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Perl 6 Design Minutes for 27 January 2010

chromatic on 2010-01-29T21:00:38

The Perl 6 design team met by phone on 27 January 2010. Larry, Allison, Patrick, and chromatic attended.

Larry:

  • tweaked definition of when a series operator is considered infinite
  • nailed down more list assignment semantics with respect to interators
  • clarified how ($a, $b, @a) = 1..* works
  • KeyWeight deletion criterion kept consistent with other KeyHash types
  • negative keyweights are allowed to fail at pick time
  • "mostly eager" now assumes unknown closure generators are probably infinite
  • random whackage on List, Seq, Parcel, Capture, Iterator, Nil etc.
  • List is now simply the iterator role, and doesn't do Positional
  • Seq takes over Positional duties for reified (or reifiable) value lists
  • think of Seq now as a constant Array (but also lazy like Array)
  • Iterable now means you can ask for an iterator, but doesn't do List
  • Array, Seq, etc do Iterable, but not List
  • only actual iterators do List
  • Nil is defined as a suitable sentinel for both list and slice iterators
  • continued to rethink that with pmichaud++ et al
  • we'll probably end up with an EMPTY special exception object to be the iterator sentinal
  • proposed an E operator to go with it to make testing for EMPTY across multiple iterators very fast
  • other than that, mostly just bug whacking, no major refactors
  • still thinking about doing real LTM for STD
  • did lazify Cursor's fnum->fate translations for shorter LTM candidates in preparation for smarter LTM
  • we don't need special objects for the items that get matches
  • we do need to think more about the hyper cases
  • how to do list processing using balanced trees of delegated sub refs
  • don't want to build in serial assumptions where we don't need them

Patrick:

  • made the Rakudo #25 release last week
  • it was much easier to make the release than explain what we were planning to do instead
  • also working on iterators and lists
  • NG branch is blocking on that
  • worked on the design in my head for three weeks
  • realized that we were doing iterators completely wrong the other night
  • Larry's making some useful changes to the spec in response
  • there are still some unclear spots in the spec
  • we need an implementation to figure those out
  • my biggest question is the relationship between List, Parcel, Itertor, and array
  • as of this morning, I think I have it
  • that code seems to be working and efficient
  • so far it's working well
  • continuing with that
  • wrote a very short range iterator prototype that colomon has used
  • also write a map iterator that works
  • coming up with examples for the zip operator was nice
  • good ideas for what we need to be able to do
  • objects that can iterate have a .iterator() method
  • to interpolate that into a list, .list() returns a flat Parcel for that iterator
  • Parcels know how to generate Iterators
  • those know how to handle Iterators of Iterators
  • I suspect that's how we do hyper iteration
  • change Parcels to understand that
  • adding pieces back into the ng branch
  • next I have to fix slurpy parameters
  • many of our builtins need that
  • need to figure out Jonathan's code to do that
  • after that, I'll do arrays
  • that should remove the blockers on the ng branch

Allison:

  • working on Pynie
  • Francois has helped greatly to update it for Plumage

c:

  • still working on the TT #389 fix
  • think I have the right design, just need time to implement it
  • working on a potential new time for #parrotsketch

Allison:

  • thinking about hackathons
  • would be nice to have a Rakudo hackathon at YAPC::NA

c:

  • Parrot will come up; didn't it come up about half the time last year?

Patrick:

  • it was all Parrot

Allison:

  • you'll have an influx of Rakudo interest two months after Rakudo Star

Patrick:

  • probably will have one before then
  • but can tell people "Go to YAPC; we'll show you how to help in person there"

YAPC::NA

colomon on 2010-01-31T13:08:21

Are there dates yet for YAPC::NA?

Unless there's some horrible scheduling conflict, I will be there for sure, as Columbus is an easy drive and I have family in the area. I would love to be involved with a Rakudo hackathon there.

Re:YAPC::NA

chromatic on 2010-02-01T07:03:44

YAPC::NA 2010 is June 21-23 in Columbus, Ohio.

Re:YAPC::NA

colomon on 2010-02-01T11:13:08

Thank you! I've penciled it in on my calendar, and will double check with my wife when she wakes up to make sure it's not the weekend of a wedding...