import xml.parsers.expat as expat

            while True:

                try: in_xml_root = minidom.parse(sys.stdin).documentElement

                except expat.ExpatError, e:

                    if str(e).startswith('no element found:'): break

                        # no more concatenated XML documents

                    else: raise e

                if map_path == None:

                    iter_ = xml_dom.NodeElemIter(in_xml_root)

                    util.skip(iter_, xml_dom.is_text) # skip metadata

                    row_ct = process_rows(lambda row, i: root.appendChild(row),

                        iter_)

                else:

                    rows = xpath.get(in_xml_root, in_root, limit=end)

                    if rows == []: raise SystemExit('Map error: Root "'+in_root

                        +'" not found in input')

                    def get_value(in_, row):

                        in_ = './{'+(','.join(strings.with_prefixes(

                            ['']+prefixes, in_)))+'}' # also with no prefix

                        nodes = xpath.get(row, in_, allow_rooted=False)

                        if nodes != []: return xml_dom.value(nodes[0])

                        else: return None

                    row_ct = map_rows(get_value, rows)