technical meeting 26th January 2012

London Perl Mongers organises technical meetings every two months. The technical meetings are a chance to find out what has been going on in the Perl community, what techniques people are using and how Perl integrates with other software.

The next technical meeting will be on the 26th January 2012 from 7pm to 9pm (you may arrive earlier, please sign in at the reception). You have to sign up to attend, see below.

It will be hosted by NET-A-PORTER.COM and held at their offices in Westfield London Shopping Centre. Many thanks to Kristian Flint, NET-A-PORTER.COM and everyone involved for allowing us to use this wonderful venue.

Gianni Ceccarelli - "Dispatch tables" inside regexes and nasty tricks in the name of speed
Paul Makepeace - Ruby cuteness applied to testing & webserving
Zefram - Customising ops for semantic fun and performance profit
Tomas Doran - Using ZeroMQ and Elasticsearch for log aggregation

Lightning Talks

I’m very pleased to announce the Geoff Avery will be reprising his role as Lightning Talk MC for YAPC::NA 2012. Geoff does a great job organizing the Lightning Talk sessions at YAPC, and we’re so glad to have him come to Madison.

If you’ve got ideas for lightning talks, please feel free to submit them in advance.  

[From the YAPC::NA Blog.]

Thank you, CPAN Testers

Today I just want to thank you to all CPAN Testers. I do not know if there are such initiatives for other programming languages, but you are awesome. So many architectures, so many operating systems, so many Perl versions.

I hope to help someday. I just need to find some time for it.

Thank YOU all!

Reading QR Codes with Perl

Reading QR Codes with Perl :

As a response to our post on QR Codes at YAPC::NA 2012, oylenshpeegul came up with a way to read QR Codes with Perl.

[From the YAPC::NA Blog.]

How to install into 5.6.2

Contrary to popular belief you can install almost all CPAN packages under 5.6.2.

First Step:

Set the urllist in your ./cpan/CPAN/ to and rm ./cpan/Metadata and the 3 outdated sources/authors/01mailrc.txt.gz sources/modules/02packages.details.txt.gz sources/modules/

Then start installing.

There are a couple of authors who agressively used to boycott 5.6 in their dependencies (schwern, dagolden, kenwilliams, rsignes), but it is quite easy to fix this. So after a couple of refused installations do this:

cd .cpan/build
grep 'use ExtUtils::MakeMaker' */Makefile.PL
sed -i 's/use ExtUtils::MakeMaker 6.3[0-9];/use ExtUtils::MakeMaker;/' \

Module::Build can also be installed (0.34), DBI (1.604), Moose (0.40), DateTime (0.66) and many more. january technical meeting

Cross posted from my github blog post

Developing parsers incrementally with Marpa

Marpa::XS is a general context-free parser. What does that mean? For a grammar writer, it means that he doesn't need to worry that the next rule he adds to the grammar is the one that makes it hit the invisible wall that most other parser generators set up. If you can write it in BNF, Marpa will parse it. Which makes Marpa::XS good at incremental development.

As you develop your Marpa grammar, you can track the tradeoffs you are making between features and efficiency. Chances are, if your grammar is unambiguous or lightly ambiguous, there are no tradeoffs -- you're getting everything you want in linear time. Marpa is linear for every class of grammar currently in practical use.

Marpa is also linear with many ambiguous grammars and, in the worst case, Marpa's time complexity is what is accepted as optimal in practice. Whatever the time complexity that you're seeing with Marpa, it's probably as good or better than you're going to get from another parser generator.

One way to start the semantics

Five Months To Go

I hope you’re enjoying your New Year so far. Did you make a resolution to come to YAPC::NA 2012

The dates are June 13-15. The place is Madison, WI. 

And don’t forget to invite your spouse to attend our Spouses Program.

[From the YAPC::NA Blog.]

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