GENERIC DEFINITION MODULE GStack (T : TYPE);
(* A generic linked stack over a type parameter T.  Instantiated as
   IntStack = GStack(INTEGER) and CharStack = GStack(CHAR). *)
TYPE
  Node = POINTER TO NodeRec;
  NodeRec = RECORD
    val  : T;
    next : Node;
  END;
  Stack = RECORD
    top   : Node;
    depth : INTEGER;
  END;
PROCEDURE Init(VAR s : Stack);
PROCEDURE Push(VAR s : Stack; v : T);
PROCEDURE Pop(VAR s : Stack; VAR v : T) : BOOLEAN;
PROCEDURE Depth(VAR s : Stack) : INTEGER;
END GStack.