regression/fail/datatype-where-complex.2.sml

   1 (* This should fail because 'a -> 'b is not a type name;
   2  * The Defn does not treat -> as a TyName(2), but rather as a distinct
   3  * sub-class of Type. *)
   4 signature S =
   5    sig
   6       datatype ('a, 'b) t = T of 'a -> 'b
   7    end where type ('a, 'b) t = 'a -> 'b
   8
   9 (* Similarly, this should fail because 'a * 'b is not a type name;
  10  * it is a synonym for {1: 'a, 2: 'b}, which is RowType. *)
  11 signature S =
  12    sig
  13       datatype ('a, 'b) t = T of 'a * 'b
  14    end where type ('a, 'b) t = 'a * 'b
  15
  16 (* Similarly, this should fail because 'a * 'b is not a type name;
  17  * it is a synonym for {1: 'a, 2: 'b}, which is RowType. *)
  18 signature S =
  19    sig
  20       datatype t = T of unit
  21    end where type t = unit
  22
  23 (* On the other hand, The Defn does treat 'ref' and 'int' and other
  24  * primitive types as TyName(k); see Appendix C.  Hence, the following
  25  * should succeed. *)
  26 signature S =
  27    sig
  28       datatype 'a t = T of 'a ref
  29    end where type 'a t = 'a ref
  30 signature S =
  31    sig
  32       datatype t = T of int
  33    end where type t = int