Oh, I understand why null was needed (backwards compatibility, like you said), and I'm no language designer, so I don't know what I would have done instead. Maybe mark pieces of code that must interact with Java code with "unsafe" blocks, outside of which no nulls can escape?
unsafe {
...
}
Don't know if this would work. I'm just disappointed because this slightly breaks the Option type, that's all.
> I'm just disappointed because this slightly breaks the Option type, that's all.
I have never ever seen this happening.
The complaint feels a lot like "well, someone could use reflection and change the cached values of Integer, why don't you check that every time something returns an Integer?" to me.
null is the sad fact of running on the JVM, but pretending that it doesn't exist works 99.9999% of the time in Scala.
I know I'm beginning to sound like a broken record, but "I have never seen this happening" is a poor argument when discussing type systems. Please realize that "I've never seen a type bug like this happen" is exactly what proponents of dynamic typing will say when dismissing the burden of static typing: "I've never seen a bug caused by incorrect types. It sounds nice in theory and in your contrived examples, but in practice type errors never happen to me, therefore I don't want a type system that gets in the way."
The fact is that type system should NOT allow an Option val to be null. That's what type systems are there for. If a Scala programmer coming from a Java background wants to use null in Scala programs, the compiler will happily allow it. This is awful practice in Scala, of course, but it's allowed without warning. I've seen this happen with amateur Scala devs (and I'm ready to admit I'm an amateur with Scala too, I don't want to sound condescending).
Your remark that "null is the sad fact of running on the JVM" was what I was saying all along. Am I allowed to express disappointment that Scala's type system is compromised because of this fact?
> Your remark that "null is the sad fact of running on the JVM" was what I was saying all along. Am I allowed to express disappointment that Scala's type system is compromised because of this fact?
What I'm saying is that you are barking up the wrong tree. You need to go to Oracle and complain there if you are unhappy about nulls.
