On Understanding Data Abstraction, Revisited -- Cook

You should read the paper below, and then we'll talk about it. Bring your thoughts, questions, etc, and maybe we'll come to a consensus about what exactly it is we read. It's likely that this will take place at Meetup HQ, as that's the easiest place for me to acquire, but I'll post an update confirming or denying it. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Abstract: In 1985 Luca Cardelli and Peter Wegner, my advisor, pub- lished an ACM Computing Surveys paper called “On un- derstanding types, data abstraction, and polymorphism�. Their work kicked off a flood of research on semantics and type theory for object-oriented programming, which contin- ues to this day. Despite 25 years of research, there is still widespread confusion about the two forms of data abstrac- tion, abstract data types and objects. This essay attempts to explain the differences and also why the differences matter. http://www.cs.utexas.edu/~wcook/Drafts/2009/essay.pdf