Perl 6 Summary for 2004-11-08 through 2004-11-15
All~
Welcome to yet another Monday summary. This would have been a Sunday
summary, but Avernum (from Spiderweb Software) forcibly prevented it. As
usual, we will start out with Perl 6 Language.
Perl 6 Language
modules and exports
Aaron Sherman wanted to know some specifics about exporting things from
modules. In particular, he did not want to have to retype a whole bunch
of things. Larry gave an answer indicating that some of what Aaron wants
should occur, but some things are difficult for good reason.
<http://xrl.us/dy47>
AUTOCLASS(DEF)? hooks
Rod Adams wanted to know if he could get AUTOCLASS and AUTOCLASSDEF
hooks. Larry told him that he probably could. Rod also wanted module
name aliasing. Larry told him that he could. Rod wanted to have module
names with arbitrary strings. Larry told him that he could. Rod wanted
to be able to load multiple version of the same module. Larry told him
that he could. The summarizer wanted each question of different focus to
be in a different message. Hopefully, Larry will tell him that they
should...
<http://xrl.us/dy48>
matching the nth occurrences
Sudarshan Gaikaiwari wanted to know how to match the "2nd last" last
occurrence in Perl6 rules. I think the message might have been posted
directly to google groups, as I did not get it in my email and nobody
replied. The example given matches the 2nd occurrence. As I am not sure
what is meant by "2nd last", I will answer the question I do know.
"m:2nd/foo/" will match the second occurrence of foo. The nth occurrence
can be accessed similarly.
<http://xrl.us/dy49>
Perl6 Compilers
Once again it is a race to see whether someone posts a comment to or
google picks up Perl6 Compilers first.
Parrot
Welcome to the week of the continuation. If continuations make your head
hurt overly, I advise taking a few Advil's before continuing. If
continuations are the way you naturally think, I would advise you to
stop playing with LISP compilers.
string pinning
Bernhard Schmalhofer wanted to pass the same C-string into to different
external functions so that the first could do things to it that the
second required. However, the solution that he found kept eating his
string after the first invocation. Dan and Leo came to the conclusion
that the 'd' parameter for NCI was the correct thing to use in this
situation.
<http://xrl.us/dy5a>
GC invocation
Last week Leo posted a radical idea about GC invocation, and I decided
not to invoke Warnock's Dilemma too soon. This week, I invoke it.
<http://xrl.us/dy5b>
perl vs /usr/bin/perl
Gerd Pokorra requested that "#! perl" be changed to "#! /usr/bin/perl".
Although Warnock applied, I think that this will likely not happen as
perl in not necessarily installed in user bin and people might want to
change which perl is invoked by changing there path.
<http://xrl.us/dy5c>
Command line support for various compilers
Will Coleda added a TODO item so that parrot can take various compiler
arguments on the command line. What are you waiting for?
<http://xrl.us/dy5d>
Register Stomping
Matt Diephouse was having troubles with his newly updated forth
compiler. The verdict seems to be that he has uncovered a bug. To quote
Matt, "*sigh*".
<http://xrl.us/dy5e>
Calling Continuations, Basic Blocks, and Register Allocation
Either Leo or Jeff Clites (I don't recall who) started what is probably
the largest thread for this week, whose focus is register allocation and
continuation troubles. Apparently the presence of continuations can
unduly extend the life time of registers (as can try-catch things, but
they seem less important. The suggested sollutions all have some
shortcomings, although it appears that only using lexicals is winning.
<http://xrl.us/dy5f>
<http://xrl.us/dy5g>
basic compilation example
Jeff Clites wondered how something like (a + b) would compile. The
answer is that intermediate PMC should be initialized to Undef which
will morph as appropriate.
<http://xrl.us/dy5h>
eval changes
Leo updated the implementation of eval to make it even cooler or
possibly just clean it up and fix some bugs.... I forget.
<http://xrl.us/dy5i>
Basic operations for MMD
Dan asked for volunteers to speck out the basic vtable and MMD functions
for CLS (common language something-or-other). Sam Ruby said he would be
willing to take a stabe at it in a few weeks. One week has gone by, and
Sam grows ever closer to stabbing things.
<http://xrl.us/dy5j>
no limit on imcc identifier length
Will Coleda noted that there was no limit on the length of imcc
identifiers. Here come the eval buffer overflow attacks...
<http://xrl.us/dy5k>
Duplicate local labels break PASM
Will noticed that duplicate local labels cause IMCC to output broken
PASM. I could be mistaken, but I though that IMCC -> PASM has been
broken for a while...
<http://xrl.us/dy5m>
Parrot API
Leo wondered if the parrot_api.pl could be less strict about what it
thought was public and what was not. Jarkko Hietaniemi responded that
that was not his call to make, and silence reigned supreme.
<http://xrl.us/dy5n>
Empty Sub troubles
Will Colleda posted a bug for empty subs in IMCC. Stéphane Payrard
provided a fix. Leo applied it.
<http://xrl.us/dy5o>
Languages with Object Support?
