Hi all, I have just met a strange problem (it might have already been answered, but I can't find the it) while using camlp4 to generate a polymorphic type like:
type t = [ `A of int * int | `B of string ] error msg "The present constructor A has a conjunctive type" is thrown by the compiler. I followed the ocaml source code, found in ocaml-3.10.2/typing/typetexp.ml Line 290, it does the following check in add_field function: if List.length stl > 1 || c && stl <> [] then raise(Error(styp.ptyp_loc, Present_has_conjunction l)); Sorry, I can't fully understand the source code, but it seems we can only define a polymorphic variant with only one additional type declaration, like `A of int or `A of (int * int) rather than `A of int * int It looks wired, as we can directly define type t = [ `A of int * int | `B of string ] in toploop or a *.ml file. Or I have some mis-understanding in this part. Thanks for any help. Best regards, Conglun _______________________________________________ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs