Book Image

Perl 6 Deep Dive

By : Andrew Shitov
Book Image

Perl 6 Deep Dive

By: Andrew Shitov

Overview of this book

Perl is a family of high-level, general-purpose, interpreted, dynamic programming languages consisting of Perl 5 and Perl 6. Perl 6 helps developers write concise and declarative code that is easy to maintain. This book is an end-to-end guide that will help non-Perl developers get to grips with the language and use it to solve real-world problems. Beginning with a brief introduction to Perl 6, the first module in the book will teach you how to write and execute basic programs. The second module delves into language constructs, where you will learn about the built-in data types, variables, operators, modules, subroutines, and so on available in Perl 6. Here the book also delves deeply into data manipulation (for example, strings and text files) and you will learn how to create safe and correct Perl 6 modules. You will learn to create software in Perl by following the Object Oriented Paradigm. The final module explains in detail the incredible concurrency support provided by Perl 6. Here you will also learn about regexes, functional programming, and reactive programming in Perl 6. By the end of the book, with the help of a number of examples that you can follow and immediately run, modify, and use in practice, you will be fully conversant with the benefits of Perl 6.
Table of Contents (15 chapters)

Introspection

Perl 6 modules contain a mechanism that allows you to get information about the content of the module. Obtaining this meta-information is called introspection.

Take the Math.pm modules from the previous section, More on is export, as an example. This is how we can list all the methods that are exported by that module:

use Math;

say Math::EXPORT::.keys;

This refers to the default EXPORT sub, which the compiler generated for us. The sub returns an object of the EXPORT type that implements the Perl6::Metamodel::PackageHOW interface. We'll not go deep into that theory and will limit ourselves to calling a useful method keys that gives us a list of the tags available in the module:

(plusminus muldiv ALL)

Having the list of tags, we can iterate over them to get the list of subroutines that belong to them:

use Math;

say Math::EXPORT::plusminus::.keys;
say Math::EXPORT...