Preface

It was all Nathan Torkington's fault. Our Antipodean programmer, editor, and O'Reilly conference supremo friend asked me to update the original Advanced Perl Programming way back in 2002.

The Perl world had changed drastically in the five years since the publication of the first edition, and it continues to change. Particularly, we've seen a shift away from techniques and toward resourcesfrom doing things yourself with Perl to using what other people have done with Perl. In essence, advanced Perl programming has become more a matter of knowing where to find what you need on the CPAN,^[*] rather than a matter of knowing what to do.

^[*] The Comprehensive Perl Archive Network (http://www.cpan.org) is the primary resource for user-contributed Perl code.

Perl changed in other ways, too: the announcement of Perl 6 in 2000 ironically caused a renewed interest in Perl 5, with people stretching Perl in new and interesting directions to implement some of the ideas and blue-skies thinking about Perl 6. Contrary to what we all thought back then, far from killing off Perl 5, Perl 6's development has made it stronger and ensured it will be around longer.

So it was in this context that it made sense to update Advanced Perl Programming to reflect the changes in Perl and in the CPAN. We also wanted the new edition to be more in the spirit of Perlto focus on how to achieve practical tasks with a minimum of fuss. This is why we put together chapters on parsing techniques, on dealing with natural language documents, on testing your code, and so on.

But this book is just a beginning; however tempting it was to try to get down everything I ever wanted to say about Perl, it just wasn't possible. First, because Perl usage covers such a wide spreadon the CPAN, there are ready-made modules for folding DNA sequences, paying bills online, checking the weather, and playing poker. And more are being added every day, faster than any author can keep up. Second, as we've mentioned, because Perl is changing. I don't know what the next big advance in Perl will be; I can only take you through some of the more important techniques and resources available at the moment.

Hopefully, though, at the end of this book you'll have a good idea of how to use what's available, how you can save yourself time and effort by using Perl and the Perl resources available to get your job done, and how you can be ready to use and integrate whatever developments come down the line.

In the words of Larry Wall, may you do good magic with Perl!