r26976 - docs/Perl6/Spec
Author: lwall
Date: 2009-05-31 08:09:18 +0200 (Sun, 31 May 2009)
New Revision: 26976
Modified:
docs/Perl6/Spec/S11-modules.pod
Log:
[S11] introduce declarators need and defines, components of use
Modified: docs/Perl6/Spec/S11-modules.pod
===
--- docs/Perl6/Spec/S11-modules.pod 2009-05-31 05:17:56 UTC (rev 26975)
+++ docs/Perl6/Spec/S11-modules.pod 2009-05-31 06:09:18 UTC (rev 26976)
@@ -12,8 +12,8 @@
Maintainer: Larry Wall la...@wall.org
Date: 27 Oct 2004
- Last Modified: 26 Mar 2009
- Version: 27
+ Last Modified: 30 Mar 2009
+ Version: 28
=head1 Overview
@@ -154,6 +154,52 @@
tags as arguments to Cis export. (Of course, mixing incompatible scoping
in different scopes is likely to lead to confusion.)
+The Cuse declaration is actually a composite of two other declarations,
+Cneed and Cdefines. Saying
+
+use Sense common @horse;
+
+breaks down into:
+
+need Sense;
+Sense defines common @horse;
+
+=head2 Loading without importing
+Xneed
+
+The Cneed declarator takes a list of modules and loads them (at
+compile time) without importing any symbols. It's good for loading
+class modules that have nothing to export (or nothing that you want
+to import):
+
+need ACME::Rocket;
+my $r = ACME::ROCKET.new;
+
+This declaration is equivalent to Perl 5's:
+
+use ACME::Rocket ();
+
+=head2 Importing without loading
+Xdefines
+
+The importation into your lexical scope may also be a separate declaration
+from loading. This is primarily useful for modules declared inline, which
+do not automatically get imported into their surrounding scope:
+
+my module Factorial {
+multi fact (Int $n) is export { [*] 1..$n }
+}
+...
+Factorial defines 'fact'; # imports the multi
+
+Despite having the form of an infix operator, this form functions as
+a compile-time declarator, so that these notations can be combined:
+
+role Silly {
+enum Ness is export Dilly String Putty;
+} defines Ness;
+
+
=head1 Runtime Importation
Importing via Crequire also installs names into the current lexical scope by
@@ -188,16 +234,13 @@
You may also import symbols from the various pseudo-packages listed in S02.
They behave as if all their symbols are in the C:ALL export list:
-use CONTEXT $IN $OUT $ERR;
-require CALLER $x $y;
+CONTEXT defines $IN $OUT $ERR;
+CALLER defines $x $y;
# Same as:
# my ($IN, $OUT, $ERR) ::= ($*IN, $*OUT, $*ERR)
# my ($x, $y) := ($CALLER::x, $CALLER::y)
-As pseudo-packages are always already preloaded, Cuse and Crequire will
-never attempt to load, for example, CCALLER.pm from an external source.
-
=head1 Versioning
When at the top of a file you say something like
Re: r26976 - docs/Perl6/Spec
=head1 Runtime Importation Importing via Crequire also installs names into the current lexical scope by @@ -188,16 +234,13 @@ You may also import symbols from the various pseudo-packages listed in S02. They behave as if all their symbols are in the C:ALL export list: -use CONTEXT $IN $OUT $ERR; -require CALLER $x $y; +CONTEXT defines $IN $OUT $ERR; +CALLER defines $x $y; Strange... you changed the examples to not be called require, but left the intro as Importing via require... ? --John
Re: The game of life
yary not.com-at-gmail.com |Perl 6| wrote: That was a big part of it... I'm glad Mark posted the APL snippet because it got me to finally read up on the language that's been at the back of my mind. Plus it's useful for p6 language discussion. APL (and a successor, J) may still have a few tricks to lend. Have you come across my Meditations on Perl taken from concepts in APL http://www.dlugosz.com/Perl6/web/APL.html? http://www.dlugosz.com/Perl6/web/APL.html Thinking about who needs loops? was inspirational to me. And it inspired the need for a column-reduce meta syntax. It would be difficult to make macros for each op that don't step on each other, so an extensible way really needs to be inspired.
