WASP.NET

Questa sera ho partecipato alla chat sui Design Patterns organizzata da Emanuele. E' stata molto interessante, un esperimento da ripetere, la discussione era piuttosto fluida e le opinioni dei partecipanti molto interessanti.

Ne approfitto per rettificare una mia affermazione su Vlissides e il pattern Singleton: non era lui a proporne la rimozione dal liblro della GoF, o quantomeno non ho più trovato sue affermazioni in merito nonostante ci siano suoi scritti critici in merito, la mia convinzione veniva da un'errata associazione di idee con un vecchio post di Fowler sul suo blog (commento all'OOPSLA2004, http://www.martinfowler.com/bliki/OOPSLA2004.html), che riporto, dal quale si evince che Singleton è in generale considerato da molti come un pattern da rimuovere tra la lista di quelli "buoni":

Before the beginning of the conference proper I attended a workshop on reappraising the GoF book, ten years after it came out. ...

We did a number of discussions around the what next theme, perhaps the most interesting one to report was an exercise in considering some to 'vote off the island'. People voted on the patterns to indicate which ones they felt needed deletion in the current form.

Four patterns were voted off. Factory Method (due to the confusion over what it means - the pattern is different to the more common usage of the term), Bridge, Flyweight, and Interpreter. Two patterns, Singleton and Chain of Responsibility, were split decisions.

I found the votes and discussions interesting. Of course it's hard to really consider this without looking at alternatives. I was surprised that Singleton got away with a split decision, considering how unpopular it's become amongst my friends. Most of the others were voted off because people felt they were sufficiently uncommon and that other patterns would probably take their place, sadly we didn't have time to consider new members.

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