Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Perl 6 Deep Dive

You're reading from   Perl 6 Deep Dive Data manipulation, concurrency, functional programming, and more

Arrow left icon
Product type Paperback
Published in Sep 2017
Publisher Packt
ISBN-13 9781787282049
Length 402 pages
Edition 1st Edition
Languages
Arrow right icon
Author (1):
Arrow left icon
Andrew Shitov Andrew Shitov
Author Profile Icon Andrew Shitov
Andrew Shitov
Arrow right icon
View More author details
Toc

Table of Contents (15) Chapters Close

1. What is Perl 6? FREE CHAPTER 2. Writing Code 3. Working with Variables and Built-in Data Types 4. Working with Operators 5. Control Flow 6. Subroutines 7. Modules 8. Object-Oriented Programming 9. Input and Output 10. Working with Exceptions 11. Regexes 12. Grammars 13. Concurrent Programming 14. Functional Programming 15. Reactive Programming

Using the actions class

The more complex a grammar becomes, the more complex the actions. Almost every rule or token in our current grammar has an action. Even if most of the actions are just one or two lines of code, the fact that the Perl 6 code is mixed with the grammar language makes reading the code difficult. Formatting the code also becomes a difficult task, as you need to add more spaces to indent the code properly. In this section, we will see what Perl 6 offers to tackle this issue.

All actions may be moved to a separate class. Thus, the complete grammar contains a grammar itself and an actions class. Correspondence between the grammar rules and tokens and the actions is achieved by simply giving the same names to the methods of the action class. Let us convert our grammar to use the split approach.

First of all, create a class for actions and pass it to the parser:

...
lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at R$50/month. Cancel anytime