CREATE OR REPLACE PACKAGE dyn
IS
   /* TVP 5/99 Suggestion: */
   TYPE args_tabtype IS TABLE OF VARCHAR2(2000) 
      INDEX BY BINARY_INTEGER;
   
   FUNCTION calc (
      oper_in IN VARCHAR2,
      args IN args_tabtype)
   RETURN VARCHAR2;
   
   FUNCTION calc (
      oper_in IN VARCHAR2,
      nargs_in IN PLS_INTEGER := 0,
      arg1_in IN VARCHAR2 := NULL,
      arg2_in IN VARCHAR2 := NULL,
      arg3_in IN VARCHAR2 := NULL,
      arg4_in IN VARCHAR2 := NULL,
      arg5_in IN VARCHAR2 := NULL,
      arg6_in IN VARCHAR2 := NULL,
      arg7_in IN VARCHAR2 := NULL,
      arg8_in IN VARCHAR2 := NULL,
      arg9_in IN VARCHAR2 := NULL,
      arg10_in IN VARCHAR2 := NULL
      )
   RETURN VARCHAR2;
END;
/
   
CREATE OR REPLACE PACKAGE BODY dyn
IS
   FUNCTION valfromstr (str IN VARCHAR2) RETURN VARCHAR2
   IS
      retval PLV.maxvc2;
   BEGIN
      EXECUTE IMMEDIATE str
         USING IN OUT retval;

      RETURN retval; 
   EXCEPTION
      WHEN OTHERS
   	  THEN
   	      do.pl /* do.pkg */ (SQLERRM);
          do.pl /* do.pkg */ (str);
          RETURN NULL;
   END;
   
   FUNCTION calc (
      oper_in IN VARCHAR2,
      args IN args_tabtype)
   RETURN VARCHAR2
   IS
      v_code PLV.maxvc2 := 'BEGIN :outcome := ' || oper_in;
      indx PLS_INTEGER := args.FIRST;
   BEGIN
      do.pl /* do.pkg */ (v_code);
      IF indx IS NOT NULL
      THEN
         v_code := v_code || '(';
         
         LOOP
            EXIT WHEN indx IS NULL;
            v_code := v_code || NVL (args(indx), 'NULL') || ',';
            indx := args.NEXT (indx);
         END LOOP;

         v_code := RTRIM (v_code, ',') || ')'; 
         
         do.pl /* do.pkg */ (v_code);
      END IF;
      
      v_code := v_code || '; END;';

      do.pl /* do.pkg */ (v_code);
      
      RETURN valfromstr (v_code);
   END;

   FUNCTION calc (
      oper_in IN VARCHAR2,
      nargs_in IN PLS_INTEGER := 0,
      arg1_in IN VARCHAR2 := NULL,
      arg2_in IN VARCHAR2 := NULL,
      arg3_in IN VARCHAR2 := NULL,
      arg4_in IN VARCHAR2 := NULL,
      arg5_in IN VARCHAR2 := NULL,
      arg6_in IN VARCHAR2 := NULL,
      arg7_in IN VARCHAR2 := NULL,
      arg8_in IN VARCHAR2 := NULL,
      arg9_in IN VARCHAR2 := NULL,
      arg10_in IN VARCHAR2 := NULL
      )
   RETURN VARCHAR2
   IS
      v_args args_tabtype;
   BEGIN
      IF nargs_in >= 1 THEN v_args(1) := arg1_in; END IF;
      IF nargs_in >= 2 THEN v_args(2) := arg2_in; END IF;
      IF nargs_in >= 3 THEN v_args(3) := arg3_in; END IF;
      IF nargs_in >= 4 THEN v_args(4) := arg4_in; END IF;
      IF nargs_in >= 5 THEN v_args(5) := arg5_in; END IF;
      IF nargs_in >= 6 THEN v_args(6) := arg6_in; END IF;
      IF nargs_in >= 7 THEN v_args(7) := arg7_in; END IF;
      IF nargs_in >= 8 THEN v_args(8) := arg8_in; END IF;
      IF nargs_in >= 9 THEN v_args(9) := arg9_in; END IF;
      IF nargs_in >= 10 THEN v_args(10) := arg10_in; END IF;
      RETURN calc (oper_in, v_args);
   END;
END;
/


/*======================================================================
| Supplement to the third edition of Oracle PL/SQL Programming by Steven
| Feuerstein with Bill Pribyl, Copyright (c) 1997-2002 O'Reilly &
| Associates, Inc. To submit corrections or find more code samples visit
| http://www.oreilly.com/catalog/oraclep3/
*/