Jeff Horwitz wondered if there were any languages with object support
that he could bend to the evil ends of mod_parrot. While no one
answered, I think Parakeet might be such a language...
<http://xrl.us/dy5p>
WinXP problems
Christian Lott has been having troubles with WinXP. In particular
problems with ops2vim.pl. Read on for the blow by blow.
<http://xrl.us/dy5q>
Strings + Woking Correctly = Pain
In his noble efforts to make Parrot respect foreign languages and
cultures, while not necessitating ICU. Dan has been doing massive
reworkings of strings. He reports... progress... He also posed a
question for all to ponder: "How global should the defaults be?"
<http://xrl.us/dy5r>
<http://xrl.us/dy5s>
<http://xrl.us/dy5t>
<http://xrl.us/dy5u>
runtime/parrot/library/config.pbc
Nicholas Clark wondered what would generate this file. Leo answered.
Nicholas tracked his problem down to a quirk in FreeBSD make and fixed
it.
<http://xrl.us/dy5v>
#line directives from PMC files
Nicholas Clark announced his triumph over #line directives in pmc2c2.pl.
People were impressed, but promptly asked how to turn it off. Kids these
days don't appreciate what they got ;-)
<http://xrl.us/dy5w>
Tail Calls
Jeff Clites asked about tails calls in the pressence of continuations.
After much debate, the concensus seems to be that they don't effect
eachother much at all. In fact continuations make tail calls easier.
However, the topic of whether these were an optiization that IMCC should
detect or they should be explicitly generated by the compiler also came
up. I think the final decision was compiler generated, although I doubt
I would be alone in not minding if IMCC had a flag to allow it to add
them as it saw fit...
<http://xrl.us/dy5x>
Character Classes
Patrick R. Michaud wanted to know if Parrot had character class support
(i.e. checking membership). Leo responded that it would after Dan's
aforementioned string stuff.
<http://xrl.us/dy5y>
POSTCOMP vs LOAD
Leo asked what the differences between POSTCOMP and LOAD are. Dan
provided the answer: POSTCOMP is run only when (and as soon as) the sub
is compiled. LOAD is run when the sub is loaded. This need not be the
same time if the source is used to generate bytecode which is later
executed.
<http://xrl.us/dy5z>
Register allocation/spilling/volatitlity
Jeff Clites suggested using variable size register frames with explicit
volatile and non-volatile sections. Leo responded that this would cause
serious code bloat, and pointed him to his and Miroslav Silovic's
"watermark" scheme. Others voiced support for this as well as removing
the implicit operands. Dan said no.
<http://xrl.us/dy52>
AIX JIT gnomes
Adam Thomason observed that the AIX JIT problems have gone away and
thanked the gnomes responsible. Remember, the proper sacrifice for
little people like gnomes are mini-Milanos or other reduced size cookies
(nothing from Keebler as the gnomes and elves have long unresolved
issues).
<http://xrl.us/dy53>
Register Allocation for Fun and Profit
Bill Coffman's register allocator (or should I say his implementation of
the Matula/Chaitin/Briggs algorithm) grows ever closer to being commited
(although my initial prediction of two weeks ago was clearly wrong). In
fact, his algorithm is so good that it even turned up bugs from other
peices of the code. Dan started a test run on his evil code, so we
should have truly stressed performance numbers within the next several
fortnights.
<http://xrl.us/dy54>
<http://xrl.us/dy55>
imcc segfault on bad if
Gopal V found a way to make imcc segfault. I think it is still waiting
for a fix...
<http://xrl.us/dy56>
no perldoc == BIG FAT WARNING
James deBoer submitted a patch to fail if config did not find perldoc
last week. This week the request has gone out to modify it to warn in a
big and preferably fat way. No answer yet.
<http://xrl.us/dy57>
RT clean up
Will Coleda, whose dilligent minding of the RT queue is much
appreciated, closed a few tickets which no longer applies.
<http://xrl.us/dy58>
<http://xrl.us/dy59>
BASIC compiler
Will "Dr. Frankenstein" Coleda has attempted to resurrect the basic
compiler with some major surgery. He is making progress. Joshua Gatcomb
put out a request for a new maintainer.
<http://xrl.us/dy6a>
<http://xrl.us/dy6b>
Config provides slightly more info
Luke Palmer provided a patch for making Configure.pl slightly more
informative. Brent 'Dax' Royal-Gordon applied it.
<http://xrl.us/dy6c>
find-method inheritence
Sam Ruby asked for comment before committing a patch to allow calling of
attributes as methods and to allow inheritence of attributes. When no
one commented, he committed.
<http://xrl.us/dy6d>
Threads, Events, Win32
Gabe Schaffer pointed out some issues with threads and events from a
Win32 perspective. Leo pointed out that this has not yet been fully
implemented/abstracted/documented and observed that Gabe would be a
welcome volunteer.
<http://xrl.us/dy6e>
core dump on japh16
Bernhard Schmalhofer noticed that japh16 coredumps. He also submitted a
simplistic fix.
<http://xrl.us/dy6f>
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