The Perl 6 design team met by phone on 23 April 2008. Larry, Allison, Patrick, Jerry, Will, Jesse, Nicholas, and chromatic attended.
Jerry:
- we're in a period where everyone's trying to break Parrot
- they're adding new features and accidentally breaking thing
- but they're fixing it
- it's a good part of the cycle
- people fix it
- we don't have a build farm, so we can't test everywhere before
committing to trunk
Patrick:
- I thought that was the point of the release cycle
Jerry:
- some people have suggested that we always keep trunk building and passing tests
- but we don't have the means to do that
- especially when we're playing with config
- moving on, the big news is that TPF has six slots in Google's Summer of Code
- one of them is fleshing out the Perl 6 test suite
- we've needed someone to spearhead that
- having a funded new contributor is wonderful
- two Parrot-related projects
- one is generating NCI stubs
- Kevin Tew, a long-time contributor
- the other is the incremental GC specified in the PDD
- that's Andrew Whitworth
- there's also an ASF project for integrating the GC from Apache Harmony into Parrot
- they've wanted to release it as a standalone library
- Parrot's the first test of a standalone system
Nicholas:
- nice that it doesn't count against TPF's slot list
Jesse:
- and it's nice visibility for Parrot from another group
Jerry:
- I finally have six weeks of no plans to travel
- should be able to devote more time to Parrot and Rakudo
- looking forward to that
Larry:
- getting some hacking in on my two pet bugaboos, the longest token matcher and match object generator
- I refactored the matcher
- it still uses TGE
- instead of lumping all of the expect term possible tokens (that is, all of them) into one bucket it separates them into buckets based on their first letter
- it's a one-level tree
- we can build a much smaller DFA for the regexes that start with that letter
- it caches that, of course
- can get an instant reject if the next token can't possibly start with that letter
- also flattened out all of the rules such that the list of tokens is easy to read
- if the first probe with the DFA engine fails, I can take that small set of tokens that start with the same letter, run all of those rules, and sort from longest to shortest
- preserves the token matching order without building huge DFA structures
- as a backoff strategy, that will scale pretty well
- refactored the parameter passing on the matcher side (STD 5)
- instead of passing an initial array of random things, I have parameters
- constructs match objects more correctly
- in the sense that it gets all the information it's supposed to have
- also has some attachments where it shouldn't have
- I'm cleaning that up
- that should scale pretty well
Jerry:
- is there a drop in memory usage?
Larry:
- I haven't measured
- I'm sure that not feeding 800 regexes to TRE at once will make it allocate 17 megabytes on the stack
- it might still be allocating too much for some of the larger things
- I'm still aiming for correct, as opposed to fast
- just trying to bear fast in mind
- the longest token matcher now returns a linked list of states
- not a string
- should be a lot faster; easier to cache
- functionally it's the same as before
- one of those things you don't even have to measure to know it'll be faster
- trying to avoid the bugaboo of premature optimization by doing what I know will be efficient to begin with
- all the while trying to make the thing work
- it has a good chance of being pretty speedy
- my talk in Tokyo will be about all of the places where the current grammar allows extensibility
- it'd be nice to be able to demonstrate some of that
Allison:
- getting work done again
- launched the Strings PDD
- list of tasks for concurrency that I'm breaking down into smaller pieces
- may post what I have now, and leave other people to break them down
Patrick:
- are they parallelizable? :)
Allison:
- many of them are
- there are some bigger things, like switching the exception system over to the event handler
- otherwise, just life stuff
Patrick:
- had paying work come up this past week, so not a lot of actual coding
- need to type the milestones document
- it's all in my head
- managed to remove a lot of unused code thanks to chromatic's post about possible optimizations
- mostly just cleanup
- but helped me figure out things which will feed into my redesign of PGE for longest token matching
- should be able to return to direct Rakduo hacking later this week
Will:
- various Parrot cleanups
- TPF quarterly grant proposals are due at the end of the month
- haven't seen anything come in yet
Allison:
- they're queued in an RT queue
- I don't know if grant members have access to that queue
Will:
- we do
- please, get your proposal in now, sooner than later
- that goes for you on the call as well as people reading the minutes
c:
- mostly spent the past week optimizing Parrot and Rakudo
- looks like it's the building speed is twice as fast as when I started
- runtime is faster too, but the optimization is compilation time
- found some infelicities that need more design thought
- but I'm happy to put these improvements in now and take them out later when the design improves around them
- hope to start adding new features again soon
Patrick:
- most of the test execution time is in compilation
- how useful would it be to compile Rakudo to standalone PIR?
c:
- I'd find it useful
- but I'd find about ten things useful with all I work on
- so not a blocker at the moment
Jesse:
- how far will that get you toward native executables?
Patrick:
- the existing trick for building perl6 would work
- but it's not the same
c:
- if it takes an hour or two, it would help me with debugging and profiling
- if it takes more time, it's not that important
Patrick:
- we have to figure out runtime deployment issues for the Perl 6 runtime library
Will:
- we could add the requirement to run from languages/perl6/ right now
c:
- that's fine by me for now
Patrick:
- that's an afternoon job, not too bad
- what do we need to do to get the Perl 6 and Parrot pages up to date?
Will:
Nicholas:
- why is C99 useful to Parrot and the compiler tools?
c:
- front-end parsing for C header files to build NCI declarations automatically
- the backend is pretty easy, that's thunk generation
- the front-end keeps people from having to write boilerplate code by hand
- generate the front-end once, where you have the headers, and then you can run the generated code anywhere even if you don't have the headers
Jesse:
- how does that compare to Python's ctypes?
c:
- as I understand it, they have the nice backend stuff
- not so sure about the front-end
- my P5NCI is nicer, if incomplete
- just haven't had time to work on it...
Jesse:
- if you put in for a TPF grant, that would be very useful
c:
- get me a clone first, and you have a deal
Jerry:
- Allison, we talked about implementing
return
- that requires tying in exceptions to the concurrency scheduler?
Allison:
- yes
- just not implemented yet
- when we did exceptions, we didn't have concurrency
- so it's on the top of my list to tie them together
Will:
- Tcl's already using exceptions to handle
return, break, and continue
Allison:
- right now, you can't have an exception handler which is a full subroutine
Patrick:
- I'm not sure we need one for that feature
- every subroutine block decorated as such in PAST puts an exception handler in the block
- if any nested block throws a
return type exception, it grabs the arguments, does what it has to, and then does a Parrot return
Allison:
- if that's what you need, go ahead and do it
- I thought there are some features you didn't have yet
Patrick:
- I thought there might be some opcodes I needed, like
handled
- but we can do something now
- might not be completely optimal
- but it's just packaging things up now
- I have something I think will work
- it's not trivial, but I'm 80% confident
- just a matter of sitting down and doing it
Allison:
- the concurrency stuff will be there before the next release
- might not want to roll it in before the release
- but it'll be there soon
Patrick:
- I want to get
return in for the April 15 milestone we're behind on
Jerry:
- have you put in tickets for the breakdown of specific tasks?
Allison:
- I've never done tickets for that
- just sent mail to the list of the tasks
- handed them out to people as they volunteered
c:
- can you put them on a wiki page?
- some of the other committers wanted that
Allison:
