The Perl 6 Summary of the week ending 20031109
Traditionally this paragraph concerns itself with a few words on what
I've been up to before finally settling down to get the summary written.
But despite the fact that it's nearly four o'clock, it's been one of
those days where I seem to have done almost as much as Leon Brocard
generally does to warrant a mention each week.
So, here's what's been happening in perl6-internals to make up for the
lack of guff about breadmaking or whatever. (If you're interested, the
raisin borodinsky I mentioned last week was an unmitigated disaster. The
focaccia was fabulous though).
New glossary entries
Gregor N. Purdy has added a few entries to the Parrot glossary, so if
you've been bursting to know what PIR, IMCC and other Parrot specific
clusters of capitals stand for, check out docs/glossary.pod in the
parrot distribution.
http://xrl.us/3pv
String Encodings hurt my head!
Peter Gibbs is attempting to implement the DBCS encoding (whatever that
is) and has discovered that he can't implement "skip_backward" for it
because of the mixture of 1-byte and 2-byte characters. He offered seven
suggestions for the right thing to do at this impasse.
Michael Scott didn't have any suggestions about the Right Thing, but he
did point to a page on his very lovely Parrot Wiki which discussed most
things Unicode for parrot, and made a plea for Dan (or whoever) to
produce a Strings PDD.
http://xrl.us/3pw
http://xrl.us/3px - Michael's WikiWord
Perl 6 patches
Allison Randal posted a couple of patches to the current (very) mini
Perl 6 that comes with Parrot (in languages/perl6. A little later in the
week, Joseph F. Ryan contributed a Perl 6 patch. It's good to see this
receiving attention again.
http://xrl.us/3py
Documentation
Nick Kostirya wondered why docs/parrot_assembly.pod appeared to be
simply an old version of docs/pdds/pdd06_pasm.pod. He also worried that
docs/ops/ appeared to be empty in the 0.0.13 release of Parrot. Dan
noted that both of the parrot assembly docs were wrong, and that what
would probably happen would be that the PDD would be updated and
docs/parrot_assembly.pod would be retired. Jürgen Bömmels said that the
empty docs/ops was because during the Great Move, the Makefile that
generated those POD files didn't get updated to cope with the new
location of the .ops files. Nick wondered which other POD files might be
going away so he'd not have to go through the process of translating
obsolete docs into Russian.
http://xrl.us/3pz
http://www.parrotcode.ks.ua/docs -- Why can't I type in Cyrillic?
From the "Interesting, but is it useful?" department
Melvin Smith has been playing with an uncommitted version of "invoke"
which allows you to invoke a function by name not address. He outlined
the ideas behind it (and the workaround to make it play nice with the GC
system), but wondered if it was actually of any use. Dan and Leo both
agreed that it wasn't because of issues with threading and the JIT.
http://xrl.us/3p2
Freeze/thaw data format and PBC
Leo Tötsch is working on the data serialization/deserialization (aka
Freeze/Thaw) system discussed over the last few weeks. He wondered if
there were any plans for the frozen image data format. Leo's plan is to
use PBC constant format (with possible extensions) so things integrate
neatly into bytecode. Dan had a bunch of comments, but the PBC based
format idea seemed to be well received, with the caveat that it should
be a 'dense' format.
http://xrl.us/3p3
Opening files on other layers
Jürgen Bömmels asked for comments on a patch for opening files on
different layers which had a few issues that he felt needed clarifying.
He and Melvin Smith spent some time discussing things.
Apologies for not doing a better job in summarizing this thread, but I'm
hamstrung by not quite knowing what 'layer' means in this context.
http://xrl.us/3p4
Parrot Has PHP
Okay, so the subject line's not quite true (yet), but who could resist
the recursive acronyminess of it? Anyhow:
Thies C. Arntzen and Sterling Hughes, core PHP hackers, popped up to
discuss the work they're doing on porting PHP to Parrot. Specifically,
they've hit a performance snag where PHP's typeless nature meant using a
PMC where they would rather be using a native type for speed. Thies
proposed a new datatype to get 'round the issue.
The general response was "Hey! Fabulous! Someone's making a serious
effort to port a real language to Parrot! But that new type suggestion
is just reinventing the PMC. Oh, and if you could change your generated
code slightly you'd get much faster execution".
