• Simon Peyton Jones's avatar
    Support polymorphic kind recursion · c9117200
    Simon Peyton Jones authored
    This is (I hope) the last major patch for kind polymorphism.
    The big new feature is polymorphic kind recursion when you
    supply a complete kind signature for a type constructor.
    (I've documented it in the user manual too.)
    This fixes Trac #6137, #6093, #6049.
    The patch also makes type/data families less polymorphic by default.
       data family T a
    now defaults to T :: * -> *
    If you want T :: forall k. k -> *, use
       data family T (a :: k)
    This defaulting to * is done whenever there is a
    "complete, user-specified kind signature", something that is
    carefully defined in the user manual.
TcRnTypes.lhs 55.7 KB