Mastering Regular Expressions [Anglais] [Broché]

I am a Perl/CGI programmer, and I had considered myself good at RegExp even before I read this book. Most of the things I knew were from Programming Perl, 3rd edition (chapter 5, Pattern Matching). But I still decided to give Jeffrey a chance since I was having some trouble with my Parse::Syntax module, which is designed to parsing *any* programming language and highlighting the syntax accordingly (provided it has a syntax/grammer file written for the specific language). The accuracy of the parser (and more importantly the speed) does depend on well crafted regular expressions.

As I started reading the book, I couldn't stop. I took it to my school's cafeteria with me and no one could make me leave untill I finished the whole book. I was excited. I was pleased! Here is the outline of tha chapters:

Chapter 1 and 2 introduce you to regular expressions and give some basic regex examples. Mail utility and date matching is two of them.

Chapter 3 mostly talks about conventions that all the regex tools follow and their differences.

Chapter 4 deals with Traditional NFA, POSIX NFA and DFA regex engines and their pros and cons. What you'll like the most is the details provided by the author on each and every single example. He also uses a lot of step-by-step illustrations to take you deeper into the regex engine itself and see/feel how it works. He shows the point of backtrackings and provides awesome benchmarks. He uses such examples of matching a quote, allowing escaped quotes inside the pattern, matching C-style comments, IP addresses and many more.

Chapter 5 deals with writing efficient regular expressions for NFA engines. It also re-vists some of the examples provided in the previous chapter and fine-tunes them.

Chapter 6 and 7 deals with Tool-Language specific features of Regex engines. Chapter 6 is dedicated to Awk, Tcl and GNU Emacs, whereas chapter 7 is entirely dedicated to Perl, good over 100 pages of Perlism.

It's true that there're features that Perl 5.6 offers when it comes to regex that didn't exist at the time this book went to press, (lookbehinds, for example). But this no way makes this book dated. Just take my word for it. Jeffrey put together a great masterpiece that will not die for many years, no matter how fast the technology tends to enhance
Haven't read anything more exciting than this for many years.

Regular expressions are for everyone. They are simple to write and can be close to impossible to read and even unimaginably harder to understand. But reading comes after you can craft one.

And this art of crafting RE is explained in astonishing detail and analysis in this book. Reader is carefully guided through basics, differences and common and uncommon pitfalls. Some of the parts are definitely not for the faint hearted! And this is especially true for parts that cover Perl RE. While main topic is Perl RE engine, a deep-enough travel through different RE dialects is made to help RE-crafting in almost any tool that supports REs.

I've used the methods described in the book in tools as different as MS VC++, various editors, search engines and programming (Perl, PHP, C++, ...). The ability to use RE usually impressed people to the point they were sure I am using some incredible magic.

But I must say that the most useful feature delivered in this book was ability to PARSE, UNDERSTAND and FIX a (slow, broken, strange acting) RE. This can be slowly absorbed by reader's (open) mind while carefully reading the book. The difference between meant/written can be as extreme as it can get in RE. I can (proudly) say I've been able to fix several complex REs, by simply (one could say blindly) following the rules laid in the book.

My opinion is thath without this book real understanding of RE is almost impossible. I recommended it all of those who use programs that support (any form) of RE engine. It will help them solve some (hard) problems incredibly fast!

Regular expressions are such a powerful concept, but some of that power would be easy to miss if not guided correctly through the topic. Jeffrey Freidl does a great job of making a potentially very dry subject interesting, even while getting very involved in all the complexities that are inherent in such a powerful abstraction. He also does a good job of presenting both the general topic of regular expressions and the specific characteristics of the various tools available to process them.

This is a book that you will come back to many times. I actually read it as a precursor to learning Perl several years ago. Then just recently I revisited it while taking a class on compiler construction and found that it still had useful insights for me. If you're a committed programmer, this book should be on your shelf.

Also, the criticisms I've read in reviews here are pretty misguided. It is "chatty", because the author has a genuine enthusiasm for his subject. It is also not a "teach yourself regular expressions in 24 hours" kind of book. There are actually lots of cookbook style examples, but the main point of the book is to give you a solid enough understanding of the general topic that you don't need examples to craft your regexes. In this case, little patience as a reader will be much rewarded.