Perl 6 Design Minutes for 06 January 2010

chromatic on 2010-01-23T00:12:46

The Perl 6 design team met by phone on 06 January 2010. Larry, Allison, Patrick, Will, and chromatic attended.

Larry:

  • in Spec Land, renamed p{} to qp{} to avoid using up another common single letter
  • bare say/print is now just a warning
  • Carl Mäsak dug up fossilized restriction on hash literals, which I removed
  • since the insides of blocks are now parsed as statements, there is no longer an inconsistency in line-ending curlies
  • refined the picking vs grabbing semantics with respect to immutable vs mutable bags and such
  • to avoid legacy confusion, renamed break/continue to succeed/proceed
  • clarified that an implicit succeed returns the value of the whole when block
  • it is not somehow magically inserted around the last statement
  • renamed true to so to avoid confusion of the predicate with the True enum value
  • at the suggestion of moritz++, split Any up into Any and Cool types
  • Cool stands for Convenient OO Loopbacks, or any other acronym you'd like
  • the built-in types derived from Cool are the ones that do Perlish dwimmy coercions
  • user types still derive from Any by default, so aren't born with gazillions of methods
  • conjecturally, also keep "last-resort" multis in Cool package
  • responded non-explosively to a potentially explosive rant/twitter
  • clarified various things in response
  • it is not necessary that all implementations be equally good at everything
  • there will be a minimal Perl 5ish grammar alongside STD that any VM can support as a well-behaved subset
  • it is also acceptable to support bug-for-bug compatibility with Perl 5
  • the language designer is neither omniscient nor omnipotent
  • the design process is therefore convergent on the part of all parties involved
  • the rate of convergence is an emergent property, and is to be forced
  • convergence is deemed to be positive as long as anyone is still working on Perl 6
  • the solidification of the spec is also part of the convergence, and depends on proven implementation
  • unproven parts of the spec are to be considered implicitly conjectural
  • as implementations converge on specs, we can throw out or delay parts of the spec that as yet unproven
  • everyone is allowed to panic once.
  • on to implementation, found fencepost precedence error inside list prefix
  • moved the default initparse method from STD into Curso so other grammars don't have to define it
  • added quote modifier :p (aka :path) so we can form the qp{} path literal
  • installed better warnings about bare say/print
  • generalized the say/print warning to anything a p5er might try that might be in p6 without the defaulting
  • STD and CORE now support recent renamings to so, succeed, and proceed
  • no longer reports "Bogus statement" when "Missing term" is more accurate
  • now catches /\b/ and advises to use an appropriate p6 word boundary assertion instead
  • emits better message when an intended reduce is interpreted as composer
  • detects most attempts to use postfix after whitespace, and suggests omitting whitespace
  • now parses tick-less embedded comment syntax as line-end comment (but still warns for now)

Patrick:

  • took the last couple of weeks off
  • keeping up with things, but not much writing code
  • read the S01 changes with great interest
  • glad to see them
  • answered some PGE questions for Carl

Larry:

  • we've talked about them all along
  • they weren't written down in an obvious place

Will:

  • working on Parrot
  • trying to move as much out of the configure process into a Makefile as possible
  • intended to improve the build
  • attempting to remove recursive makes
  • avoid unnecessary rebuilds
  • improve dependency tracking in the build
  • probably ready after 2.0

Patrick:

  • I'm impressed
  • thanks for taking that on; we needed it

Allison:

  • working on deprecation notices
  • we've talked about a lot of things over the past six months
  • not sure they're all in the file appropriately

c:

  • working on bugfixes
  • also working on deprecations

Patrick:

  • I intend to merge the ng branch before the January release
  • some people are antsy, but I have a lot of confidence
  • we'll probably pass about 70% of the test suite
  • it looks like a regression, but we have different features added now
  • lazy lists work, for example
  • lots of things fudged in the previous version work now


Hooray for P6, and thank you for the summaries.

thickas on 2010-01-25T07:33:46

Reading the P6 summaries on use.perl is a real highlight of both my week and the Internet.

Thank you very much for publishing them.

Recently I have been reading the Bruce Payette book "Power Shell in action". PS like P6 has taken a radical approach to succeeding in its mission. Payette's book acknowledges the inspiration of P5 (at one point P5 was the root language) and also that the P6 solution to vardic parameter binding is probably canonical, and that chosen by PS.

PS may be a less successfull solution than P6 since it has made some breathtaking decisions. For example, the built in -match (Huffman encoding is nothing to PS) operator has context sensitive behaviour (scalar vs array/list), but fails to provide a global match function. One has to call a .Net method on the regex class to do that ....

That said, if you are MS, radical solutions are not a problem (and you have nothing to care about in the way of backward compatibility/legacy code).

May P6 be genuinely innovative but helpful at the same time, especially to very ordinary men such as YT.