I've just added a small tie() example to the perlito5-in-the-browser page.

This was implemented today, and it only supports a few methods for now.

tie() does not make perlito5 any slower - the tied containers use a separate class, while the non-tied perl5 containers are javascript native array and hash objects.

nbody - unboxed inlined arithmetic 2x faster

In the first part I showed some problems and possibilities of the B::C compiler and B::CC optimizing compiler with an example which was very bad to optimize, and promised for the next day an improvement with "stack smashing", avoiding copy overhead between the compiler stacks and global perl data.

The next days I went to Austin to meet with the perl11.org group, which has as one of the goals an optimizing compiler for perl5, and to replace all three main parts of perl: the parser, the compiler/optimizer and the vm (the runtime) at will. You can do most of it already, esp. replace the runloop, but the 3 parts are too intermingled and undocumented.

So I discussed the "stack smashing" problem with Will and my idea on the solution.

1. The "stack smashing" problem

B::CC keeps two internal stacks to be able to optimize arithmetic and boolean operations on numbers, int IV and double NV.

Recently on stackoverflow, I answered a question that I thought worthy of a highlight here on the blog. In this forum we all know that one should never parse HTML with a regex, but if we agree on that, there are still many options available afterward. The question as posed was given some HTML, remove all <style> tags and contents. The question was later amended to include that he needed to also remove <style> tags with attributes (the nail in the regex coffin) and <link> tags to stylesheets.

While you could use an XML parser or an HTML tokenizer, personally I like using the Mojo::DOM parser. This is a Document-Object Model interface to your HTML and it supports CSS3 selectors, making it really flexible when you need it. The original problem is solved as easily as:

Berlin.pm is glad to announce that the 15th German Perl Workshop is going to happen in Berlin from March 13th to 15th 2013.
Thanks also to the people of Frankfurt.pm who support us in organizing. More details will follow.

• Using $a and $b outside of sort() can have serious consequences.
• You can't name a subroutine m, q, s, y (at least my favorites f and g aren't taken).
• Removing duplicate elements from a list: PHP:

  php> $ary = array_unique($ary);

  Perl:

  $ sudo su
  # apt-get install curl
  # curl -L http://cpanmin.us | perl - --self-upgrade
  # cpanm List::MoreUtils
  perl> use List::MoreUtils qw(:all);
  perl> @ary = uniq @ary;
  

Anybody care to add?

Data::Dumper version 2.136 was just uploaded to CPAN. It's been over a year since the latest stable release of the module. Generally, I just synchronize changes to the module from the Perl core to CPAN releases and do so very carefully with lots of development releases.

Recently, however, there was a reason to look at Data::Dumper performance critically. A very simple change meant a speed-up of the order of 50% on my test data set. In a nutshell, Data::Dumper used to track each and every value in the data structure just in case you were going to want to use the Seen functionality. That pertains to a tiny fraction of all Data::Dumper uses and everybody was having to pay for it. For example, if you're using the functional interface (like most), then you wouldn't even ever get access to that information, yet everything was being tracked instead of just things with high reference counts.

LinkedIn recently changed its endorsements so that you can target specific skills in your connections. I was presented with some prompts that I found amusing, as if the entire universe already knew this:

Of course, LinkedIn is a trust network. Things like these endorsements, or the CPAN Developers Group and the Advanced Perl Users Group, let someone outside the Perl universe know one person inside then discover trustable people they don't know. With so many companies looking hard to find good Perl programmers, your endorsement might be able to help a friend who's a good programmer but not highly discoverable.

I was amused at a few other possible endorsements. Does Randal Schwartz know Perl?

Is Damian Conway good at public speaking? I can endorse him, although they don't have a button for "Everyone else should just give up":

Right after I finished my LinkedIn tasks, I watched Rachel Botsman's "The Currency of the New Economy is Trust" TED Talk, which just happened to be next in my podcast feed. She mentions Stackoverflow:

My name is Kevin Carillo. I am a PhD student currently living in Wellington (New Zealand) and I am doing some research on Free/Open Source Software communities.
If you have joined the Perl community within the last 2 years, I would like to kindly request your help. I am interested in hearing from people who are either technical or non-technical contributors, and who have had either positive or negative newcomer experiences.

The purpose of the research is to work out how newcomers to a FOSS community become valued sustainable contributors.

You can complete the survey via my university's survey platform. For more detail on the project aims, see below.

What is the project about?
I am basically studying how the experience of a FOSS community newcomer has an influence on this person’s actions and project contributions in the community.

From ohloh.net:

I'm thinking no. Yes, Perl hasn't gained market share. It tends to stabilize these last three years, see especially if you see the contributors graph. But Perl was way too popular back then anyway, due to lack of alternatives for web languages (which is bad, in some ways). Come to think of it, there should be a lot more PHP and JavaScript developers than Perl developers, right?

I am, somewhat famously, one of the last holdouts in the Perl community when it comes to moving away from svn to git.

I fought against the most for a long time, on the basis that the tool support for git on Windows was just terrible and it would make contributing to Perl difficult for Windows people.

Fortunately, with the availability of tools like SmartGit and GitHub for Windows this is no longer a problem.

So it looks like the time has for me to start the giant job of moving my repository over to GitHub myself (no small task considering it contains something like 300 modules).

As a first step, I am porting my personal release automation over to allow me to release modules from GitHub directly without the need for git client integration or a checkout at all.

The core of this new release automation is my new GitHub::Extract module.

