The Perl 6 summary for the week ending 20031130
Welcome back to the weekly Perl 6 Summary, which I'm hoping to keep on a
weekly cycle for the foreseeable future.
It's been a relatively low volume week this week, I'm assuming that
Thanksgiving had something to do with it (I hope those of you who
celebrate it had a jolly good extended weekend), and for the first time
in ages perl6-language saw almost as much traffic as perl6-internals.
We're still going to start with perl6-internals though.
Some PIR "How do I?" questions
Last week Dan put up a list of questions about IMCC, intending it as a
bit of grit. This week Melvin Smith added a couple of layers of nacre by
checking in an initial IMCC FAQ (you'll find it at imcc/docs/imcfaq.pod
in your parrot directory if you're following with CVS). After an initial
flurry of work on adding to the FAQ, the discussion seems to have
drifted off into discussions of bike shed pigmentation. Yes, the FAQ may
need to be split eventually, but splitting an FAQ into sub documents is
trivial compared to actually answering the questions. Ahem. Editorial
ends.
http://groups.google.com/[EMAIL PROTECTED]
http://www.parrotcode.org/faq/imcc -- The FAQ
PIO_eof
Vladimir Lipsky had a few questions about how the Parrot IO subsystem
(PIO) handles error conditions. This sparked a discussion of whether the
various PIO functions should make some assertions up front about their
arguments. Consensus said "yes", they help with debugging, and the
performance 'hit' is minuscule.
http://groups.google.com/[EMAIL PROTECTED]
Freezing and Thawing
Discussion of the details of object serialization continued this week.
Judging by the amount of clarification traffic that's been going on in
this thread (and others), I find myself wondering if the time has come
for some generous benefactor to sponsor the principals to get together
in a conference room with copious whiteboard acreage. Sponsors welcome.
http://groups.google.com/[EMAIL PROTECTED]
Segfault warning boxes
Consider a system of test machines, all of them happily running in
unattended mode, constantly checking out the latest version of parrot,
compiling everything, running the tests and reporting the results to
some central webserver that displays a status report for all to see.
It's not just a good idea, it's the Parrot tinderbox.
Now, consider an operating system that takes it upon itself to throw up
a modal dialog box when a program segfaults.
The two don't sit well together do they? Which is why Dan has committed
a patch to disable the "Your program has crashed, want to send a report
to Microsoft?" box that pops up on Win32 when Parrot segfaults. Still,
at least it can be disabled.
Dan asked for opinions on whether the (non tinderbox) default should be
to put up a dialog box or not. And it appears that, if you disable the
dialog box, there's no other notification (apart from the failed test,
obviously) that there was a segfault. I am sure I'm not alone in
boggling at this, but it looks like the default will be to display the
dialog.
http://groups.google.com/[EMAIL PROTECTED]
Perl 6 updated
Allison Randal sent in a patch to update the Perl 6 compiler to use the
right operators ("^+" becomes ">>+<<", "~~" (meant xor)
becomes "^^", making way for "=~" to become "~~"). She's still working
on other tweaks to get the semantics of what's already been implemented
right, and claims to be sufficiently annoyed by the failing regex tests
that she might have to go and make them work to remove the annoyance.
Which would be good. (I'm afraid that the tantalizing code I mentioned
last week has actually been there for ages, as I feared it had). That
capital fellow, chromatic applied the patch.
http://groups.google.com/[EMAIL PROTECTED]
String formatting and transformation
Dan got around to specifying some details about string formatting and
transformation. Essentially there will be various case changing
transformations and a couple of different formatting approaches, one
"sprintf" like and another more like traditional COBOL style formatting.
Dan's not sure yet whether these formatters will get ops or simply be
implemented in the standard library.
http://groups.google.com/[EMAIL PROTECTED]
AUTOLOAD anyone?
Someone calling itself ibotty wondered if there would be a default PMC
method that gets automagically called whenever a method call isn't
found. To which the answer is "Yes, when it's done".
http://groups.google.com/[EMAIL PROTECTED]
erl.org
Determining PMC memory addresses
Cory Spencer wanted to know if there was a PASM way of finding whether
two PMCs share the same memory address. "Not yet", said Leo Tötsch, "but
there are entries in the vtable to do it". This sparked a discussion of
the meaning of 'equal'. It was suggested that Parrot use Lisp's triple
equality test operators (one tests if two things are the same thing, the
second if two things have the same value, and the third tests that they
have the same structure). Jos Visser argued (convincingly I thought)
that having three operators with the same semantics might be a Good
Thing, but using Lisp's names ("eq", "eql" and "equal") for them would
definitely be a Bad Thing.
http://groups.google.com/[EMAIL PROTECTED]
Meanwhile, on perl6-language
'Core' language philosophy
Branching off from a thread about using "catch" as a statement modifier
*á la* "if", "unless" etc., Michael Lazzaro waxed philosophical about
the distinction between core and library. He wondered if putting
syntactic sugar into CP6AN and then having almost everyone install it
anyway wasn't a false economy. He went on to defend the idea of the
"catch" modifier.
Larry didn't agree. He suggested that a better way would be to look at
some kind of pragma which would make "err" (the low priority form of
"//", aka 'defined or') put an implicit "try" around its left hand
argument. Michael still wasn't keen, but he wants to use "undef" to
stand for a SQLesque NULL.
http://groups.google.com/[EMAIL PROTECTED]
The C Comma
Luke Palmer doesn't like the C Comma -- the one that lets you write:
while $n++, $foo > $bar {...}
He does like the semantics though, so he proposed renaming the C comma
and calling it "then". People liked the idea of changing the name
because, if nothing else, it would mean one could write "@foo = 1,2,3;"
and get a list with three elements rather than a one element list
containing the number 3. However, they weren't necessarily keen on
"then" as the new name. Damian wondered if we shouldn't just insist on
while do { $n++; $foo > $bar } {...}
And then people started coming up various synonyms for 'and' in Latin
like *ac*, *cum* et cetera. Larry hasn't ruled on any of the options
yet.
http://groups.google.com/[EMAIL PROTECTED]
Properties
Luke Palmer once again demonstrated his mastery of the telling question
by asking a series of questions about runtime properties. Larry's
answers, both to the immediate question and in the thread that followed
make for fascinating reading and leave us all waiting with bated breath
for Apocalypse 12 on Objects.
I'm afraid I'm going to punt on attempting to summarize the thread
though; Larry's always hard to summarize when he's introducing anything
new. You really should (at least) read his initial sketch though -- role
based object orientation looks (to this reader at least) like a
brilliant idea.
http://groups.google.com/[EMAIL PROTECTED]
http://groups.google.com/[EMAIL PROTECTED]
-- Larry outlines his current thinking
Acknowledgements, Apologies, Announcements
I've still not got 'round to getting the link shortening in place I'm
afraid. For some reason the appropriate modules don't seem to want to
install on my G5. Maybe next week.
Leon Brocard has taken on the role of Pumpking for Perl 5.004 and will
not be appearing in these summaries for the duration of his reign out of
respect. After all, being a pumpking requires a kind of dignity that
would be incompatible with being a running joke.
If you find these summaries useful or enjoyable, please consider
contributing time and/or money to the Perl Foundation to help support
the Perl 6 effort. You might also like to send me feedback at
[EMAIL PROTECTED], or drop by my website.
http://donate.perl-foundation.org/ -- The Perl Foundation
http://dev.perl.org/perl6/ -- Perl 6 Development site
http://www.bofh.org.uk:8080/ -- My website, "Just a Summary"
