Design Patterns in Moose

These days, design patterns are everywhere. And why not? Exposure is what shapes raw developer-material into greatness! And what better way to get exposure than through condensed experience in the form of Design Patterns - well-formulated problems and the pragmatic programmatic patterns that solve them!

Mind you, Design Patterns are a double-edged sword. The strength is also the weakness - too many patterns and one faces the classic problem known as over-fitting in the predictive modeling community, to wit, one becomes useless at doing anything that differs from what one has seen before.

The trick to design patterns is building this castle on a solid foundation of systems engineering. That is, knowledge of software systems and their interacting components. Practical knowledge of software systems. One has really got to be at a point, like Beethoven poised to write the 9th symphony, where all past work seems vaguely dissatisfying. Yes, work got done, but it could have been done better! Perhaps, the people maintaining that code-base you contributed to are complaining. Or there are faint but audible murmurs about how they wish they could just throw away that code-base and start from scratch.

You have got to base knowledge of Design Patterns on experience.

Thus forewarned, pardner, let me now roll-out before you my plan. You see, Design Patterns have been popularized in the Java world by a nifty book called "Head First Design Patterns" that features a hot chick on the cover at a flattering angle. And, about the same time, the Perl world is abuzz with Moose - a swanky post-modern object-oriented framework. Need I say more?

What this is about is implementing the Design Patterns - fully a Baker's dozen of them - in Moose-Perl. Now whaddya say to that?

The idea is not a one-one mapping between concepts in the Java and Moose worlds, but to demonstrate the effectiveness of the Moose framework. Or possibly the lack thereof, for this blog is objective. See, there is a lot of talk lately of how Perl is falling behind newer entrants like Python and Ruby. There is talk of how companies with an eagle eye on the bottom-line are moving away from Perl. And how, very soon, the only programmers in the Perl world are likely to be legacy coders.

That disturbs me. Because I really like Perl. Deep down, I feel a sense of well-being coding in Perl that I don't feel elsewhere. It is like Perl is my native tongue, aligned with my thought patterns. When I code in Perl, code seems to flow out of my fingers from the thoughts abuzz in my mind.

And that is fun! Fun that I would like to share with others in the world. Anyone have a pic of Larry's daughter? I hear she is hot! Just kidding folks, testing to see that you are still with me.

This series isn't going to be spoon-feeding. Neither is it an introduction to object-oriented programming. Where it seems appropriate, I shall point out certain object-oriented features to rave about. Or rant at abuse of the principles underlying these features. The idea, as always with this blog, is that you - the intelligent, handsome, sexy reader - try out stuff. And have fun doing it. I'll give you enough to keep you going.

Watch out for the Moose!

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All code in this series may be downloaded from:
http://sites.google.com/site/sanjaybhatikar/codeunquote/designpatterns-1