DEFINITION Cmds

(* Glueck: select one or more sentences from a set of files per random *)
(* University of Ulm, SAI, Helmholtzstr. 18, D-7900 Ulm  --   AFB 7/92 *)

DEFINITION Cmds;

   IMPORT Streams;

   CONST
      unlimited = -1; (* for maxargs *)

      (* return values of Read *)
      unknown = -1; (* cmd not recognized *)
      done = -2; (* no further action necessary, e.g. usage has been printed *)
      error = -3; (* input errors occured *)
      empty = -4; (* empty input line *)
   
   TYPE
      Set = SET; (* set of command codes *)

   PROCEDURE Add(s: Streams.Stream;
		 code: INTEGER;        (* >=0, identifies the command *)
		 name: ARRAY OF CHAR;  (* name of the command *)
		 minargs: INTEGER;     (* minimal number of args *)
		 maxargs: INTEGER;     (* maximal number of args; -1=unltd *)
		 usage: ARRAY OF CHAR; (* usage text w/o Usage: and cmd name *)
		 help: ARRAY OF CHAR  (* short description *)
		 );

   PROCEDURE SetOutput(s, out: Streams.Stream);

   PROCEDURE Legal(s: Streams.Stream; set: Set);
      (* set the set of legal commands *)

   PROCEDURE Read(s: Streams.Stream;
		  VAR nfields: INTEGER;
		  VAR fields: ARRAY OF ARRAY OF CHAR) : INTEGER;
      (* read an entire line and return the command code together
	 with its fields
      *)

END Cmds.