Monthly Archives: January 2011

More backtracking examples

Backtracking might be costly so one should try to avoid useless backtracking. Perl regx have  special form of parentheses: (?>…). These are called Perl’s “don’t-ever-backtrack-into-me” markers. They will tell the regex engine that the enclosed sub-pattern can safely be skipped over during backtracking. As we know that the re-matching the contents either won’t succeed or, if it… Read More »

Backtracking example1

Let’s say you want to find the word following “foo” in the string “Food is on the foo table.”: #!/usr/bin/perl # Example of backtracking algorithm use 5.006; use strict; use warnings; $_ = “Food is on the foo table.”; if ( /b(foo)s+(w+)/i ) { print “$2 follows $1.n”; } When the match runs, the first… Read More »

Backtracking with Perl Regular expression

Wikipedia says Backtracking is a general algorithm for finding all (or some) solutions to some computational problem, that incrementally builds candidates to the solutions, and abandons each partial candidate c (“backtracks”) as soon as it determines that  cannot possibly be completed to a valid solution. What it meant for Perl: In fact Backtracking mechanism is core functionality of… Read More »

Perl coding tips from expert

[brightcove vid=724203979001&exp3=651017566001&surl=,AAAAGuNzXFE~,qu1BWJRU7c26MMkbB19ukwmFB5ysvYz5&w=300&h=225] Bigthink have many expert talks on Perl by Larry Wall. Enjoy!

Perl 6 book project on github

A Perl 6 book is in development on github. One can try and fork source code. You can catch the authors on #perl6book on For more info like steps to build the book, pl see the README on github. PDF versions of this book can be found at and Enjoy learning  

New Year 2011 Wishes

Dear All, Throughout the Coming Year may your life be filled with little celebration of Happiness…Wishes you a Bright, Happy and Prosperous New Year 2011 Blogged with the Flock Browser