INTERFACE Material;

(* Physical properties of materials *)

IMPORT ParseParams;

TYPE
  T = RECORD 
      name: Name;
      density, alpha, beta, eta1, eta2: LONGREAL
    END;

  List = ARRAY OF T;
  Num = CARDINAL;     (* Index in a "List" *)
  Name = TEXT;

CONST None = LAST(CARDINAL); (* A NIL value for "Num" *)

PROCEDURE Find(READONLY mat: List; name: Name): Num;
  (*
    Looks for "name" in the given list. If it doesn't
    occur, returns "None" *)

CONST
  OptionsHelp = 
    "density NUM elasticity ALPHA BETA viscosity ETA1 ETA2";

PROCEDURE ParseOptions(pp: ParseParams.T): T RAISES{ParseParams.Error};
  (*
    Parses a material description from the command line,
    according to the syntax described in the "OptionsHelp" text above. *)

END Material.