We discovered that GHC and GHCi (7.4.1) accept promoted types without specifying language extensions (and even when specifying -XHaskell98).

For example, promoted lists are accepted:

Prelude> type T = [Int,Char]

Prelude> :i T

type T = (:) * Int ((:) * Char ([] *))

-- Defined at <interactive>:2:6

Also, promoted datatypes:

> data N = Z

> type T = 'Z

I'm guessing you can't use these types anywhere (since they are not kind *), so they won't be very useful, but it seems like this should be disallowed.

Regards,

Sean