(*
 * File to illustrate (and test) the various ways to do enums in RSL.
 *)

(*
 * Method 1: opaque types.
 *)

obj EnumType1 = a:A or b:B or c:C;
obj A;
obj B;
obj C;

op EnumTest1(e:EnumType1) = (
    e?.a;
    e?.A;	(* ERROR *)
);

(*
 * Method 2: sym lits.
 *)
obj EnumType2 = "a" or "b" or "c";

op EnumTest2(e:EnumType2) = (
    e = "a";
    e = "d";	(* ERROR *)
);

(*
 * Method 3: concrete string types.
 *)
obj EnumType3 = A3 or B3 or C3;
obj A3 = "A";
obj B3 = "B";
obj C3 = "C";

op EnumTest2(e:EnumType3) = (
    e = "A";
    e = "D";	(* ERROR *)
);

(*
 * Method 4: indirect sym lits.
 *)
obj EnumType4 = A4 or B4 or C4;
obj A4 = "a";
obj B4 = "b";
obj C4 = "c";

op EnumTest2(e:EnumType4) = (
    e = "a";
    e = "d";	(* ERROR *)
);