Re: hotplug regexes, other misc regex questions
Josh Jore wrote:
Would it be correct for this to print 0? Would it be correct for this
to print 2?
my $n = 0;
aargh =~ /a* { $n++ } aargh/;
print $n;
Yes. ;-)
Wouldn't that print 2 if $n is lexical
Err. It *is* lexical in this example.
and 0 if it's localized?
No. Without the Cmy it would still print either 0 or 2, depending
on the implementation/optimization.
Or are lexicals localized now?
They can be. But this example C$n isn't.
(Just because it's used in a nested closure doesn't mean it's
localized within the pattern).
What possible outputs are legal for this:
aaa =~ /( a { print 1 } | a { print 2 })* { print \n } x/
I take it that what I've learned from _Mastering_Regular_Expressions_
doesn't quite apply here? From that interpretation I'd think it'd print
111\n since the second part of the alternation wouldn't be tried.
No. It would fail to match the final Cx in the pattern and start
backtracking.
Damian
RE: Hyperoperators and dimensional extension
Dan Sugalski:
# Sort of, yes.
#
# Basically the behaviour of hyper-operated operators is delegated via
^
Spending time in England lately? ;^)
# multimethod dispatch to the hyper-operator functions. By default the
Well, yeah. But that doesn't really answer my question. :^) What's
the *language-level* behavior?
--Brent Dax [EMAIL PROTECTED]
@roles=map {Parrot $_} qw(embedding regexen Configure)
Wire telegraph is a kind of a very, very long cat. You pull his tail in
New York and his head is meowing in Los Angeles. And radio operates
exactly the same way. The only difference is that there is no cat.
--Albert Einstein (explaining radio)
RE: Hyperoperators and dimensional extension
At 8:27 AM -0700 9/19/02, Brent Dax wrote: Dan Sugalski: # Sort of, yes. # # Basically the behaviour of hyper-operated operators is delegated via ^ Spending time in England lately? ;^) Why, yes, actually. :-P But I've been using Pompous English Spelling for years. # multimethod dispatch to the hyper-operator functions. By default the Well, yeah. But that doesn't really answer my question. :^) What's the *language-level* behavior? Well, it does, though. Saying it's delegated to the variables and they have a default behavior's different than saying this is the behaviour. -- Dan --it's like this--- Dan Sugalski even samurai [EMAIL PROTECTED] have teddy bears and even teddy bears get drunk
Re: Perl 6 Summary for week ending 2002-09-15
On Wednesday, Sep 18, 2002, at 17:42 Europe/Berlin, Piers Cawley wrote: IMCC / Mac OS X problem Leon Brocard (yay! Still batting 100% on this one...) has been having problems building IMCC under Mac OS X. The individual .c files all compile, but bad things happen at link time. Leo, Kevin Falcone, and Andy Dougherty all pitched in and, after a flurry of patches, IMCC is now building and working correctly under Mac OS X. http://makeashorterlink.com/?R591215D1 Have those patches committed, yet? I tried last night (instead of sleeping...;-)) but failed utterly. Regards, Kay
Re: hotplug regexes, other misc regex questions
On Wed, 18 Sep 2002, Luke Palmer wrote:
On Wed, 18 Sep 2002, Josh Jore wrote:
On Wed, 18 Sep 2002, Damian Conway wrote:
What possible outputs are legal for this:
aaa =~ /( a { print 1 } | a { print 2 })* { print \n } x/
I take it that what I've learned from _Mastering_Regular_Expressions_
doesn't quite apply here? From that interpretation I'd think it'd print
111\n since the second part of the alternation wouldn't be tried.
The first time through, yes. But then it tries to match the x, and says
oops, that's not what I have and backtracks. That tries the second of
the alternation, which doesn't work either. So it backtracks so the * is
only getting two of the first one, et cetera...
Or are you talking about something else from Mastering Regular
Expressions? Like some kind of optimization that happens?
I missed the trailing 'x/' since my perl5 eyes read that as '/x'. My bad.
Joshua b. Jore -{ weird geeky madness }- http://www.greentechnologist.org
Re: Perl 6 Summary for week ending 2002-09-15
Kay Röpke wrote: On Wednesday, Sep 18, 2002, at 17:42 Europe/Berlin, Piers Cawley wrote: IMCC / Mac OS X problem Have those patches committed, yet? I tried last night (instead of sleeping...;-)) but failed utterly. No, sorry. I'm still waiting for my imcc 0.0.9 patch to be checked in, where these fixes are included. If urgent you could follow the mentioned thread. There were all the pieces to get it running. Regards, Kay leo
Re: Passing arguments
On Sat, 2002-09-14 at 04:16, Luke Palmer wrote:
When a bare closure is defined, it behaves the same as a signatureless
sub. That is, it topicalizes the first argument, and hands them all over
in @_. So your topic passing is just, well, passing the topic, like
any ol' argument.