Re: The game of life
yary not.com-at-gmail.com |Perl 6| wrote: Though I'm not quite sure that S03 covers some of the different-dimension cases. my @table= (1,2,3; 4,5,6); # is this the syntax to create 2d array? No, the Capture on the right, although a Capture of Captures, will be flattened in the list context provided by list assignment. my @table= [1,2,3],[4,5,6]; will give you a Perl5-like array containing arrays for elements. To give a true multi-dimensional array, you must declare it. Although the lengths don't have to be fixed, you at least need the number of dimensions (which could involve ** so the dimensionality could be variable). my @table[2;3]; I pondered over feeding it another list of items in my APL essay. I figured an iterator over the 2-D array should visit the elements in order. So, use that to reshape the simple list. --John
Module Library - aka CPAN
Before joining in the previous CPAN threads, here are some personal wish lists regarding what the perl6 version of CPAN should do. But in order to get some distance from CPAN, I want to call it the Module Library system. Some of the debate threads impact on the internal software environment, and here I think the internal and external environments must be designed in harmony. A library paradigm is different from an archive paradigm, although a library is a form of archive. However, a library is a single place to go to obtain information. It is set up to enhance searching and finding. An archive is a place where things are stored; the users of an archive know what and where they are storing. Hence the difference between an archive and a library is a set of assumptions about what a user knows. Archives are essential for large libraries (often called stacks), but there must be standardised metadata about what is in each archive for it to be useful for a library. So my wish list. I would like: 1) a single place to go for modules that will help me solve programming problems; 2) a variety of ways to look through modules and the information on them - reviews, documentation, dependencies - so that I can choose between them and know what a choice entails; 3) a variety of classifications of modules and module contents that can lead me to modules which may achieve what I want but are named in a manner I did not expect, or contain functionality I could use in another context; 4) a means to extract from the library the module(s) I want, (better still only the parts of the module) and all their dependencies; 5) the ability to access existing CPAN perl software. Extending the library paradigm, there are generalist libraries, which only contain commonly requested books, and specialist libraries and also libraries in other languages. However, good libraries share systems for requesting books from other libraries, even if they are not stored locally. The difference between libraries then boils down to the metadata available to the user, eg., more accessible user catalogs, librarians who know about subjects and can point to related books, etc. The library paradigm breaks down somewhat for software because there is an intimate link between my environment and the software I choose. Hence, it is important to consider the internal environment (my computer) as well as the external environment (the module libraries). Not only is there the problem of different operating systems (*ix, windows*, mac, etc), there is also the possibility of outdated software installed, eg., different versions of languages, such as perl 5.8, perl 5.10. Within my environment, there are multiple possible locations for different aspects of software, eg. binaries, configuration data (which can be global to all users and local for a single user), documentation, data, results. In a corporate environment, these locations may exist across a network. For example, documentation may be on a server, binaries and local configuration data on the local computer, results posted to a web site, input data taken from a database. My wish list for the internal environment; I would like: 1) a single system to manage all my software modules; 2) a method to see where different aspects of software are located, and to change them; 3) an ability to manage in parallel different dependency hierarchies (such as might result from a need to use modules from different generations (eg. perl 5.8 and 5.10). 