def process(node, on_error=exc.raise_, db=None, preserve=set(), strip=False):

    '''Evaluates the XML functions in an XML tree.

    @param preserve set(str...) XML functions not to remove.

        * container can be any iterable type

    @param strip Whether to instead replace most XML functions with their last

        parameter (usually the value) and evaluate only structural functions

    '''

    preserve = set(preserve)

    for child in xml_dom.NodeElemIter(node):

        process(child, on_error, db, preserve, strip)

    if not is_xml_func_name(name) or name in preserve: pass

    elif strip and name not in structural_funcs: # just replace with last param

        value = pop_value(list(xml_dom.NodeTextEntryIter(node)), None)

        xml_dom.replace_with_text(node, value)

    else: