A hastily-assembled review of Perl advent calendars for 2019

Work greatly interfered with this, so I'm afraid this presentation is a bit less polished than I would like. My apologies.

Overview

• the Perl Advent Calendar 2019
• The Raku Advent Calendar 2019

There was another semi-Perl-related advent calendar as well:

• A Language A Day, Andrew Shitov’s 2019 Advent Calendar

Perl Advent Calendar

The Perl 5 Advent Calendar, erst managed by Jerrad Pierce, this year again run by Mark Fowler.

the Perl Advent Calendar 2019

My highlights

• Day 7: Show Me Mo'; the Mo module
• Day 12: Now With Added Interactivity; GUIDeFATE
• Day 18: Core Strength; Module::CoreList Module dependency graphs
• Day 21: Test2: Test Harder (but easier); Test2::V0

Mo

Day 7: Show Me Mo'

Last year, the Advent calendar discussed Mu, which is a shortcut for importing Moo and MooX::ShortHas.

This year, in the line of “Moose still hasn't taken over the world”, it offers Mo. Mo is part of the great continuum of Moose modules: M, Mo, Moo, Moos, and of course Moose (see also MooseX and MooseY).

Mo gives you very basic new, extends, and has keywords. It has some optional features provided by helper modules.

One nice thing is that you can use Mo::Inline to create a custom base module with your own combination of features.

In the design documents, there is a fun line: “Mo.pm and its feature modules are golfed, compressed and unreadable by mere mortals.”

Another cool bit of code is in the article at the bottom, where you can inline Mo into any file.

GUIDeFATE

Day 12: Now With Added Interactivity

“GUIDeFATE” is short for “GUI Design From A Text Editor”.

The idea is that you can easily create a (basic) GUI by describing the interface using ASCII-style art.

A bunch of example programs from the GUIDeFATE wiki.

Module dependency graphs

Day 18: Core Strength

Day 18 is interesting to me not as much for the module highlighted (Module::CoreList), but for the link to the module dependency graphs.

For instance:

• Moo
• Moose
• Test::Most
• Email::Stuffer
• Plack

Hours* of fun!

* well, minutes of fun at least…

Test2::V0

Day 21: Test2: Test Harder (but easier)

I intend to prepare an entire talk about this, but I find Test2 to be a useful upgrade on the more classic Test:: modules.

I've written a fairly large test suite using Test2, so here are some files we can look around…

• Countries.t (Countries.pm)
• EnvObject.t (EnvObject.pm)
• Logger/log.t (Logger.pm)
• POCatalog.t (POCatalog.pm)
• Rotator.t (Rotator.pm)
• Rules/new.t (Rules.pm)
• Translator.t (Translator.pm)

There is some interesting documentation, some YouTube videos of talks about the Test2 suite from 2017, 2018, and 2019. Also, there is documentation and a video about yath.

Mini-themes

There were several thematic groupings in the Advent calendar this year:

• Passwords and authentication:
  • Day 1: J1ngle? No...zxcvbn; Data::Password::zxcvbn
  • Day 2: Have Elf Been Pwned?; WebService::HIBP
  • Day 3: Two Factor Elfication; Authen::OATH
• Better interfaces:
  • Day 9: Command Line Browser Apps; Net::EmptyPort Browser::Open
  • Day 11: Now With Added Interactivity; Mojo::Transaction::Websocket QuickBrowserGUI
  • Day 12: Now With Added Interactivity; GUIDeFATE
• Amazon AWS:
  • Day 15: Suddenly Serverless; AWS::Lambda::Quick
  • Day 16: Paws to Plan What Todo; Paws
  • Day 17: Taking the Sleigh to a CloudFront
  • (Day 18, presented as useful with regard to AWS: Core Strength; Module::CoreList Module dependency graphs)
• Test2:
  • Day 21: Test2: Test Harder (but easier); Test2::V0
  • Day 22: Comparing More
  • Day 23: Testing our Impatience; yath
• Image creation:
  • Day 14: Animated GIFs; GD
  • Day 24: We Wish You a Meme Christmas; Imager
• Integration and tools:
  • Day 4: Going for Perl; FFI::Platypus
  • Day 5: Christmas Lights
  • Day 6: The Weather Outside Is Frightful; DarkSky API DarkSky::API
  • Day 20: Controlling your Terminal with Perl; iTerm 2

Everything

Raku Advent Calendar

The Raku Advent Calendar 2019

My highlights

• Day 4: Not tripping over tripcodes
• Day 10: A Teaser
• Day 19: Functional Programming with Raku
• Day 24: The Grinch of Raku, Part 2: Hold Your Horses

Creating tripcodes in Raku

Day 4: Not tripping over tripcodes

A tripcode (also here) is a hashed password, constructed in a particular way, which comes to us from the anonymous imageboards (4chan, 8chan, etc.).

I like this because it does a complex string transform, but explains the various parts well. It also shows some nice features of Raku.

A quick optimization tip

Day 10: A Teaser

The article is an extract from an upcoming book (“Migrating Perl to Raku”). This particular snippet discusses a surprising fact; to wit, accessing object accessors is faster than accessing hash keys in Raku.

It also shows a particular idiom from Raku for determining how quickly something is executing:

say now - INIT now;

Functional Programming

Day 19: Functional Programming with Raku

In response to a video (Functional Programming in 40 Minutes), the author explores the three “core concepts” of functional programming in Raku:

• Pure functions (including things like function composition (infix ∘) and currying)
• Immutable data structures (maps, lists, sets, bags)
• Bridging systems (an underdeveloped section of the Advent article, but linking to channels, supplies, react blocks)

“Rakuf*ck”

Day 24: The Grinch of Raku, Part 2: Hold Your Horses

There is a tool called JSF*ck, which is similar in spirit to Acme::Bleach (and of course Brainf*ck), and which uses some features of Javascript to implement any program using just six characters ([,],(,),!,+).

This article walks through translating the JSF*ck idiom to the Raku language, creating something similar. The list of used characters is not quite as compact, but it's still perfectly unreadable.

Everything

Questions?

Fin