Should nullary function *syntax* be shorthand for applying to Unit?

[stylewarning]

If we adopt a convention that

(declare f (Unit -> Foo))

represents something stateful or perhaps allocating in nature (e.g., creating a fresh object like a vector), then maybe it’s nice to have a syntax that is Lispy, like

(f)

which at parse-time is rewritten

(f Unit)

Thoughts?

[stylewarning]

My main qualm is that it can just be confusing, especially if (f) ends up being a type error.

At the same time, (make-vector Unit) is odd to see.

[eliaslfox]

(match e
  ((Some (None)) (error "am I matching on None or calling the function None?"))

[eliaslfox]

Actually that isn't ambitious. Patterns can't contain arbitrary expressions.