nil is weird in Go, and in most languages with an equivalent concept. It's a "hole in the type system" In Smalltalk, nil just contains the sole instance of the

nil is weird in Go, and in most languages with an equivalent concept. It's a "hole in the type system" In Smalltalk, nil just contains the sole instance of the UndefinedObject class. It's not a hole in the type system. Instead, it becomes a paradox in the inheritance system, because it's used as a superclass. Here's a WAT. Smalltalk is actually strongly typed. It's just that everything has the same type of Object. (The type system has no holes. However, it's the size of a thimble!)