This week on Perl 6, week ending 2003-07-20

Welcome back to an interim Perl 6 Summary, falling between two conference weeks — OSCON and YAPC::Europe. For reasons involving insanity, a EuroStar ticket going begging, and undeserved generosity, I shall be bringing my conference haul up to 3 for the year. Yay me! Now if I can just finagle a talk into the schedule I will have spoken at all three too. I’ll certainly have heckled at all three.

The State of the Onion

Tim Howell wondered if Larry’s State of the Onion address to OSCON would be available anywhere. Robert “White Camel” Spier didn’t rest on his laurels, but posted a link to Larry’s slides and transcript. chromatic popped up with a different link which neatly combines slides and transcript. However, they both lack the funny balloon pony which I gave Larry just before the talk. Maybe there will be video later.

A Small Perl Task for the Interested

A few weeks back, Dan asked for volunteers to improve Parrot’s build system. Lars Balker Rasmussen stepped up to the plate and offered a simple wrapper. Josh Wilmes seems to be somewhat sceptical about the whole endeavour, pointing at libtool as an illustration of the size of the problem.


Parrot is in the process of getting an env PMC, for accessing environment variables. Dan and Leo’s discussion of the patch took in iterators and the wisdom of caching values. In the end, Dan prevailed and the environment PMC doesn’t cache values.

Dan on threading

“Yes, [there is some plan of how threading will work in Parrot]. (Though there’s some disagreement [as] to the solidity and sanity of the plan)“.

Dan went on to outline the plan.

Event handling

Event handling appears to be the topic of the week. The consensus seems to be that getting it right is hard. Lots of people offered constructive suggestions and problem cases. I sat on the sidelines and trusted them to get it Right (a strategy which seems to pay off remarkably often, thankfully).

Damien Neil was rather less sure of the wisdom of Parrot’s events and asynchronous IO model, arguing for a system based on threading. Dan was unconvinced. I don’t think Damien was convinced either.

IMCC sub names are not labels

Luke Palmer had some problems with using continuation passing style subroutines in IMCC. Leo initially pointed out that IMCC didn’t support CPS. Then he fixed it so that it did (sort of: the user still has to do a chunk of the work, but sometimes that’s a good thing).

In an example of synchronicity, Will Coleda had a similar problem. Leo’s fix helped him too, and he went off to continue hacking on Tcl. (It helps me too, as I have this cunning plot….)

More on targeting GCC

In last week’s summary I wondered what Tupshin Harper was talking about when he suggested emulating a “more traditional, stack-oriented processor”. This week, Tupshin wished that “people had the decency to tell me how insane [the idea] is”. Dan obliged, telling Tupshin that he was insane (but he did it with a smile).

The problem boils down to GCC’s assumptions about the “shape” of the stack. GCC assumes a conventional, contiguous area of stack memory filled with stack frames. Parrot assumes a garbage collected chain of continuations, which is about as far as you can get from GCC’s beliefs.

Parrot_sprintf not recognizing 7 in precision

mrnobo1024 posted a patch to fix a minor niggle with Parrot_sprintf. Leon Brocard applied it.

Problems with new object ops

Dan has started adding real classes and objects to Parrot. (Yay!)

Simon Glover found some bugs. (Not entirely unexpected.)

Simon also sent in a patch fixing the bugs. (Yay! Yay! and thrice Yay!)

The big core.ops split

Brent Dax has started work on splitting core.ops from being the second largest file in the Parrot distribution (108k) into a total of ten more narrowly defined .ops files. Benjamin Goldberg wondered if this would be a good time for tidying up the parrot directory structure. At the very least, he called for moving the source files into a src subdirectory.

Dan asked for a volunteer to rough out a move plan covering which files move where and what the new directory structure would look like, which would allow the jockeys to rearrange things in such a way that the various files remember their histories.


Josh Wilmes posted a monster patch to unify the various copyright notices attached to the files in the parrot distribution. Everything is now (correctly) copyrighted by the Perl Foundation.

Meanwhile, in perl6-language

Somebody needs to set an Exegesis among the pigeons. There’s all of 14 messages in there, almost discussing the semantics of aliasing an array slice. — Alias those slices

Parsers with Pre-processors

I didn’t quite understand what Dave Whipp was driving at when he talked about overloading the <ws> pattern as a way of doing preprocessing of Perl 6 patterns. I didn’t understand Luke Palmer’s answer either. Help.


Luke Palmer’s been toying with Objective-C (and why not, it’s a nice language) and would like Perl 6 to steal Objective-C’s protocols. Protocols are a little like Java’s interfaces, but nicer. I’m waiting for him to latch onto the idea of Categories which are Objective C’s way of adding methods to a class, at runtime.

Discussion of Luke’s proposal centered on a couple of his peripheral points. Nobody’s yet addressed his main point, but it looks like a decent idea to me.

Acknowledgements, Announcements, and Apologies

First of all, I plead insanity for my mistake of last week’s summary. PONIE does not stand for “Perl On New Internal Architecture”, it obviously stands for “Perl On New Internal Engine”. I’m very, very sorry and I’ll try not to do it again.

Editor’s note: the Ponie expansion was corrected in both summaries before publication. The summarizer has been whacked appropriately.

Secondly, an announcement, I’ve started one of those punditry/bloggy things. It’s at (Snappy URL eh?) and it’s called ‘Just A Summary’. I’m expecting it to concentrate on Perl and Perl 6 related issues, but at the time of this writing I’ve only got two ‘real’ articles up there so anything could happen.

As ever, if you’ve appreciated this summary, please consider one or more of the following options:

  • Send money to the Perl Foundation at and help support the ongoing development of Perl.
  • Get involved in the Perl 6 process. The mailing lists are open to all. and are good starting points with links to the appropriate mailing lists.
  • Send feedback, flames, money, requests for consultancy, photographic and writing commissions, or an Apple 23’ Cinema Display to (One of these days that begging request will work, and I’ll be flabbergasted).



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