12 July 2013

random tech digression

My view is that you want to avoid shared data structures as much as possible. Systems should be composed of smallish modules that completely hide their internal data structures from everyone else. They should have well-defined 'thin' interfaces that other modules can call to get work done. That's what object-oriented programming is all about--hiding information--not sharing it. I think that hiding information (a la Dave Parnas) is a good idea. It means you can change the data structures, algorithms, and design of any module at will without affecting system correctness, as long as you keep the interface unchanged. Every course on software engineering teaches this. In effect, Linus is saying the past 20 years of work on object-oriented programming is misguided. I don't buy that.

I have to agree with that.