4) a comprehensive method to determine what my local environment is, so that I can see whether it matches the environment required by software that I want to download, and if not, what I need in addition to be able to run the software. Some commentary on the above: I use the CPAN archive, CPANPLUS, and synaptic (a GUI frontend to the apt tools) for perl since I use Ubuntu/Gnome. In some cases I have to load binaries using synaptic because I cant get the sources to compile properly from CPAN. I do not have the time or inclination to discover why. The result is a mishmash of dependencies. Moreover, I cannot get updated software without breaking something. This occurred when the one Ubuntu generation was distributed with perl5.8 even though perl5.10 was out, and I really wanted to use some of the new software. The result was that I had both 5.8 and 5.10 modules. Although most things worked, perldoc wasnt recognised by some Configure scripts. I am not interested now in discovering the reason. I use this simply as an example about how multiple distribution channels that make different assumptions can lead to problems. But because there is no single method for monitoring the perl environment, it is difficult to solve some of the problems. The current setup works extremely well, except when it doesnt. My difficulty is finding out how to solve the problems that occur. So I think there should be a system that
Re: Illustration of stuff we've been discussing
On May 28, 2009, at 10:27 , John M. Dlugosz wrote: Daniel Ruoso daniel-at-ruoso.com |Perl 6| wrote: Em Qui, 2009-05-28 às 00:24 -0500, John M. Dlugosz escreveu: Please see http://www.dlugosz.com/Perl6/web/info-model-1.html and talk to me about it. The illustratino is cool, but it doesn't take into account the possibility of: @a[0] := $x; Where in the synopses does it say anything like that is possible? := is applied to a _name_. The usual example in the Synopses is with a hash instead of an array, but the same principle applies: %ax := $y; -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: Module Library - aka CPAN
Richard Hainsworth richard-at-rusrating.ru |Perl 6| wrote: Once a module has been decided on, you look to see if there is a binary that matches your internal environment. If not, you have to roll your own from source. Why not have it generate the binary for you, and safe it for future users? It can cross-compile things if needed, or draw upon a network of different kinds of machines that are registered to allow that. Something similar is used for testing modules, right? --John
Re: Module Library - aka CPAN
Dont think this is workable. If the local environment is non-standard, requiring your own solution, then where would you store the binary? And how would you inform future users sufficiently about the local environment for them to access the binary. Besides for most binaries, it is not really a time or space issue to create the binary locally. Mind you, the mindset for a unix person is different to a Windows person. There is a form of linux - gentoo - in which everything is compiled from scratch. In windows, compilation of modules is extremely rare. Richard John M. Dlugosz wrote: Richard Hainsworth richard-at-rusrating.ru |Perl 6| wrote: Once a module has been decided on, you look to see if there is a binary that matches your internal environment. If not, you have to roll your own from source. Why not have it generate the binary for you, and safe it for future users? It can cross-compile things if needed, or draw upon a network of different kinds of machines that are registered to allow that. Something similar is used for testing modules, right? --John
Re: Amazing Perl 6
On May 27, 2009, at 13:59 , Daniel Carrera wrote: Wow... That's a foldl! In a functional language, that would be called a fold. It's very popular in Haskell. I like that Perl 6 seems to be taking steps in the direction of functional languages. First lazy lists (0..Inf) and now a fold. :-D One of the early P6 prototypes was written in Haskell, and there's been a lot of notions lifted from it. (OTOH being an old phart I know [OP] @list as op/list :) -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: Amazing Perl 6
On May 27, 2009, at 15:42 , Daniel Carrera wrote: Mark J. Reed wrote: Note that of the examples given, only Perl 6 and Common Lisp do two things that help immensely simplify the result: 1. reference the built-in * operator directly, without having to wrap it in a lambda expression; 2. actually name the function ! Yes, very neat. Haskell does that too, but I don't know if you can make the function a postfix in Haskell. Not in H98, but ghc allows it as a degenerate form of section. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: Amazing Perl 6