It's definitely fabulous though.
http://xrl.us/3p5
http://www.edwardbear.org/pap.pdf -- Thies and Sterling's presentation
"newsub" and implicit registers
Melvin Smith was concerned about the version of "newsub" that implicitly
sets P0 and P1, which can give IMCC's register tracking code something
of a headache. He proposed getting rid of the implicit version and
simply using IMCC to hide things. Leo agreed that the implicit form of
"newsub" wasn't really necessary, but pointed out that there were plenty
more ops out there that had implicit registers that IMCC needed to
track. Leo has a patch in his tree that deals with the issue.
http://xrl.us/3p6
HASH changes
Jürgen Bömmels wasn't entirely happy with some recent changes to HASH in
src/hash.c which make the hash tests fail. Nor was he happy with the
asymmetry of "hash_put" and "hash_get", where you "hash_put" a "void
*value" but "hash_get" back a "HASHBUCKET". Leo apologised for breaking
the tests, but defended the asymmetry because it allows for
distinguishing between a value of NULL and a nonexistent key. Jürgen
wasn't impressed, sometimes the ambiguity is exactly what you want.
Jürgen ended up submitting a patch which implements a new, extended hash
querying API:
HashBucket *hash_get_bucket(...);
void *hash_get(...);
INTVAL hash_exists(...);
http://xrl.us/3p7
NCI broken on Win32
NCI, the Native Call Interface, tries to help its users by adding the
appropriate 'loadable library' extension to any library it's asked to
load. This turns out to be the wrong thing to do when you're trying to
use the NCI from Win32, where there's more than one possible extension
for a loadable library (this turns out to be true for Mac OS X as well).
Jonathan Worthington let slip the fact that he was working on a library
to give Parrot access to the entire Win32 API, and that this would
involve loading a file with a .drv extension, which isn't currently
possible with Parrot on Win32.
The catch is that, in a lot of cases, you need to be able to leave the
extension unspecified because different Unix like OSes use the same
basic library name, but a different extension. (For instance, a Linux
box uses '.so', and OS X uses '.dynlib'). Leo proposed a workaround of
only adding the default extension if the file name didn't already
include a . in the filepart. Jonathan thought that sounded workable, but
suggested that simply trying to load the library with the name as given,
then trying with the default extension and only if that fails throwing
an exception, but Leo thought that that would slow down opening
libraries quite substantially.
http://xrl.us/3p8
Regular expressions
It's been a busy old week this week. First we hear of an effort to port
PHP to Parrot, and then Stéphane Payrard announces that he's started
working on implementing Perl 6 Regular expressions. Which is nice.
http://xrl.us/3p9
Meanwhile in perl6-language
Nested modules
Luke Palmer noted that, as with Perl 5, there was no need for modules
named Foo and Foo::Bar to be related. However, he wondered if it would
be possible to do
module Foo;
module Bar {...}
and refer to the inner module as, say, 'Foo.Bar'. He also wondered about
scary things like anonymous modules.
Larry came up with answers, essentially you could get the semantics Luke
was after but not necessarily with the same syntax.
http://xrl.us/3qa
How to get environment variables
Andrew Shitov wanted to know how to get at environment variables from
the Perl 6 mini language that comes with Parrot. Judging by the error
report that he pasted on his second post, it looks like that's not
supported in the current Perl 6 implementation.
http://xrl.us/3qb
Announcements, Apologies, Acknowledgements
As I said earlier, it's been a busy week. It's fabulous to see things
like the PHP porting effort and Stéphane's work on Perl 6 regular
expressions getting underway.
I'm afraid that anyone who thought I'd manage two Monday summaries in a
row has been sadly disappointed. Sorry.
Despite that, if you found this summary valuable, please consider the
following ways of showing your appreciation:
* Take part. There's new, shiny projects to get involved with now,
maybe you have exactly the knowledge and skills they need.
http://dev.perl.org/perl6/ and http://www.parrotcode.org/ are
good starting points. Hopefully once the PHP porting effort gets
further down the road I'll be able to point you at a website for
that too.
* Take out your wallet and donate some good hard cash to the Perl
Foundation http://donate.perl-foundation.org/ to help support
Larry, Dan and Damian.
* Take the time to drop me a line at [EMAIL PROTECTED] letting me
know what you think. I was enormously pleased last week to get some
mail from someone at the Sanger Institute thanking me for the
summaries. Personally, I reckon the Sanger Institute deserves far
more thanks from all of us for keeping the genome free, but it's
always nice to be appreciated.
