ML had "it" in 1973! ... if "it" is even a thing. I would say that it's not, rather implicit nullability is the thing. It's just not something you'd do in a t

ML had "it" in 1973! ... if "it" is even a thing. I would say that it's not, rather implicit nullability is the thing. It's just not something you'd do in a typed language unless you really specifically chose it. That's how Hoare could claim it was his billion dollar mistake. Implicit nullability was a thing he (and subsequent language designers) opted in to.