather complicated.
<http://en.wikipedia.org/wiki/Arity> - The meaning of arity
<http://xrl.us/hjcy>
Multi scoping
Luke showed an example of a seemingly simple multi sub declaration that
ended up creating an infinite loop. He asked for suggestions about
fixing it. He and Yuval worked some stuff out.
<http://xrl.us/hjcz>
Lambda Calculus in Perl 6
Dan Kogai noted that its way easier to do Lambda Calculus things in Perl
6 than it was in Perl 5. He even went so far as to claim it was even
easier than doing the same thing in Scheme.
<http://xrl.us/hjc2>
Changing "??::"
Thomas Sandlass thought that making "::" unambiguously be used as a
symbolic sigil was worth changing the ternary operator to "??//". Almost
everyone agreed that replacing "::" wouldn't be a bad thing, but that
"//" wasn't the right replacement. We ended up with the ternary operator
becoming "??!!".
<http://xrl.us/hjc3>
"\(...)"
Another of Ingo's questions, this time about the behaviour of "\(...)"
spun off into a rather complicated discussion that I'm afraid I'm not
going to attempt to summarise in more detail than that.
<http://xrl.us/hjc4>
Packages, Module and Classes
Stevan Little is currently wrestling with the Pugs MetaModel and had
some questions about the workings and interrelationships of Packages,
Modules and Classes. He and Larry sorted things out.
<http://xrl.us/hjc5>
Parsing indent-sensitive languages
Dave Whipp had some questions about parsing a Pythonesque language using
Perl 6 rules. Much discussion ensued with possible extensions to Perl 6
rules being suggested. Then Damian pointed out, with appropriate rules,
that you don't need any extensions, you can parse such languages
already.
<http://xrl.us/hjc6>
Back at the Oval
McGrath just bowled Kevin Pietersen for 158. It's looking awfully like
we've won The Ashes.
Item and slurpy
Juerd wondered if 'item context' and 'slurpy context' were official
terms now. Larry thought not, preferring item and list context.
<http://xrl.us/hjc7>
Sequence points, undefined behaviour
Nicholas Clark wondered if Perl 6 will have any documented notion of
things like sequence points, undefined behaviour, etc. Will it fix the
order in which function arguments are evaluated and all those other
things it's useful to know. Warnock applies.
<http://xrl.us/hjc8>
Acknowledgements, apologies and everything else
Ah... sorry for the lack of recent summaries. Sorry for being distracted
by the cricket, but it's been a bit tense for most of the day.
Help Chip
<http://geeksunite.org/> -- Chip still needs help.
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/hjc9>
--
Piers Cawley <[EMAIL PROTECTED]>
http://www.bofh.org.uk/