On May 27, 2009, at 18:05 , John M. Dlugosz wrote: And APL calls it |¨ (two little dots high up) buh? Metaoperator / (+/LIST). -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: Amazing Perl 6
On May 28, 2009, at 06:43 , Jon Lang wrote: What I'm wondering is how the list knows to feed two items into '[+]'. While 'infix:+' must accept exactly two arguments, '[+]' can accept an arbitrarily long (or short) list of arguments. I thought that at first too, then remembered a discussion about generalizing the meaning of square brackets and how [op] fell out of it automatically to take a reference to an operator without using the infix:op syntax. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: Amazing Perl 6
On May 29, 2009, at 15:43 , John M. Dlugosz wrote: Care to try ☃ ? That's alt-meta-hyper-doublebucky-cokebottle. *puzzled as to why OSX Character Map thinks that's related to 雪* -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: Amazing Perl 6
On May 29, 2009, at 21:50 , Timothy S. Nelson wrote: some Linux programs support it too. Unfortunately my e-mail program (Pine) seems to have some trouble with unicode -- I may have to look at alternatives after 14 years of use :(. http://www.washington.edu/alpine/ -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: Amazing Perl 6
On May 29, 2009, at 22:40 , Timothy S. Nelson wrote: On Fri, 29 May 2009, John M. Dlugosz wrote: Ah yes, on the PC historically you hold down the ALT key and type the code with the numpad keys. At least when I used it, this was a decimal, rather than hex number, and had to be preceded by a 0 (zero). I see ALT+ a lot in Windows stuff, and have used it a few times (that is, while holding Alt type + and 4 hex digits). -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: renaming or adding some operators
On May 29, 2009, at 22:33 , Jon Lang wrote: also is an ordered, short-circuiting version of (and thus all). For some time now, I've wanted an analog for '|' and 'any' - but the only name I can think of for it would be 'else', which has some obvious clarity issues. I have seen x (alt. y) used in print, so maybe alt? -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: renaming or adding some operators
On May 30, 2009, at 15:38 , Larry Wall wrote: Perhaps something like use *; should pull in all the Unicode operators. Which if course means that any golfing would start with *; ⨷ perhaps? It only makes sense that a Unicode operator be used to pull in all of Unicode. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon universityKF8NH PGP.sig Description: This is a digitally signed message part
Re: renaming or adding some operators
Brandon S. Allbery KF8NH allbery-at-ece.cmu.edu |Perl 6| wrote: ⨷ perhaps? It only makes sense that a Unicode operator be used to pull in all of Unicode. Bravo. If you can't type that, you won't find it useful!
Re: The game of life
Em Qui, 2009-05-28 às 00:26 -0500, John M. Dlugosz escreveu:
Mark J. Reed markjreed-at-gmail.com |Perl 6| wrote:
Perhaps Perl 6 should not aspire to the expressiveness of APL. :) As
nice as it is that you can write Conway's Life in a one-liner(*), I
think that a little verbosity now and then is a good thing for
legibility
(*) life ←{↑1 ω⌵.^3 4=+/,‾1 0 1◦.ϕ⊂ω}
So how would that translate to Perl 6? Both as an exact translation,
and how to do it better in a Perl way?
I didn't try to translate it, but rather I simply tried to implement it
in a way rakudo already runs So... here's my shot!
CODE
class Game {
# XXX: rakudo doesn't know how to initialize arrays properly yet.
has $.seed;
has $.width;
has $.height;
multi method generation(Int $generation where 0) {
return @($.seed);
}
multi method generation(Int $generation) {
my @previous = self.generation($generation - 1);
my @new;
# XXX: rakudo doesn't autovivify arrays properly yet.
@new.push: [] for ^$.width;
for ^$.width X ^$.height - $x, $y {
# XXX: there's an extra set of parens for rakudo
my $value = [+] map { @previous[$^i][$^j] },
((grep { 0 = $_ $.width }, ($x-1)..($x+1))
X
(grep { 0 = $_ $.height }, ($y-1)..($y+1)));
if @previous[$x][$y] 2 = ($value - 1) = 3 {
@new[$x][$y] = 1;
} elsif !...@previous[$x][$y] $value == 3 {
@new[$x][$y] = 1;
} else {
@new[$x][$y] = 0;
}
}
return @new;
}
}
my $game = Game.new(
:width(15), :height(15),
:seed([
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0 ],
[ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0 ]
]));
my @g = $game.generation(4);
say .perl for @g;
/CODE
I guess my mindset is too much imperative for me to think in a more
elegant solution...
daniel
