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)

Live supplies

Live supplies generate data regardless of the number of taps. Unlike on-demand supplies, if there are no taps open, emitted data is still generated and it simply disappears. As soon as the tap is open, it starts receiving data from that moment; all the history is lost.

To create a live supplier, call a constructor of the Supplier class. A tap must be connected to the supply, returned by the Supply factory method. This is all shown in the following example:

my $supplier = Supplier.new;

$supplier.Supply.tap({
say $_;
});

$supplier.emit($_)
for 'a'..'e';

You may be a bit confused by the presence of both the Supply and Supplier classes. The Supplier class is a factory to generate live supplies.

Let us see how live supply streams data and what happens when no taps are open. In the program below, a live supply generates data in a separate thread created...