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Well for today’s post I am going to continue along with one of the basic building blocks of a good Moose program coercion. We saw in the last post how I started to clean up my interface with coercion and I am going to do that to the next Accessor.pm attribute

has elements  => (
    isa => 'ArrayRef',
    is   => 'rw',
);

[This is a post in my latest long-ass series.  You may want to begin at the beginning.  I do not promise that the next post in the series will be next week.  Just that I will eventually finish it, someday.  Unless I get hit by a bus.

IMPORTANT NOTE!  When I provide you links to code on GitHub, I’m giving you links to particular commits.  This allows me to show you the code as it was at the time the blog post was written and insures that the code references will make sense in the context of this post.  Just be aware that the latest version of the code may be very different.]

Last time I rearranged our UI to be (hopefully) a bit more intuitive.  This time I want to clean up the remainder of those pesky CPAN Testers failures on our way to the next solid release.

FFI::Platypus is interesting. It seems like real FFI module for Perl 5.

FFI is foreign function interface. This is a little slow than XS, but you can call C/C++ library without C code.

I saw some FFI module for perl 5, FFI, or FFI::Raw, but not enough to create C extension flexibly.

FFI::Platypus seems like excelent module because you can call any C/C++ library using its features.

FFI::Platypus/CPAN

I try some example. All work well.

Read this article on Perl6.Party

Welcome to the Perl 6 Hands-On Workshop, or Perl 6 HOW, where instead of learning about a specific feature or technique of Perl 6, we'll be learning to build entire programs or modules.

Knowing a bunch of method calls won't make you a good programmer. In fact, actually writing the code of your program is not where you spend most of your time. There're requirements, design, documentation, tests, usability testing, maintenance, bug fixes, distribution of your code, and more.

This Workshop will cover those areas. But by no means should you accept what you learn as authoritative commandments, but rather as reasoned tips. It's up to you to think about them and decide whether to adopt them.

Project: "Weatherapp"

In this installment of Perl 6 HOW we'll learn how to build an application that talks to a Web service using its API (Application Programming Interface). The app will tell us weather at a location we provide. Sounds simple enough! Let's jump in!

Preparation

So today, to start the new year right, I really am going to have a look at Moose coercion which I have been promissing to do since this post . So to refresh your memory I had created my types role and one type and added it to my accessor like this

has view => (
    is     => 'rw',
    isa    => 'View',
);

So what exactly does coercion do for us? Well as I had illustrated in a early post what I want it to do it take an input hash and then create an object from that hash to save us from typing up such unsightly things as

One of my tasks when I'm not working or writing Perl code is to keep the finances of the Frankfurt Perlmongers e.V. club in order. Part of this is doing the taxes but a more important part is to pay the incoming invoices in time and to keep all the receipts for this in order. As we do most transfers electronically, it was a long-term goal for me to provide the board with an automated monthly account statement.

Docker is quite popular solution to rapidly spin up developers environments. I have been playing with it and it seems fun for me. The other fun thing I found that Sparrow could be a good solution to build up new docker images.

Here is short example of how it could be. A few lines in Dockerfile and you have a GitPrep server up and running as docker container. Whew!

Here is my Dockerfile:

If you're interested into using Travis-CI for your Perl projects, here's a few pointers that you should not miss:

• Graham Knop's article introducing the helpers;
• fREW's article on using it, although the specific setup refers to a previous repository that can still be cloned but it's probably not maintained any more (not reachable from Github's portal, anyway);
• Dave Cross's article with slides.

Too bad that it took me so long to find them out.

Well off track again. So I am not going to do my bit on coercion today after all. If anyone out there was actually downloading my code and running my tests you might see this;

Load of Database/Accessor/DAD/Types.pm failed:
Error=Can't locate Database/Accessor/DAD/Types.pm in @INC (@INC contains: D:\GitHub\DA-blog\lib D:\GitHub\Replay\lib C:/Dwimperl/perl/site/lib C:/Dwimperl/perl/vendor/lib C:/Dwimperl/perl/lib .) at (eval 378) line 2.

Database/Accessor/DAD/Types (Database::Accessor::DAD::Types) may not be an Database Accessor Driver (DAD)!

Currently rakudo.js is at the point where:
node rakudo.js --setting=NULL -e 'use nqp; nqp::say "Hello World"'
works but node rakudo.js -e 'say "Hello World"' doesn't.

What's needed for the later is to get rakudo.js (Rakudo compiled to JavaScript) to compile the setting

The general work-flow for that is:

1. Try to compile the setting with rakudo.js.
2. While rakudo.js is compiling some error appears.
3. I then figure out wheter it's a result of a missing feature or some bug in the js backend.
4. I implement the feature and write tests for it or fix the bug.
5. I then repeat the process.

Lather, rinse, repeat.

Until the setting compiles Rakudo.js is not yet usable by users.
Even getting something very simple like say "Hello World" requires a fair chunk of the setting to work.

