🚀 go-pugleaf

I don't have _good_ reference material for SML, so here goes:

If I am creating a module with a signature (see example), how can I  
effectively hide the declaration of a datatype referred to in the sig?   
I want to make file_contents_type "private," ala Ada.  Is this even  
possible?

Example (pseudo-SML source)
---------------------------

structure MyModule:
  sig
	(* How can I do the following in SML?
	   datatype file_contents_type is private
	*)

	datatype file =
	  emptyfile
	| opened of {
		     (*some other fields here*)
		     contents:file_contents_type
		    };

	(*some other things in the sig here*)
  end =

  struct
	(* definition of file_contents_type here *)

	(* rest of definitions *)
end;


Please email replies to kleinjf@cs.rose-hulman.edu


Joel F. Klein

B.T.W., why is there so little activity in alt.lang.ml?