I’ve just released a new version of Method::Signatures: 20121201, a.k.a. yesterday. This one has been a long time coming—I thought for a while there that $work was going to either bury me or sap my will to live—but it’s finally here, and I hope you MS fans out there will be rejoicing. Let’s take a look at some of the goodies.
(By the way, most of these awesome new features came from the Damian, as I described in my post about Git and patches. The remainder come from schwern, who is of course the original author of MS. This time around, I really am just the guy who put it all together and uploaded it for all y’all.)
It was late afternoon of a chill November in Paris. I was walking along the quai, lost in a brown study. Looking up, I saw my friend C. Auguste Dupin approaching me.
"Ah, bon soir, mon ami," said Dupin, "and what brings you beside the Seine on this crisp evening?"
"Something has been puzzling me," I replied, "and I thought the walk would give my thoughts an opportunity to put themselves in order."
"It is a day of puzzlements, no? Will you not share your puzzlement with me?"
"Well," I demurred, "it is a small thing -- probably something I did to myself. But I do not wish to intrude on your time."
"Ah, but it is no intrusion for a friend."
"Well," I said as we turned across the Pont Neuf, "as you know I dabble in Perl, and I like to keep a variety of systems available for testing purposes. I upgraded one of these and was re-installing Perl, when one single module failed to install -- indeed, failed to unpack."
An infrastructure for having “optional” code blocks that can be eliminated prior to execution.
Ideally, these code blocks can be toggled by calling code and then eliminated from the execution tree at the OP level.
In essence, delegate 100% of the “Speed vs Correctness” concern to the consumer of the code, not the implementer.
Presently implemented using dead-code folding mechanisms.
a();
if( 0 ){
/* code */
}
b()
Which becomes
a();
/* noop */
b();
Additionally, this is implemented with perl constant subs so that the if logic is performed at code body compile time, eliminating any run-time penalties from doing the check:
Two weeks ago I mentioned a couple of activities that I found nice to have in the conference. Today I will tell about other things that we already tested during our previous events.
In 2009, at YAPC::Russia in MoscowAlex Kapranov hosted the Game of the Future, where we were trying to predict the future of Perl and related things. There were a few groups that were compiling the future based on probable or improbable events that might happen in a few years, as well as on the known facts. As a result, a mind map was build, which is quite interesting to read today:
You may find a number of region-specific items there but the funniest thing is that we were considering the YAPC::Europe in Kiev an unlikely event at that time.
24pullrequests.com takes the spirit of the Advent coding calendar and puts a new spin on it. Try to send one pull request per day for the next 24 days and 24pullrequests.com will help you track your progress. At the time of writing, 1,224 devs have already signed up.
Some Perl projects are already represented, but there's still room for more. It would be good to see some more Perl projects on the list for participating Perl devs who are looking for something to contribute to.
I've been exploring the Perl::Critic configuration file somewhat, and something struck me as unusual.
It seems fine for using for the usecase of "inherit some predefined set of rules and apply them selectively", which works fine if you just want to adopt some other standard that is pre-existing, and just make minor adjustments.
However, if you're wanting to create policy sets for others to use, it seems poorly suited.
1. Existing Systems
1.1. Severity level
This feature seems confusing.
It looks simple at first, but its problematic for anyone to utilise this to create a large, custom policy set.
The gist I get of reading it is you specify a severity level in your configuration, and policies that are included with a larger severity number than that are used. ie: Specify severity = 2 and items with severity levels 2,3,4,5, will be applied, while rules with severity level 1 are ignored.
The documentations suggest it might be a good idea to manually override the severity level for a plugin, ie:
Last week at the London Perl Workshop, I gave my first ever talk. 20 minutes on the subject of documentation. I'm pleased to say it went very well, and I've had some fantastic feedback from everyone who saw it.
I thought the wider perl community would appreciate having a look at my slides. As always, it would make more sense to hear me talking - but this gives a good idea as to what the talk is about.
