MRE3 Reviewed on Slashdot

The new edition of my book Mastering Regular Expressions was reviewed on Slashdot today, where the reviewer generously granted me a rating of “11 out of 10.” In looking over the comments people left during the course of the day, I appreciated the kind words many chimed in with about the book.

I found it amazing, though, even by Slashdot standards, the amount of ignorance displayed in a few of the comments. Here's an excerpt from such a comment:

It is true that some extensions, especially those found in perl, push the regular expression into Context-free or Context-sensitive territory when used correctly, but generally speaking, you're really asking for one disaster of a Regular Expression. You're better off using a parser.

Now, if you know much of anything at all about modern-day scripting languages and their regular-expression implementations, you know immediately how outlandishly stupid the comment is.

The problem with comments like this is that if the reader doesn't already understand the situation, they'll not necessarily know that the comment is ignorance incarnate, and perhaps be lured in by the fancy mathematical words like “context-free” and actually think that the comment has some validity.

I'll be the first to warn that regular expressions are just one tool and that they are certainly not the hammer for every programming nail, but comments like this are basically saying that only pure DFA implementations circa 1979 are worth using, and the use of any features added since then is bad. Geez, even before I wrote my book, few would have espoused such an opinion, but it's lamentable to see it now 10 years after the first edition, in a discussion of the new edition, by someone who's clearly never read either but even more clearly needs to. (One of the reasons I wrote the book in the first place was to try to clear up this ignorance-borne foreboding of regular-expression technology that one occationally sees.)

To my family and regular readers more used to posts about Japan, Anthony, or with pretty photos, who may not understand anything of this post past the first paragraph, I offer this cute picture of a just-turned-one-year-old Anthony sweeping the floor:

The trick will be getting him to do it when he's 13!

All 5 comments so far, oldest first...

Speaking as the reviewer, I assure you that your book earned that 11 out of 10. There was no being generous; that’s not my style. 🙂

And thanks for your explanation of your image framing. After I left my initial comment on your site asking about it, I did some experimenting of my own and it’s interesting to see some of the similarities and differences between how we did it. I love your landscape pictures. As a landscape photographer myself (the mid-West of America), it’s lovely to see someone elses view of a different land.


— comment by Simon P. Chappell on September 15th, 2006 at 9:15am JST (17 years, 5 months ago) comment permalink

Hahahah, I’m not a “landscape photographer” — I take a carpet-bombing approach to photography: take a lot of pictures, and cross fingers 🙂

In any case, thanks indeed for the kind review(!)


— comment by Jeffrey Friedl on September 15th, 2006 at 10:50am JST (17 years, 5 months ago) comment permalink

> some extensions, especially those found in perl, push the regular
> expression into Context-free or Context-sensitive territory

Although I don’t believe that and I used to be an all-out hater of Perl, the language-of-the-worst-readability, I envy Perl regexp only in that you can use group match, written as $n in Java regexp, in other expressions freely.

Oh, however, if one wasn’t a professional Perl programmer for a long time, he/she could never write MRE or its equivalent. FYR, I was quite a feeble regexp user via tools like sed, awk and vim while he was writing Yahoo Finance CGIs. My real earnest regexp prgramming just begun with the advent of java.util.regexp. And of course MRE helped me a lot in that regexp baptism. I’d like to continue reading this blog as a valuable extension of the learning.

BTW, I used to feel the Japanese translation of the term regular expression, ‘seiki hyogen’, as awkward and weird at best. But sadly, I do not have better alternative(s).

— comment by Hiroshi Iwatani on September 15th, 2006 at 12:57pm JST (17 years, 5 months ago) comment permalink

A note about the previous commenter: Hiroshi Iwatani is himself an author of several books on Java, and a Japanese translator of
various English-langauge comp-sci books. Judging by the home page for his latest book, he’s a very conscientious author with extras and a detailed errata.

Hiroshi, I appreciate your comments. I can also understand why 正規表現 (seiki hyougen — “regular expressions”) feels awkward…. it’s because the first part, 正規 (“regular”), has the same pronucuation as 性器 (non-Japanese can follow the link to see its meaning 🙂 )


— comment by Jeffrey Friedl on September 15th, 2006 at 4:03pm JST (17 years, 5 months ago) comment permalink

And how does one define Landscape Photographer? One who photographs landscapes. And if anyone has ever bought one of your pictures, then you are a professional photographer. Easy!

And, as Ken Rockwell ( says: take lots of photographs and never show anyone the bad ones. That’s what I do! 🙂

I have the first phase of my photography site up and available for viewing now. Check out You’ll also see that I made wallpapers of all my stock pictures after being inspired by your Simple Japanese Garden picture (which I have set as my wallpaper on my work computer now. 🙂


— comment by Simon P. Chappell on September 16th, 2006 at 12:07am JST (17 years, 5 months ago) comment permalink
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