null [re: spec#]

[bearophile]

Nick Sabalausky:

> Also, I'm curious what you mean by "collection initialization" and 
> "simplified typestate management".

Collections, like an array, need a temporary transient state where they may contain nulls too.

The simple typestate management means that if you want to implement nonnull types well, the type system need to see the type of a variable as nullable in a point of the code, and nonnull later. The presence of an if statement or assert or cast needs to change the state of the type of the variable.

I have explained a bit both things several times in posts. The problem with collections and the typestate needs are explained in the original little tutorial about Spec# in my first post of this thread.

Bye,
bearophile