def parse_node(self, block=False, indentless_sequence=False):
        if self.check_token(AliasToken):
            token = self.get_token()
            event = AliasEvent(token.value, token.start_mark, token.end_mark)
            self.state = self.states.pop()
        else:
            anchor = None
            tag = None
            start_mark = end_mark = tag_mark = None
            if self.check_token(AnchorToken):
                token = self.get_token()
                start_mark = token.start_mark
                end_mark = token.end_mark
                anchor = token.value
                if self.check_token(TagToken):
                    token = self.get_token()
                    tag_mark = token.start_mark
                    end_mark = token.end_mark
                    tag = token.value
            elif self.check_token(TagToken):
                token = self.get_token()
                start_mark = tag_mark = token.start_mark
                end_mark = token.end_mark
                tag = token.value
                if self.check_token(AnchorToken):
                    token = self.get_token()
                    end_mark = token.end_mark
                    anchor = token.value
            if tag is not None:
                handle, suffix = tag
                if handle is not None:
                    if handle not in self.tag_handles:
                        raise ParserError("while parsing a node", start_mark,
                                "found undefined tag handle %r" % handle.encode('utf-8'),
                                tag_mark)
                    tag = self.tag_handles[handle]+suffix
                else:
                    tag = suffix
            #if tag == u'!':
            #    raise ParserError("while parsing a node", start_mark,
            #            "found non-specific tag '!'", tag_mark,
            #            "Please check 'http://pyyaml.org/wiki/YAMLNonSpecificTag' and share your opinion.")
            if start_mark is None:
                start_mark = end_mark = self.peek_token().start_mark
            event = None
            implicit = (tag is None or tag == u'!')
            if indentless_sequence and self.check_token(BlockEntryToken):
                end_mark = self.peek_token().end_mark
                event = SequenceStartEvent(anchor, tag, implicit,
                        start_mark, end_mark)
                self.state = self.parse_indentless_sequence_entry
            else:
                if self.check_token(ScalarToken):
                    token = self.get_token()
                    end_mark = token.end_mark
                    if (token.plain and tag is None) or tag == u'!':
                        implicit = (True, False)
                    elif tag is None:
                        implicit = (False, True)
                    else:
                        implicit = (False, False)
                    event = ScalarEvent(anchor, tag, implicit, token.value,
                            start_mark, end_mark, style=token.style)
                    self.state = self.states.pop()
                elif self.check_token(FlowSequenceStartToken):
                    end_mark = self.peek_token().end_mark
                    event = SequenceStartEvent(anchor, tag, implicit,
                            start_mark, end_mark, flow_style=True)
                    self.state = self.parse_flow_sequence_first_entry
                elif self.check_token(FlowMappingStartToken):
                    end_mark = self.peek_token().end_mark
                    event = MappingStartEvent(anchor, tag, implicit,
                            start_mark, end_mark, flow_style=True)
                    self.state = self.parse_flow_mapping_first_key
                elif block and self.check_token(BlockSequenceStartToken):
                    end_mark = self.peek_token().start_mark
                    event = SequenceStartEvent(anchor, tag, implicit,
                            start_mark, end_mark, flow_style=False)
                    self.state = self.parse_block_sequence_first_entry
                elif block and self.check_token(BlockMappingStartToken):
                    end_mark = self.peek_token().start_mark
                    event = MappingStartEvent(anchor, tag, implicit,
                            start_mark, end_mark, flow_style=False)
                    self.state = self.parse_block_mapping_first_key
                elif anchor is not None or tag is not None:
                    # Empty scalars are allowed even if a tag or an anchor is
                    # specified.
                    event = ScalarEvent(anchor, tag, (implicit, False), u'',
                            start_mark, end_mark)
                    self.state = self.states.pop()
                else:
                    if block:
                        node = 'block'
                    else:
                        node = 'flow'
                    token = self.peek_token()
                    raise ParserError("while parsing a %s node" % node, start_mark,
                            "expected the node content, but found %r" % token.id,
                            token.start_mark)
        return event

    # block_sequence ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/yaml-3.10/yaml/parser.py/Parser.parse_node/original