blogs.perl.org

Hi Folks

Back in 2005 I offered to host HTML and text versions of the BNF syntax for various SQL dialects, prepared by Jonathan Leffler.

He has just sent me updated versions of those docs, which are available on this page.

Cheers
Ron

We all know that Python, Perl and Ruby (ok, and PHP, and probably other languages) are always stealing ideas from one another. This is a nice thing to do.

After programming a few with Python there is a couple of details I like. I know not all are possible to implement in Perl. Some of them are, and I would love if they were. I know not all people agree with me (that good, too). Nevertheless, I present here a couple of ideas.

Although I do not like relying only in indentation for blocks, I like the fact that conditionals and loops does not need parenthesis. It makes the code much more legible. I imagine that to make this in Perl it would be crazy. Good enough we don't need them when using it as a modifier.

You're going to go to the Moose Hackathon? You arrive in Frankfurt a few days before the event? Then you might want to do something in Frankfurt. We've set up a wiki page with some suggestions...

Hold on to your hats, this is going to be a wild ride! See you all at the Lowell Center for the kick off this morning at 9am sharp! Registration opens at 7am.

Don’t forget that you can watch the streams live on the web for free:

• Lowell Dining Room (Main Hall / Perl in the Wild)
• Pyle 325 (Perl 101 / Beginners Track)
• Pyle 313 (Anything Goes)
• Pyle Vandenburg Auditorium (Anything Goes)

Also, the videos are being recorded. We will be posting them somewhere, but we don’t have details yet. We’ll do another blog post after the conference to let you know where you can watch them.

[From the YAPC::NA Blog.]

Unicode is getting ready to release their next version, 6.2 (likely in September). It includes only a single new character, for the new Turkish currency symbol. But there are changes to the properties of existing characters, and some of these may be of concern to Perl programmers.

A comment period on the changes has just started, closing in July. Unicode calls these PRI's, or Public Review Issues. This is a link to the page describing the changes and procedures for commenting.

The issues I think are of most interest to Perlers are the proposed changes of the Unicode General Category for a number of ASCII characters. Follow this link for a list of them. An example is U+0040 ( @ ) COMMERCIAL AT. Unicode proposes to change this to be a Symbol, instead of Punctuation. Perl code is somewhat shielded from this change, as qr/[[:punct:]]/ matches both Symbols and Punctuation in the ASCII range. However, what qr/\p{Punct}/ and qr/\p{Symbol}/ match would change, as would qr//[:punct:]]/ for non-ASCII characters.

There are other changes proposed as well. Use the first link above to get the details.

I just have released the latest version of MooseX-App - a command line-app helper framework - on CPAN (see my last blog post if you want to learn more about MooseX-App). This release incorporates the feedback I have got from fellow perl mongers.

The most notable change is that not all attributes will be exposed to the CLI, but only those defined with the new 'option' keyword.

The 'option' keyword is basically just syntactic sugar for adding an attribute with a special trait which marks attributes as command-line options. The main advantage for this approach is that you don't have to explicitly prevent internal attributes - possibly originating from consumed roles deep down in your code - from being exposed to the command line.

Furthermore I have cleaned up the meta classes, making it easier to write custom plugins which can modify almost every part of MooseX-App's behaviour, and fixed a couple of bugs I have discovered while switching App::iTan from MooseX::App::Cmd to MooseX::App.

App::iTan is a little command-line application - written a couple of years ago - which helps me to manage indexed transaction authentication numbers (iTAN) for my online-banking account. Hope you like it.

Part of the reason I love Perl is that it has full closures. It makes it really easy for my scientist brain to think of code references as equations. This is why I try to make my scientific software think this way too; PerlGSL is built on this concept. Its especially fun when this allows me to nest functionality to get even more complex behavior.

In this following example I find the Gaussian width needed so that the integral over it on a certain range has a particular value. Yes this is an easier example, but if the function f were more complex, this code would be no worse.

Hopefully this shows some of that power, and some of the reason I am working on PerlGSL.

I will be going into more detail on similar concepts at one of my talks at YAPC::NA later this month. See some of you there?

If you’re here and want to get a head start on registration, we’ll have an open registration session between 4pm and 6pm tonight in the Upper Lounge of the Lowell Center. Come say hello, pick up your badge, t-shirt, and other swag.

[From the YAPC::NA Blog.]

App-ArchiveDevelCover now shows a diff-like comparison between the current and previous archived coverage report.
You can find a screenshot and a bit more info on my blog

Actually, the payments have been open for about a week or so, but only inofficially. So, if you have registered but not paid for your ticket you can now do so at

http://act.yapc.eu/ye2012/purchase

If you haven't registered yet, you can register there or register on the main site at http://yapc.eu/2012.

OK, so this is my first attempt to write a blog, I hope this works. I like Perl (a lot) I like Bioinformatics and Computational Biology (yes I'm a biologist and I'm also a systems analyst), and now I decided that I like Big Data as well. Hope to write a little about those subjects.

The Spouse’s Program begins tomorrow morning. Those of you participating should come to the opening ceremonies at 9am at the Lowell Center, where I’ll introduce you to our Spouse’s Program organizer, Julia. Dress casually and in comfortable shoes. 

