PACKAGE paramlist_pkg 
IS
	-- A function which initializes a parameter list.
	FUNCTION initialize (parm_list_name_in IN VARCHAR2) RETURN PARAMLIST;

	/* The overloaded add procedures: */
	PROCEDURE add 
		(pl_id_in IN PARAMLIST, name_in IN VARCHAR2, value_in IN VARCHAR2);
	PROCEDURE add 
		(pl_id_in IN PARAMLIST, name_in IN VARCHAR2, value_in IN NUMBER);
	PROCEDURE add 
			(pl_id_in IN PARAMLIST, name_in IN VARCHAR2, value_in IN DATE,
 			 format_mask_in IN VARCHAR2 := 'MM/DD/YY');
END paramlist_pkg;

PACKAGE BODY paramlist_pkg IS
	/*
	|| First things first:
	|| Rather than require a developer to write the code to check for the 
	|| existence of a parameter list, then destroy and re-create it to 
	|| assure oneself of a "clean" list, I can move such code into a very
	|| general function that takes the name of the parameter list and 
	|| returns the pointer to the parameter list.
	*/
	FUNCTION initialize (parm_list_name_in IN VARCHAR2) RETURN PARAMLIST 
	IS
		return_value PARAMLIST
	BEGIN
		return_value := GET_PARAMETER_LIST (parm_list_name_in);
		IF NOT ID_NULL (return_value)
		THEN
			DESTROY_PARAMETER_LIST (return_value);
		END IF;
		RETURN CREATE_PARAMETER_LIST (parm_list_name_in);
	END initialize;
	/*
	|| Now my overloaded add procedures. Notice that they only have three 
	|| arguments, as opposed to the four of the ADD_PARAMETER built-in.
	|| The only difference between these three versions of add is the 
	|| datatype of the last argument: VARCHAR2, NUMBER or DATE.
	*/
	PROCEDURE add 
		(pl_id_in IN PARAMLIST, name_in IN VARCHAR2, value_in IN VARCHAR2)
	IS
	BEGIN
		ADD_PARAMETER (pl_id_in, name_in, TEXT_PARAMETER, value_in);
	END;

	PROCEDURE add 
		(pl_id_in IN PARAMLIST, name_in IN VARCHAR2, value_in IN NUMBER)
	IS
	BEGIN
		ADD_PARAMETER 
			(pl_id_in, name_in, TEXT_PARAMETER, TO_CHAR (value_in));
	END;

	PROCEDURE add 
			(pl_id_in IN PARAMLIST, name_in IN VARCHAR2, value_in IN DATE,
 			 format_mask_in IN VARCHAR2 := 'MM/DD/YY')
	IS
	BEGIN
		ADD_PARAMETER (pl_id_in, name_in, TEXT_PARAMETER, 
			 			   TO_CHAR (value_in, format_mask_in IN VARCHAR2));
	END;
END paramlist_pkg;