If anyone wants to invite me to speak at exotic locations around the world, I am available ;)
...some new stuff for perlybook.org I got an error message and needed quite long to find the cause. This was so unexpected too, because I have not done much changes.
The error message I got:
Unrecognized character \xCD; marked by <-- HERE after og->debug(<-- HERE near column 26 at script/../lib/PodBook.pm line 43.
Here is the code:
Who finds the error first?
Ps: dusty screens will make it harder!
If you have a checkout of the Dancer repository, you'll need to tell git about the new upstream URL - if you had a commit bit, so had a read+write checkout:
A sequence is an ordered list of items, whose items aren't necessarily unique. Perl's arrays are sequences of a finite size:
my @sequence = qw/bar baz ban baz baz/;
A set, however, is an unordered collection of unique items. Perl provides native support for sets in the form of the keys of hashes:
my %set1 = map { $_ => undef } qw/foo bar baz/;
my %set2 = map { $_ => undef } qw/bar foo foo baz/; # Same as above
my %set3 = map { $_ => undef } qw/baz baz bar bar foo foo/; # Also same as above
Because sets are unordered, and contain unique items, the sets formed by the keys of the hashes above are identical. Generally sets are used to test for membership:
my %acceptable = map { $_ => undef } qw/foo bar baz/;
die unless exists $acceptable{ $key };
Set::Scalar provides further useful set operations.
This month featured lots of work in the latter parts of Alien::Base. These improve library detection logic, pkg-config functionality and packlist support.
I was especially pleased to get a bug report filed by bpo regular Toby Inkster. He is writing a provisional Alien::LibXML based on Alien::Base. He noticed some odd behaviors that we are still trying to work out. This feedback led to more improvements than just his, so please keep the bug reports coming!
This month I released three dev versions, the latest being released this evening. I also released Acme::Ford::Prefect again, this time the tests shouldn’t fail on CPANtesters computers who don’t actually install the dependent modules for the one that they are testing. This module is one of the “downstream” modules that are part of the test system for Alien::Base (along with Acme::Alien::DontPanic). These are needed since some of the magic happens during the final installation so tests have to occur AFTER installation of the module in question.
I needed to port a little cgi-script that implements a simple SOAP-server to Plack. After a little searching, I came across SOAP::Transport::HTTP::Plack.
Unfortunately, the documentation of this module is ... not really helpful.
Here's my (slightly modified) cgi-script:
#!/usr/bin/perl
use SOAP::Transport::HTTP;
SOAP::Transport::HTTP::CGI
->dispatch_to(
'/some/directory',
'Some::SOAP::Module1',
'Some::SOAP::Module2',
)->handle;
We've been simplifying some ugly code recently, and De Morgan's laws have come up more than once. A developer on the team complained the Wikipedia entry obscured - from a developer's perspective - the simplicity of these quite useful transformation rules, so, expressed in Perl:
It's short and shouldn't take more than 2-3 minutes of your time.
If you ever shared your software, commited a patch, reported a bug or wrote a blog post on Perl, your opinion matters.
The reasoning behind this survey:
For the Play Perl project to succeed, I need to figure out if there's a demand for this product, and which features will be more important. I've already spent a considerable amount of time thinking about it, and I'll share my ideas about why I'm doing what I'm doing after the survey will be over.
Of course I'm also going to share the aggregated results of this survey for everyone to meditate on.
By the way, Wufoo doesn't allow free accounts for users from my country, so I spent $15 on it. I guess I'm motivated enough :)
So I hope we'll get enough answers, and PLZ RT.
One of my projects for quite a while is to understand Monads. I have been working on this, off and on, for an embarrassing amount of time. Yes, I could have just learned Haskell and that would have done it but I wanted to be a pain in the arse. Also, I had a horrible experience attempting to learn Haskell a long time ago. Thus, I decided as I use Ocaml for most things then I should be able to do it. First, I read this article a few times and this which is really good and helps hugely in my understanding. Anyway, I will take a step by step approach to showing how to write a State Monad for Ocaml.
