Re: Buf.pm: FIFO and grammar
Nicholas Clark wrote: On Thu, Aug 12, 2010 at 03:38:31PM +0200, Carl Mäsak wrote: In fact, jnthn++ had a talk at YAPC::EU the other week where he showed how nested signatures can be used to make hierarchical matches. A proof-of-concept module could simply be some sugar around this already existing functionality. That was a really good talk. I hope that it has been videoed, and will be online soon. I saw a video camera in the room, but not sure when we'll be seeing the footage from that. In the meantime, the slides are at: http://www.jnthn.net/papers/2010-yapc-eu-signatures.pdf Thanks, /jnthn
Re: Buf.pm: FIFO and grammar
On Fri, Aug 13, 2010 at 11:27 AM, Jonathan Worthington
jonat...@jnthn.netwrote:
I saw a video camera in the room, but not sure when we'll be seeing the
footage from that. In the meantime, the slides are at:
http://www.jnthn.net/papers/2010-yapc-eu-signatures.pdf
Nice talk! One minor nit, and perhaps I'm just misunderstanding some subtle
use of the terminology, but you say:
In Perl 5, you get a copy of the arguments to work with in @_.
However, this isn't true (again, unless I'm misunderstanding you). @_ is a
by-reference list of positional parameters (Perl 5 only has positionals)
which are all read-write, which it's interesting to note, is impossible in
Perl 6... well, at least in Rakudo, as I'm not sure what the behavior is
supposed to be, but a slurpy positional list in Rakudo that's declared is
rw does not change the values passed in:
sub foo(*...@_ is rw) { @_[0] = 1 }
my $a = 0;
foo($a);
say $a; # 0
Kind of interesting that you can't easily emulate Perl 5's parameter
passing...
--
Aaron Sherman
Email or GTalk: a...@ajs.com
http://www.ajs.com/~ajs
Re: Buf.pm: FIFO and grammar
My understanding from synopses was that you get the Perl 5 behaviour if
you omit the signature on your function declaration (though I
unfortunately can't check as I don't have Rakudo installed):
sub foo { @_[0] = 1 }
my $a = 0;
foo($a);
say $a; # 0
Cheers...
On Fri, 2010-08-13 at 12:06 -0400, Aaron Sherman wrote:
On Fri, Aug 13, 2010 at 11:27 AM, Jonathan Worthington
jonat...@jnthn.netwrote:
I saw a video camera in the room, but not sure when we'll be seeing the
footage from that. In the meantime, the slides are at:
http://www.jnthn.net/papers/2010-yapc-eu-signatures.pdf
Nice talk! One minor nit, and perhaps I'm just misunderstanding some subtle
use of the terminology, but you say:
In Perl 5, you get a copy of the arguments to work with in @_.
However, this isn't true (again, unless I'm misunderstanding you). @_ is a
by-reference list of positional parameters (Perl 5 only has positionals)
which are all read-write, which it's interesting to note, is impossible in
Perl 6... well, at least in Rakudo, as I'm not sure what the behavior is
supposed to be, but a slurpy positional list in Rakudo that's declared is
rw does not change the values passed in:
sub foo(*...@_ is rw) { @_[0] = 1 }
my $a = 0;
foo($a);
say $a; # 0
Kind of interesting that you can't easily emulate Perl 5's parameter
passing...
Re: Buf.pm: FIFO and grammar
On Fri, Aug 13, 2010 at 8:11 PM, Jon Murray perlsm...@gmail.com wrote:
My understanding from synopses was that you get the Perl 5 behaviour if
you omit the signature on your function declaration (though I
unfortunately can't check as I don't have Rakudo installed):
sub foo { @_[0] = 1 }
my $a = 0;
foo($a);
say $a; # 0
Nope. In fact, as you indicated in the comment you left in, that prints 0
just like the first example. In neither case is $a modified. In Perl 5, on
the other hand, the passed value can be modified:
$ ./perl6 -e 'sub foo { @_[0] = 1 } ; my $a = 0; foo($a); say $a'
0
$ perl -le 'sub foo { $_[0] = 1 } my $a = 0; foo($a); print $a'
1
You might well be correct about how it's supposed to work, but that's
certainly not the current behavior.
On Fri, 2010-08-13 at 12:06 -0400, Aaron Sherman wrote:
On Fri, Aug 13, 2010 at 11:27 AM, Jonathan Worthington
jonat...@jnthn.netwrote:
I saw a video camera in the room, but not sure when we'll be seeing the
footage from that. In the meantime, the slides are at:
http://www.jnthn.net/papers/2010-yapc-eu-signatures.pdf
Nice talk! One minor nit, and perhaps I'm just misunderstanding some
subtle
use of the terminology, but you say:
In Perl 5, you get a copy of the arguments to work with in @_.
However, this isn't true (again, unless I'm misunderstanding you). @_ is
a
by-reference list of positional parameters (Perl 5 only has positionals)
which are all read-write, which it's interesting to note, is impossible
in
Perl 6... well, at least in Rakudo, as I'm not sure what the behavior is
supposed to be, but a slurpy positional list in Rakudo that's declared
is
rw does not change the values passed in:
sub foo(*...@_ is rw) { @_[0] = 1 }
my $a = 0;
foo($a);
say $a; # 0
Kind of interesting that you can't easily emulate Perl 5's parameter
passing...
