Advogato: Blog for chromatic

Perl 6 Design Minutes for 13 May 2009

The Perl 6 design team met by phone on 13 May 2009. Larry, Allison, Patrick, Jerry, Will, Nicholas, and chromatic attended.

Larry:

continuing to think about how braided languages work
implementing the notion in the STD parser
the notion of how you switch between these languages
now called slangs
thinking about how macros work in embedded lexical scopes
if you define a role which contains a trait auxiliary definition
label it is export
how does it export?
to which lexical scope?
when you do the role or what?
no defined way of exporting to outer
that's a problem in some tests
with augment slang, we have a way of embedding grammar modifications inline
when do ordinary macros embedded in subscopes desugar to that sort of thing?
%*LANG now holds the whole language braid
the $*PARSER variable is just the MAIN element of that
I backed off some of the errors in the STD parser to just warnings
don't really handle module and role long names yet
you get bogus "can't augment" warnings now
it thinks something isn't there that should be there and vice versa
fixed a test where STD needs to parse =for; now it does
added the slang declarator so that we could augment them
a twigil indicates a current slang subset of the current braid
fixed a bug to recognize the invocant marker after an unspace
that was a longest-token match problem
the message I added about a missing block gobbled by a function is now two separate messages
one talks about the function which needs parens
the other talks about the missing block
they point to two different areas as a matter of clarity
I'm really enjoying adding clever error messages

Patrick:

Rakudo now passes 11,200+ tests
up by 70 tests since yesterday
a couple of hundred in the past week
mostly doing little bug fixes and refactors
typically, I'll start to add a feature and find some code which doesn't look right
then I add the feature
slurpy arrays and hashes weren't added properly to subs
always added automatically regardless of the type of Block
I cleaned that up
also cleaned up lots of parameter handling in the code
that made actions.pm 100 lines shorter, and I removed three duplicate subroutines

Patrick:

every time we do that it helps
found a bug dealing with Unicode characters in grammars
prevented us from properly parsing French quotes as an angle delimiter
working on adding operator parsing to Rakudo today
define your own custom operators
refer to them using canonical names
expect to have that done today
they won't be lexically scoped
I'll work on fixing that, when we get more to lexical scopes and language braids
continuing to consider protoregexes and LTM in PGE
probably will implement contextual variables in NQP and Rakudo

Allison:

Jerry:

Larry:

Patrick:

Will:

Patrick:

Nicholas:

Rafael has merged his smart-match branch back into blead
he tried to make smart-matches match ranges
it won't work for various reasons
precedence is the wrong way around for one
$foo ~~ [ 1, 2, [ 3<nobr> <wbr></nobr>.. 5 ] ] won't work either
Perl 5 ranges aren't lazy
smart-match can't interrogate Range objects lazily
that's why we can't emulate everything from Perl 6
we don't have the low-level infrastructure to do it all
even if we had that infrastructure, there are parsing issues
I don't see that coming in a hurry
if someone implements lazy ranges, maybe someone can add them to smart-match
giving the enjoyment people derive from implementing such things, I'll be surprised if anyone does that

Nicholas:

Patrick: