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)

Modifying regexes with adverbs

Adverbs are regex modifiers. They are colon-prefix letters that change the behavior of regexes.

Adverbs exist in two forms—short and long—and appear in front of a regex, for example:

say 'OK' if 'ABCD' ~~ m:i/ abcd /;

Notice, that when an adverb is applied to the whole regex as in this example, m or rx is needed. Alternatively, an adverb can be put inside the regex. In this case, it starts its action from the position where it appeared. This is demonstrated in the examples in the next section about the :i adverb.

The following table lists all the adverbs:

Short form Long form Description
:i :ignorecase Match letters are case-insensitive
:s :sigspace Whitespacess are significant
:p(N) :pos(N) Start at position N
:g :global Match globally
:c :continue Continue after the previous match
:r :ratchet Disable...