--
Aaron Sherman
Email or GTalk: a...@ajs.com
http://www.ajs.com/~ajs
Re: Buf.pm: FIFO and grammar
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On 8/13/10 22:03 , Aaron Sherman wrote:
On Fri, Aug 13, 2010 at 8:11 PM, Jon Murray perlsm...@gmail.com wrote:
My understanding from synopses was that you get the Perl 5 behaviour if
you omit the signature on your function declaration (though I
unfortunately can't check as I don't have Rakudo installed):
sub foo { @_[0] = 1 }
my $a = 0;
foo($a);
say $a; # 0
Nope. In fact, as you indicated in the comment you left in, that prints 0
just like the first example. In neither case is $a modified. In Perl 5, on
the other hand, the passed value can be modified:
$ ./perl6 -e 'sub foo { @_[0] = 1 } ; my $a = 0; foo($a); say $a'
0
$ perl -le 'sub foo { $_[0] = 1 } my $a = 0; foo($a); print $a'
1
You might well be correct about how it's supposed to work, but that's
certainly not the current behavior.
As I read the spec, is ref should work (with some caveats). I have no
idea if Rakudo currently implements it.
- --
brandon s. allbery [linux,solaris,freebsd,perl] allb...@kf8nh.com
system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu
electrical and computer engineering, carnegie mellon university KF8NH
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Re: Buf.pm: FIFO and grammar
Oha (): after speaking with masak, i come up with some ideas about Buf i would like to share with you, maybe you can find them usefull http://register.oha.it/buf.pod Just thought I'd weigh in here a bit. Oha's proposal consists of two parts, each of which is interesting in its own right: * The spec already has Buf as a Stringy, Array-ish thing. Perhaps one could optimize for the ways Buf will actually be used, and think up an API that combines the encoding/pushing and decoding/shifting into single operations? * Grammars define a hierarchical structure that seems to be perfect for encoding the packing of larger pieces of data, for example when serializing an object structure. Could one use grammars, or something very much like it, as a modern pack template? While I'm not convinced of the specifics of Oha's proposals, I think the cores of both of these ideas have merit. // Carl
Re: Buf.pm: FIFO and grammar
On Thu, Aug 12, 2010 at 5:47 AM, Carl Mäsak cma...@gmail.com wrote: Oha (): * Grammars define a hierarchical structure that seems to be perfect for encoding the packing of larger pieces of data, for example when serializing an object structure. Could one use grammars, or something very much like it, as a modern pack template? A while back we had a fairly productive conversation about matching regexes on non-textual data: http://groups.google.com/group/perl.perl6.language/msg/24f23fdfc0c5d459?hl=en My proposal there is incomplete, but matching structured data (even if that structure is just a sequence of non-textual bytes) using rules definitely makes sense to me. The real question is: what is the least invasive way to do it? Modifying nqp for this purpose would, I think, not make sense. I think we'd need a pure Perl implementation of the rules engine that could match either text or data, and that's a gigantic undertaking. -- Aaron Sherman Email or GTalk: a...@ajs.com http://www.ajs.com/~ajs
Re: Buf.pm: FIFO and grammar
Carl (), Aaron (): * Grammars define a hierarchical structure that seems to be perfect for encoding the packing of larger pieces of data, for example when serializing an object structure. Could one use grammars, or something very much like it, as a modern pack template? A while back we had a fairly productive conversation about matching regexes on non-textual data: http://groups.google.com/group/perl.perl6.language/msg/24f23fdfc0c5d459?hl=en Interesting thread. My proposal there is incomplete, but matching structured data (even if that structure is just a sequence of non-textual bytes) using rules definitely makes sense to me. The real question is: what is the least invasive way to do it? Modifying nqp for this purpose would, I think, not make sense. I think we'd need a pure Perl implementation of the rules engine that could match either text or data, and that's a gigantic undertaking. Crazy people have been known to implement the rules engine in Perl 6, even... :-) But I think we can get away much cheaper than that. If we contend ourselves with keeping an early sublanguage inside strings, or with some well-chosen subroutine names, we could experiment with hierarchical matchers today in Rakudo. I'd love for someone to develop a proof-of-concept module for something like this; both matching on binary data, and the hierarchy matcher described in your thread. In fact, jnthn++ had a talk at YAPC::EU the other week where he showed how nested signatures can be used to make hierarchical matches. A proof-of-concept module could simply be some sugar around this already existing functionality. // Carl
Re: Buf.pm: FIFO and grammar
On Thu, Aug 12, 2010 at 03:38:31PM +0200, Carl Mäsak wrote: In fact, jnthn++ had a talk at YAPC::EU the other week where he showed how nested signatures can be used to make hierarchical matches. A proof-of-concept module could simply be some sugar around this already existing functionality. That was a really good talk. I hope that it has been videoed, and will be online soon. Nicholas Clark
Buf.pm: FIFO and grammar
after speaking with masak, i come up with some ideas about Buf i would like to share with you, maybe you can find them usefull http://register.oha.it/buf.pod HTH Oha
