-
Simon Peyton Jones authored
---------------------------- Re-do kind inference (again) ---------------------------- [WARNING: interface file binary representation has (as usual) changed slightly; recompile your libraries!] Inspired by the lambda-cube, for some time GHC has used type Kind = Type That is, kinds were represented by the same data type as types. But GHC also supports unboxed types and unboxed tuples, and these complicate the kind system by requiring a sub-kind relationship. Notably, an unboxed tuple is acceptable as the *result* of a function but not as an *argument*. So we have the following setup: ? / \ / \ ?? (#) / \ * # where * [LiftedTypeKind] means a lifted type # [UnliftedTypeKind] means an unlifted type (#) [UbxTupleKind] means unboxed tuple ?? [ArgTypeKind] is the lub of *,# ? [OpenTypeKind] means any type at all In particular: error :: forall a:?. String -> a (->) :: ?? -...
f714e6b6