As I mentioned before, one of my — very entertaining - projects is a migration of one humangous system from VB6 to VB.NET and WPF. It is quite educational; and one of the things I learn is the evolution of the collective mind of Microsofts’.
During the history of former VB, its designers had been feeling needs for more and more empty types of data. They invented nulls, empties, empty strings, etc. there was a notion of nothing, ismissing, and other thingies I don’t recall now. With .NET someone said: “Why do we need so many empty things?” And they left pretty much Nothing … and DBNull.
After a while, somebody (else?) realized that this was not enough. How do you define an empty date, for instance? And they invented Nullable.
When I observe this evolution, I see Microsoft as a giant ogre who survived a brain surgery. Its memory is stochastic, its vision of the world is eclectic. It forgets its own experience immediately.
Well, thanks to Microsoft we can earn our little money.