{...}

    $some_value = old_parser_function_X (@args);
    
    {...}
    

##</code><code>##

    -- client code --
    {...}
    
    $some_value = generic_function_X (@args);
    
    {...}
    
    -- wrapper library --
    
    sub generic_function_X {
        return (old_parser_function_X (@_));
    }

##</code><code>##

    -- new wrapper --
    
    sub generic_function_X {
        {assemble a result by calling:
            new_parser_function_A (@some_args)
            new_parser_function_D (@some_other_args)
            new_parser_function_N (@still_more_args)
        }
        return ($result);
    }