I go on telling about Saint Perl 2009 conference. This time it is a story about Nikolay Zhuravlev and power of Perl regular expressions. I looked forward to this presentation the worst, and it may be the reason, why it appeared to be the worst disappointment.
I expected an interesting story about recursive regular expressions and how they give Perl the power of context-free grammars. (BTW, ask me how. In fact, we should call them Perl context-free grammar expressions, not Perl regular expressions.) But instead the presentation was about boring benchmark graphs for various randomly — well, almost randomly — assembled regular expressions and without any sane resume. (Though he is totally exonerated by the fact, that he is yet a student.)
Thank Darwin, my perverted imagination saved me from deadly bore, since I had been hypnotized by regular expressions the speaker was showing, that resembled.
/(.*)(.*)\2\1/; # a girl /(.*)(.*)(.*)\3\2\1/; # a mutant girl from Total Recall movie /(.*)(.*)(.*)(.*)\4\3\2\1/; # a girl with a friend /(.*)(.*)(.*)(.*)(.*)\5\4\3\2\1/; # a mutant girl from Total Recall movie with a friend
And so on. Ok, you've got the idea. This is what I meant when I wrote about power of Perl regular expressions.
Now I like regular expressions even more.
P. S. I asked Nikolay Zhuravlev if he had read Mastering Regular Expressions by Jeffrey Friedl — the best book about regular expressions I know of — and he answered that he had tried, but it hadn't appeared mathematically precise enough for him. All issues could be avoided if Nikolay had taken this book more seriously.