Ok, thanks. I was getting lost in the noise there, but this finally
makes sense.
Just to make 100% sure though, let me get these definitions clear:
topicalize: To default to C$_ in a prototype (thus acquiring the
caller's current topic).
signatureless sub: A sub that does not specify a prototype, and thus has
a default prototype of:
sub($_//=$_){};
ne?
--
Aaron Sherman [EMAIL PROTECTED]
http://www.ajs.com/~ajs
RE: Passing arguments
Aaron Sherman:
# topicalize: To default to C$_ in a prototype (thus
# acquiring the caller's current topic).
Well, to topicalize a region of code is actually to specify a different
topic, that is, a different value for $_. For example:
$foo = new X;
$bar = new Y;
given $foo {
print $_.type, \n;#prints X
given $bar {
#XXX we're using 'given' for this too, right?
print $_.type, \n;#prints Y
}
}
(An aside: it strikes me that you could use Cgiven as a scoped lexical
alias, i.e.
my $foo=foo;
my $bar=bar;
print $foo;
given $bar - $foo {
print $foo;
}
print $foo;
#prints foobarfoo
Hmm...)
# signatureless sub: A sub that does not specify a prototype,
# and thus has a default prototype of:
#
# sub($_//=$_){};
#
# ne?
More like:
a sub that was created with the arrow (-) or a bare block and
does not specify a prototype, and thus has a default prototype
of:
- ($_ //= $OUTER::_) { };
Or some such. (Maybe C$_ //= $_ will work, but I have reservations
about that--especially about the possibility of that picking up $_
dynamically instead of lexically. In some cases you want $_
dynamically, in others lexically. Perhaps C$_ is topic('lexical') and
C$_ is topic('dynamic')?)
--Brent Dax [EMAIL PROTECTED]
@roles=map {Parrot $_} qw(embedding regexen Configure)
Wire telegraph is a kind of a very, very long cat. You pull his tail in
New York and his head is meowing in Los Angeles. And radio operates
exactly the same way. The only difference is that there is no cat.
--Albert Einstein (explaining radio)
Re: Perl 6 Summary for week ending 2002-09-15
Piers Cawley wrote: Happy birthday to me! Congratulations. ... by my turning 35 on the 15th 44 on 16th - yes Sept. and thanks for the kudos, leo
Regex query
Well, I've started my Perl 6 programming career already and I've got
stuck. :)
I'm trying to parse a Linux RAID table (/etc/raidtab), which looks a
bit like this:
raiddev /dev/md0
raid-level 5
option value
option value
...
device /dev/sde1
raid-disk 0
device /dev/sdf1
raid-disk 1
device /dev/sdg1
raid-disk 2
...
raiddev /dev/md1
...
Here's the grammar I have so far:
grammar Raidtab;
rule raidtab { raiddev+ };
rule comment { sp* \# .* |
# Or a blank line
^^ \n };
rule comm_eol { sp* comment? sp* \n };
rule raiddev { comment*
sp* raiddev sp+ $name := (/dev/md\d+) comm_eol
(devicelayout | option | comment)+ };
rule option { sp* $key := ([a-z]-+) sp* $value := (\w+) comm_eol };
rule devicelayout { sp* device sp+ $name := (/dev/\w+) comm_eol
sp* $type := (raid|spare|parity) -disk sp*
$index := (\d+) comm_eol
};
What I can't figure out is how to drill down into the returned match
object and get at individual devices. I'd expect to be able to say
something like
$matchobject{raiddev}[0]{devicelayout}[1]{name}
and get /dev/sdf1. Is that how it works, with multiply-matched rules
being put into arrays, or is it stored differently somehow?
--
3rd Law of Computing:
Anything that can go wr
fortune: Segmentation violation -- Core dumped
Re: Perl 6 Summary for week ending 2002-09-15
Leopold Toetsch [EMAIL PROTECTED] writes: Piers Cawley wrote: Happy birthday to me! Congratulations. ... by my turning 35 on the 15th 44 on 16th - yes Sept. Congrats to you too. So, should I start maintaining a birthday database for the summaries? Probably not. -- Piers It is a truth universally acknowledged that a language in possession of a rich syntax must be in need of a rewrite. -- Jane Austen?
