Rakudo Star - a useful, usable, "early adopter" distribution of Perl 6 | Hacker News Reader

Rakudo Star - a useful, usable, "early adopter" distribution of Perl 6

rakudo.org

113 pointsavar31 comments

Open articleView on HN

Downloaded it for a quick experiment. Points I've noticed so far:

* It needs perl5 to build.

* Hello World still works.

* Perl can now compete with Java for slow startup.

* One of my pet perl hates, the inability to write "sub foo($a, $b, $c) {" is fixed.

> One of my pet perl hates, the inability to write "sub foo($a, $b, $c) {" is fixed.

I think you're in for a good surprize there, you can even do

subset Even of Int where { $_ % 2 == 0 };

sub foo(Even $a) {say $a;}

foo(2); # prints 2

foo(3); # Constraint type check failed for parameter '$a'

I think I'm falling for perl all over again <3

oh God that looks absolutely delicious.

Yep very scrummy! And its also been available (for methods) in Perl5 for a while as well: http://news.ycombinator.com/item?id=1040614

Here is the perl6 example using MooseX::Declare (http://search.cpan.org/dist/MooseX-Declare/) in perl5:

    use 5.012;
    use MooseX::Declare;

    class Foo {
        use MooseX::Types -declare => [ qw(Even) ];
        use MooseX::Types::Moose qw(Int);

        BEGIN {
            subtype Even, as Int, where { $_ % 2 == 0 };
        }

        method bar ( Even $a ) { say $a }
    }

    my $foo = Foo->new;

    $foo->bar( 2 );  # => prints 2
    $foo->bar( 3 );  # => throws error

This is a cool capability. But I have to admit, it's lacking in the syntactic sugar that made the previous example look so appealing. I just simply read the code out loud in English and immediately knew what it meant. This is a bit more of a tongue twister. This notion of defining subsets of symbols like this could make code correctness for many cases a trivial thing.

Well, can you reasonably expect much else? It's a backported feature from perl6, constrained by the existing syntax of perl5. Of course it won't have the syntatic sugar.

One of the other cool capabilities of perl6 is the rules system, expanding on regexs so you can work with full on grammars. The perl6 grammar, written in perl6:

http://svn.pugscode.org/pugs/src/perl6/STD.pm6

No, I'm simply stating that I really like what they're doing with Perl 6 so far. I'm excited by the new grammar system immensely.

It's clear that doing it in an older syntax is clearly less elegant. However, it's very impressive though that the back ports of Perl 6 features to Perl 5 are proceeding relatively nicely though. The work on Perl 6 has definitely been a boon to 5.

The BEGIN { subtype ... } code is just pure perl/Moose. So its possible for the MooseX::Declare developers to add some extra sugar there.

It goes away as soon as you put the MooseX::Types declaration into its own package. Which one does pretty often, since reusing types and coercions produces more maintainable code in general. The title of that library isn't "Organise your Moose types in libraries" without reason :)

One of my favorite examples of cool Perl 6 code right now is Perl 6 in Perl 6: http://github.com/masak/yapsi/blob/master/lib/Yapsi.pm

One perl6 project that looks very interesting is http://github.com/krunen/xml/

XML parser defined using perl6 grammar rules: http://github.com/krunen/xml/blob/master/lib/XML/Grammar/Doc...

That pet Perl hate was solved a while ago. See http://search.cpan.org/dist/MooseX-Declare/lib/MooseX/Declar...

See also http://search.cpan.org/dist/Function-Parameters for plain function signatures and http://search.cpan.org/dist/Method-Signatures-Simple for non-Moose method signatures.

Function::Parameters looks like more or less what I was looking for, although I continue to think the perl6 option is a little cleaner.

Perl can now compete with Java for slow startup.

That's my next area of focus for Rakudo optimizations.

I built it two weeks ago and I noticed the slow startup too. I'm pretty sure this will improve. It needs to improve because it matters for shell glue. For the rest of the code I'm writing, startup time is a total non-issue.

Thanks so much everyone. Perl 6 has already greatly aided my professional development as excellent features are ported into Perl 5.

I don't know what Perl 6's future will be; I have high hopes. But it's already moved me forward.

Is there a "Try Perl 6" on the web yet? Google is failing me and I'd love to paste one of the grammar examples into a textbox and start playing it; especially since I don't see Windows binaries linked from the article.

There is one being developed, it will be available at try.rakudo.org.

See http://github.com/moritz/try.rakudo.org for the source code.

Not exactly the most optimal way, but you can hop on to the IRC channel #perl6 and run code there using one of many codebots. Admittedly, you are limited to one-liners here. And, your code will be public, so it's not like running in the "comfort of your own session".

You can send private messages to the bot and it will reply to you with the result ... so no problem there.

The one liner limitation still apply, but they can be very loooong one liners ;-)

For windows binaries, go to http://www.jnthn.net/perl6/rakudo/Rakudo-Star-2010-07.msi, which is where I got it. It may no t be the standard location, so I am not sure how long it will be available.

This is now available via the downloads page linked from the announcement, as well.

See http://colabv6.dan.co.jp/lleval.html which includes perl6 among many other languages. Also its already been updated to Rakudo Star!

Thanks to everyone who put this together. This probably sounds silly, but Perl was the first programming language I ever did anything "real" with (it was my second language, after Microsoft QuickBASIC), and no matter how many other languages I try I'll always have a soft spot in my heart for Perl. So it's great to see a real release for Perl 6 which, as it matures, I think will prove itself as the best mainstream dynamic imperative language out there.

EDIT: In particular, I think macros and stm will be killer features with respect to other languages, once they're implemented in Rakudo.

Been waiting for this release to (re)jump back into Perl development. Congrats to everyone involved!

Congrats and huge thanks for all those involved in this release. It is looking awesome.

As a Perl 5 developer I'm really excited about Perl 6. But the reason I won't use Perl 6 for at least the next 3 years is the same reason Ruby isn't my core language for production apps: I'm waiting for it to get really fast and really stable. Ruby is just about there, so I'll probably switch to Ruby in the next year or so. Then 3 to 6 years from now I'll switch to some incarnation of Perl 6 assuming it maintains its momentum and has tangible benefits over Ruby.

I'm not an early adopter. I think startups are risky enough and technology choices are but one point of differentiation in business.

I'm happily using MooseX::Declare for when I want better OO - and given Moose is a full metaprotocol with appropriate, extensible objects for everything (ruby has nothing like attributes, let alone extensible meta-attributes, sadly) it's a hugely powerful tool.

Piers Cawley happily gave up on ruby and came back to perl5 as a result of it - you should give it a play before looking at a more drastic switch.

Perl 6 is awesome. Great work guys.

Reply on news.ycombinator.com