Array Int (IORef (Int -> Float)) The first "Int" is the type of the array's index, which in C is always "int" and hence not specified. (As you note yourself,

Array Int (IORef (Int -> Float)) The first "Int" is the type of the array's index, which in C is always "int" and hence not specified. (As you note yourself, pointers, or even just arrays, are not very much of a Haskell concept, but I still think this is pretty readable and very obviously parseable if you know the involved types "Array i e" and "IORef a".)