> dmake
C:\CPANTE~1\PERL51~1.1\site\lib\auto\MINGW-~1.2\bin\gcc.exe -c  -IC:\CPANTesters\archives\db-4.8.30-mingw32\include\db  -DNDEBUG -DWIN32 -D_CONSOLE -DNO_STRICT-DPERL_TEXTMODE_SCRIPTS -DUSE_SITECUSTOMIZE -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -D_USE_32BIT_TIME_T -DHASATTRIBUTE -fno-strict-aliasing -mms-bitfields -O2           -DVERSION=\"1.827\"   -DXS_VERSION=\"1.827\"  "-IC:\CPANTesters\Perl5.16.1\lib\CORE"  -D_NOT_CORE  -DmDB_Prefix_t=size_t -DmDB_Hash_t=u_int32_t version.c
In file included from C:\CPANTesters\archives\db-4.8.30-mingw32\include\db/db.h:30:0,
                 from version.c:30:
c:\cpante~1\perl51~1.1\site\lib\auto\mingw-~1.2\bin\../lib/gcc/mingw32/4.6.2/../../../../include/pthread.h:612:3: error: expected identifier before numeric constant
dmake.exe:  Error code 129, while making 'version.o'

enum {
	PTHREAD_CREATE_JOINABLE       = 0,
	...
};

The actual intention behind perlybook.org was to make module documentation from CPAN more portable. Ebook-Readers today are designed for reading-pleasure everywhere - in your garden at daylight or in your bed at night... and this works so far.

But recently I noticed an effect which could also be of interest for "normal" Perl programmers who just work at a the computer and also prefer reading the docs there.

I always found it a bit complicated to read documentation on CPAN. If the author does not give a lot of love to the documentation it's even complicate to browse through all the docs of each module, since there is no auto-generated TOC over the complete distribution (only on inside each modules doc).

But there are even more issues.
See how the documentation of EBook::MOBI looks like on my screen (1920x1080):

This is what you see first. It is a horrible layout, isn't it? You have so much unused space and the TOC is so big that you don't see what you are probably most interested in... a small description and the example in the SYNOPSIS.

This post also serves as a reminder to self, to always, Always, ALWAYS check The CPAN first in the future.

Existing module on CPAN (which I failed to discover in time): WWW::PAUSE::CleanUpHomeDir

My solution (UserJS): pause-delete_files-select_all_older_releases_files.user.js

Ref: perlmonks thread

Hi All
How i can access a website with the help of Perl
- I am able to open the website and can enter the username and password and then log in into it
- After loginned i have to select a value from a drop down box(How Can i do that?)

So, like my entry on YAPC::Asia Tokyo 2011 last year, I thought I'd give you guys a very brief tour of what it was like this year. Before I start, you can find the full set of photos here, and videos will be uploaded here.

Find my signature in the Google NY office, tell me where it is (you're not supposed to take pictures), and I'll send you a set of my books. It's not hidden, but it's not out of place either.

You don't have to work for Google to make good on this. The same technical sourced that gave me the tour can do the same for you. Ask for for the referral and I'll tell you who you have to talk to. If you were at dinner with me and NY.pm at Wildwood, you've already met him.

Google isn't known as a big Perl user, but Google isn't really looking for skills, unlike most companies I visit. They want people who know how things work, and everything after that is just tools.

Maybe I should send Google a set of books too. In there several walls of tech books, they have the right Perl titles, just in older editions.

Do you mark favorite distributions on metacpan.org? Do you want to be able to do:

% cpanm -n Task::BeLike::YOURCPANID::Favorited

to install all your favorite modules in one go?

If yes, install Dist::Create::TaskBeLikeFavorited to create your task distribution, then type:

% create-task-belike-favorited-dist YOURCPANID
% cd Task-BeLike-YOURCPANID-Favorited
% dzil release

You'll probably want to tweak the generated dist.ini prior to dzil release.

An example distribution created by this tool is Task-BeLike-SHARYANTO-Favorited.

You'll also want to run:

% update-task-belike-favorited-dist
% dzil release

from time to time, to update your task, if you add/remove favorites.

Have fun.

Please note: the following was done as an exercise in intellectual curiosity and not in any way an example of a real optimization. Any comments about "premature optimization" will be downvoted as soon as we get a voting system ;)

We're deep in the heart of micro-optimizing some extremely performance-intensive code when I stumbled across this:

if ( $number == -1 ) {
    # do something
}

Clearly a numeric comparison isn't expensive and I managed to find a few areas where we could improve some performance, but out of curiosity, I decided to benchmark $number == -1. The -1 is returned if a function failed (because throwing an exception would be far too expensive here) and we test for that. In reality, we only care if the number is less than 0. I was mildly curious to know if I could get a tiny performance increase in bit comparison (again, this was curiosity only. If I have to get this deep in optimization, I have more serious issues than this).

[ crossposted from its original blog ]

Welcome to Perl 5 Porters Weekly, a summary of the email traffic on the perl5-porters email list. Normally, I'd have a dusty thread and some "witty" banter here, but I'm just running too far behind for that this week.

Topics this week include:

• Perl 5.17.4 is now available
• Parrot 4.8.0 "Spix's Macaw" Released!
• WANTED: "whole program" benchmarks
• Changing the Perl error message when a module is not found
• Subroutine signatures on the blog
• Why ugly Perl is a guide for optimizing Perl

Hi

If you're using AT&T's Graphviz and you're interested in finding fixed length paths thru your graphs, there's a new module to help.

You'll need Marpa, and GraphViz2, and GraphViz2::Marpa. These will be installed as pre-reqs.

Then all you need is GraphViz2::Marpa::PathUtils, after it hits CPAN.

You can start reading the docs here.

Cheers