The rakudo specific work is done in the js branch of rakudo https://github.com/rakudo/rakudo/tree/js.
Most of the work on the backend itself is done in the master branch in the nqp repo.

I recently wrote about Veure's test suite and today I'll write a bit about how we manage our database. Sadly, this will be a long post because it's a complicated problem and there's a lot to discuss.

When I first started Veure, I used SQLite to prototype, but it's so incredibly limited that I quickly switched to Postgres. It's been a critically important decision, but I want to take a moment to explain why.

All software effectively has four "phases" which amount to:

1. Initialization
2. Input
3. Calculation
4. Output

Note that we could rewrite the above as:

1. Initialization of data
2. Input of data
3. Calculation of data
4. Output of data

Notice a pattern?

Yeah, I thought so. There are all sorts of areas where we could get things wrong in software, but the further down the stack(s) you go, the more care you need to take because the more damaging bugs can be. Data storage is often pretty low in your stack and you don't want to get this wrong. So what happens?

Hey everyone,

Following is the p5p (Perl 5 Porters) mailing list summary for the past week. Enjoy!

Now to get back on track to what I wanted before I made a little Boo-Boo, So in today's post I am going to have a quick look at Moose and its Coercion abilities. One thing about moose Coercion is it works along with Moose Types so you can't have one without the other.
So lets start wit the Accessor.pm 'View' attribute.

Right now we have this

has View => (
    is     => 'rw',
    isa    => 'Object',
); 

Which is fine but there is noting stopping my from entering any type of object in there so lets fix that

Read this article on Perl6.Party and play with code examples right in your browser!

Back in the day, I wrote Perl 5 module Number::Denominal that breaks up a number into "units," say, 3661 becomes '1 hour, 1 minute, and 1 second'. I felt it was the pinnacle of achievement and awesome to boot. Later, I ported that module to Perl 6, and recently I found out that Perl 6 actually has .polymod method built in, which makes half of my cool module entirely useless.

Today, we'll examine what .polymod does and how to use it. And then I'll talk a bit about my reinvented wheel as well.

Denominated

The .polymod method takes a number of divisors and breaks up its invocant into pieces:

While playing with docker I created a simple sparrow plugin to install docker engine on Ubuntu Trusty 14.04 (LTS) - https://sparrowhub.org/info/docker-engine . Please let me know if other platform to support you need! ;))

Much of what I do involves retrieving stuff over the HTTP family of protocols. My go-to solutions are either the APIs of LWP::UserAgent/WWW::Mechanize or the API of AnyEvent::HTTP, depending on whether I want some kind of concurrency or not. Since I found Future as a somewhat nicer way of structuring callback hell a bit differently, I've looked around for a nice implementation of a HTTP client that works with various backends and maybe even without a backend.

Well in my last post I made a little boo-boo. Well a few really. I wanted to get rid of my 'View' class as it was the same as my 'Element' class once I stripped out some parts. Unfortunately I discovered that I have to add in a number of other attributes to my 'Element' class which should never be part of the 'View' class. So I am going to backtrack on taking View out and put it back in.

Now my second boo-boo from my last post, I wanted to have first letter upper case names for my Accessor attributes like this

DISCLAIMER: data theft is a serious crime in many jurisdictions. The author does not condone or encourage anyone to break laws. The information provided here is for educational purposes only.

PART I: Anguish: The Invisible Programming Language

You may be familiar with funky esoteric languages like Ook or even Whitespace. Those are fun and neat, but I've decided to dial up the crazy a notch and make a completely invisible programming language!

I named it Anguish and, based on my quick googling, I may be a lone wolf at this depth of insanity. In this article, I'll describe the language, go over my implementation of its interpreter, and then talk about some security implications that come with invisible code.

The Code

Here's an Anguish program that prints Hello World:

‌⁣‌⁣‍⁣⁣⁡⁢​⁠‌‍⁣⁣‍⁡⁡⁡⁡⁡⁡⁡⁡‌⁠⁡⁡⁡⁡‌⁠⁡⁡⁠⁡⁡⁡⁠⁡⁡⁡⁠⁡​​​​⁢‍⁠⁡⁠⁡⁠⁢⁠⁠⁡‌​‍​⁢‍⁠⁠⁣⁠⁢⁢⁢⁣⁡⁡⁡⁡⁡⁡⁡⁣⁣⁡⁡⁡⁣⁠⁠⁣​⁢⁣​⁣⁡⁡⁡⁣⁢⁢⁢⁢⁢⁢⁣⁢⁢⁢⁢⁢⁢⁢⁢⁣⁠⁠⁡⁣⁠⁡⁡⁣

Here's another one that reads in a 4-character string and prints it back out:

⁠⁠⁠​​​⁣⁠⁣⁠⁣⁠⁣

Sparrow plugins development tutorial in Russian. https://habrahabr.ru/post/300876.

I've been busy, busy, busy. Blogging about Perl is one of those things I always said I would get back to one day.

Well, today is that day.

I'm not going to be a daily poster, but I will put my thoughts and rants up here from time to time.