Moritz Lenz 
Perl 6 Fundamentals 
A Primer with Examples, Projects, and Case Studies

Gain the skills to begin developing Perl 6 applications from the ground up in this hands-on compact book, which includes a foreword from Larry Wall, creator of Perl. You’ll learn enough to get started building with Perl 6, using Perl 6’s gradual typing, handy object orientation features, powerful parsing capabilities, and human-usable concurrency. After a short introduction, each chapter develops a small example project, explaining the Perl 6 features used. When the example is done, you’ll explore another aspect, such as optimizing further for readability or testing the code. 






Along the way you’ll see Perl 6 basics, such as variables and scoping; subroutines; classes and objects; regexes; and code testing. When you’ve mastered the basics,
Perl 6 Fundamentals moves onto more advanced topics to give you a deeper understanding of the language. You’ll learn, amongst other things, how to work with persistent storage, how to generate good error messages, and how to write tricky applications such as a file and directory usage graph and a Unicode search tool.








What You’ll Learn

• Get coding with Perl 6
  


• Work on several hands-on examples and projects
  


• Integrate Python libraries into your Perl 6 programs
  


• Parse INI files using regexes and grammars
  


• Build a date time converter 
  


• Carry out refactoring and other automated tests
  

Who This Book Is For








If you already know one or more programming languages, and want to learn about Perl 6, this book is for you.

Table of Content

1. What is Perl 6?


1.1 Perl 5, the Older Sister


1.2 Library Availability


1.3 Why Should I Use Perl 6?


2. Running Rakudo Perl 6


2.1 Installers


2.2 Docker


2.3 Building from Source


2.4 Testing your Rakudo Star Installation


3. Formatting a Sudoku Puzzle


3.1 Making the Sudoku Playable


3.2 Shortcuts, Constants, and more Shortcuts


3.3 IO and other Tragedies


3.4 Get Creative!


4. Datetime Conversion for the Command Line


4.1 Libraries To The Rescue


4.2 Date Time Formatting


4.3 Looking the Other Way


4.4 Dealing With Time


4.5 Tighten Your Seat Belt


4.6 MAIN magic


4.7 Automatic Tests


4.8 Summary


5. Testing say()


5.1 Summary


6. Silent Cron, a Cron Wrapper


6.1 Running Commands Asynchronously


6.2 Implementing Timeouts


6.3 More on Promises


6.4 Possible Extensions


6.5 Refactoring and Automated Tests


Refactoring


Mocking and Testing


Improving Reliability and Timing


Installing a Module


6.6 Summary


7. Stateful Silent Cron


7.1 Persistent Storage


7.2 Developing the Storage Backend


7.3 Using the Storage Backend


7.4 Room for Expansion


7.5 Summary


8. Review of the Perl 6 Basics


8.1 Variables and Scoping


8.2 Subroutines


8.3 Classes and Objects


8.4 Concurrency


8.5 Outlook


9. Parsing INI files using Regexes and Grammars


9.1 Regex Basics


Character Classes


Quantifiers


Alternatives


9.2 Parsing the INI primitives


9.3 Putting Things Together


9.4 Backtracking


9.5 Grammars


9.6 Extracting Data from the Match


9.7 Generating Good Error Messages


Failure is Normal


Detecting Harmful Failure


Providing Context


Shortcuts for Parsing Matching Pairs


9.8 Write Your Own Grammars


9.9 Summary


10. A File and Directory Usage Graph


10.1 Reading File Sizes


10.2 Generating a Tree Map


10.3 Flame Graphs


10.4 Functional Refactorings


10.5 More Language Support for Functional Programming


10.6 More Improvements


10.7 Explore!


10.8 Summary


11. A Unicode Search Tool


11.1 Code Points, Grapheme Clusters and Bytes


11.2 Numbers


11.3 Other Unicode Properties


11.4 Collation


11.5 Summary


12. Plotting Using Inline::Python and Matplotlib


13. What’s Next?

About the author

Moritz Lenz is a Perl 6 core developer. He has contributed significantly to the official test suite, the Rakudo Perl 6 compiler, and is the initiator of the official Perl 6 documentation project. He has also authored several modules, and runs infrastructure for the Perl 6 community. In his day job, he develops Perl 5 and Python code, and maintains a Continuous Delivery system for his employer.