Tomorrow you’ll be taking tours of the State Capitol, Camp Randall Stadium, and of Wollersheim Winery. Later in the week you’ll be visiting the Chazen Museum of Art, going sailing, participating in a craft workshop, and taking a guided tour of State Street (a shopping/restaurant district). 

[From the YAPC::NA Blog.]

Writing fault-tolerant programs can be a tedious exercise. Often, each step in the program logic depends on the success of the step prior, resulting in deeply nested calls to eval. Tracking the global $@ and ensuring that errors are not lost can be tricky and result in hard-to-follow logic.

I recently read The D Programming Language by Andrei Alexandrescu (which I highly recommend). D features an interesting (and, to the best of my knowledge, unique) alternative to try/catch-style error handling (although it also supports try/catch/finally). It turns out that very little code actually traps errors and makes decisions based on error conditions. In most cases, the error must be temporarily trapped to allow cleanup before re-throwing the error afterward. In these cases, D programmers can use a scope statement to register clean-up code to be executed should any of the statements following it trigger an error.

Since YAPC::Asia Tokyo 2010, we have been hosting voting on "Best Talk Award" for talks that go on YAPC::Asia Tokyo. We are also giving away prizes for the winners of these awards -- for 2010, we gave a Macbook Pro with all the bells and whistles, and last year we gave a dandy ergonomic chair.

So we were thinking what to do this year... and here's what we got: We're going to give the winner a trip to YAPC::NA or YAPC::EU. Runner-up prize will be trips to local PM meetups in Japan.

This award was originally created in hopes that giving talks at YAPC::Asia Tokyo will also also be rewarding for the attendees, and also to give them some incentive to learn more, to do more. We believe that giving them a chance to attend these conferences will be an extremely cool opportunity to mingle with people who otherwise they may never meet in person, and to feel what it's like in other conferences.

Of course, we are assuming that a Japanese local would get the award, but if somebody living abroad gets this award, we'll try to arrange something. Do visit us if you're interested!

(This is probably intuitively obvious to everyone else...)

Here is a sample Log::Log4perl configuration where the root logs at WARN, package 'Joe' logs at 'INFO', and package 'Zoe::Marie' logs at ERROR:

log4perl.rootLogger=WARN, LOGFILE log4perl.logger.Joe=INFO, LOGFILE log4perl.logger.Zoe.Marie=ERROR, LOGFILE

log4perl.additivity.Joe = 0
log4perl.additivity.Zoe.Marie = 0

log4perl.appender.LOGFILE=Log::Log4perl::Appender::File
log4perl.appender.LOGFILE.filename=/tmp/test-Log4perl.log
log4perl.appender.LOGFILE.mode=append

log4perl.appender.LOGFILE.layout=PatternLayout
log4perl.appender.LOGFILE.layout.ConversionPattern=[%r] %F %L %c - %m%n

Because of how Log::Log4perl was built, you don't need to do anything special in your code to support this multi-level priority logging -- each package can just use Log::Log4perl->get_logger() to get the the logging object and it all falls out in the wash.

(In theory, this type of configuration should work for Log4j and Log4net also.)

From guest contributor Matt Trout:

YAPC::NA isn’t just about the main conference programme - there’s often
things that get organised on the fly by attendees because somebody comes
up with an idea, or because they want to try somewhere new for lunch.

In order to make sure you don’t miss out - and to find out if somebody
has found the power cable you accidentally left in the lobby - it’s worth
keeping in touch.

To do that, there are two key resources -

 1) The mailing list:

    http://mail.pm.org/mailman/listinfo/yapc

 2) The IRC channel:

    #yapc on irc.perl.org (which allows mibbit.com if you have no client)

The mailing list tends to be used for “hey, does anybody fancy doing
X later?” ideas, and the IRC channel for “hey, does anybody fancy doing
X right now?” but that’s more down to the technology than any enforcement.

These will help you get the most out of your YAPC - and to find the
people involved in http://act.yapcna.org/2012/wiki?node=HallwayPlusPlus
if you’re wanting to met new people while you’re here too!

[From the YAPC::NA Blog.]

To better fit CPAN's naming conventions, Reddit::API has been renamed to Reddit::Client. As there are no dependencies in the reverse lookup graph, Reddit::API is scheduled for deletion.

Reddit::Client begins its life at 0.02 with mostly complete unit tests (thanks for the footnote, Gabor), some refactoring, and a few bug fixes. Enjoy!

YAPC::Asia Tokyo 2012 is now accepting talk proposals!

If you would like to participate in the World's Largest YAPC, now is your chance!

As far as I know, the YEF did receive neither a Letter of Intent nor a proper proposal for hosting YAPC::Europe 2013 yet (and I should know, as I'm on the Venue Committee)

The deadline for submitting a proposal is Thursday, 5 July.

So if you and your group are thinking about hosting next years YAPC, we would very much appreciate it if you'd send a short note (or a full-fledged proposal) to venue@yapceurope.org.

It's really not much work, and all reports from previous organizers stating otherwise are grossly exaggerated!

Here's the whole Call for Venue, and here is a detailed document on what to do to bring YAPC::Europe 2013 to your wonderful hometown. And for even more organizers know-how, check out Perl Jam an upcoming book about "How to organise a conference ... and live to tell the tale." by barbie et.al. (also available on github)