The Perl 6 Summary for the week ending 20030615
Welcome to the last Perl 6 Summary of my first year of summarizing. If I
were a better writer (or if I weren't listening with half an ear to
Damian telling YAPC about Perl 6 in case anything's changed) then this
summary might well be a summary of the last year in Perl 6. But I'm not,
so it won't. Instead, I'm going to try and keep it short (summaries
generally take me about 8 hours on an average day, and I really don't
want to lose 8 hours of YAPC thank you very much).
It's getting predictable I know, but we'll start with the internals list
again...
Class instantiation and creation
Dan continued slouching towards full OO and outlined the issues involved
with setting up classes and asked for people's opinions. People offered
them.
http://xrl.us/jou
Writing Language Debuggers
Clinton Pierce wanted to know how to go about writing language level
debuggers in Parrot. (This man is unstoppable I tell you.) He offered
some example code to show what he was trying to do. Benjamin Goldberg
had a style suggestion for the code, but nobody had much to say about
Clint's particular issue.
http://xrl.us/jov
Converting Parrot to continuation passing style
A lot of this week's effort was involved in getting support for the
Continuation passing style function calling into Parrot. Jonathan
Sillito posted a patch. This lead to a certain amount of confusion about
what needs to be stashed in the continuation and a certain amount of
bemusement about the implications of caller saves rather than callee
saves (in a nutshell, a calling context only has to save those registers
that *it* cares about; it doesn't have to worry about saving any other
registers, because its callers will already have saved them if they
cared.)
Dan ended up rewriting the calling conventions PDD to take into account
some of the confusion revealed.
I think the upshot of this is that the Parrot core now has everything we
need to support the documented continuation passing calling conventions.
But I could be wrong.
http://xrl.us/jow
http://xrl.us/jox
Segfaulting IMCC for fun and profit
Clint Pierce's BASIC implementation efforts continue to be one of the
most effective bug hunting (in code and/or docs) efforts the Parrot team
has. This time, Clint managed to segfault IMCC by trying to declare
nested ".subs" using the wrong sorts of names. Leo Tötsch explained how
to fix the problem. It seems that fixing IMCC to stop it segfaulting on
this issue is hard, since the segfault happens at runtime.
http://xrl.us/joy
Passing the time
Clint's BASIC can now place chess! Not very well, but we're in 'dogs
dancing' territory here. Bravo Clint! There was applause.
http://xrl.us/joz
Meanwhile in Damian's YAPC address...
New DISPATCH method
Last week Ziggy worried about multimethod dispatch not being good
enough. This week at YAPC, Damian announced DISPATCH, a scary magic
subroutine which allows you to define your own dispatch rules.
Essentially it gets called before the built in dispatch rules, beyond
that, I know nothing.
Sorry, no link for this.
Meanwhile in perl6-language
Ziggy's obsoleted thread
Last week I mentioned that Adam Turoff had worried a little about
multimethod dispatch, and wanted to know if it would be possible to
override the dispatch system in an easy way. This week, he outlines the
sorts of things he might want to do.
See above for the resolution. Details don't exist just yet, but we'll
get there.
http://xrl.us/jo2
Type Conversion Matrix, Pragmas (Take 4)
Michael Lazzaro posted the latest version of his Type Conversion Matrix
and asked for comments and hopefully definitive answers. There was a
small about of discussion...
http://xrl.us/jo3
Returning from a nested call
Whilst idly 'longing for the cleansing joy [of] Perl', Dave Storrs
wondered how/whether he could write a method that would return from its
caller. Answer: Yes, use "leave".
http://xrl.us/jo4
printf like formatting in interpolated strings
Edward Steiner wondered about having some way to to printf like
formatting of numbers in interpolated strings. Luke Palmer (who just
told me he's embarrassed about something I wrote about something he said
last week, but I'd forgotten it) came up with a cool looking suggestion
in response.
http://xrl.us/jo5
Acknowledgements, Announcements and Apologies
Well, that wraps up my first year of summary writing. Thanks to everyone
for reading, it's been fun.
I have one announcement to make: As of next week, there will be no
obligatory reference to Leon Brocard -- I'm getting bored of it, you all
must have been bored with it for months...
If you've appreciated this summary, please consider one or more of the
following options:
* Send money to the Perl Foundation at
http://donate.perl-foundation.org/ and help support the ongoing
development of Perl.
* Get involved in the Perl 6 process. The mailing lists are open to
all. http://dev.perl.org/perl6/ and http://www.parrotcode.org/
are good starting points with links to the appropriate mailing
lists.
* Send feedback, flames, money, photographic and writing commissions,
or a nice long US power cable to plug into my Mac power-brick to
[EMAIL PROTECTED]
--
Piers
