[Peaker]

Then what you have is not "anything". You have an expression problem:

Either each element has some "handler" that does the right thing for that data type.

Or you have a set of cases that each data can be, and you handle them all.

Neither is just "any type". And static types are very suitable to describe either.

[hderms]

The handler being a typeclass in Haskell vs the enumerated cases being pattern matching?

[Peaker]

A type-class or just a callback type, vs pattern-matching, yeah.