new_line += affects_new

                            lines.append({

                                'old_lineno':   affects_old and old_line or '',

                                'new_lineno':   affects_new and new_line or '',

                                'action':       action,

                                'line':         line

                            })

                        line = lineiter.next()

        except StopIteration:

            pass

        sorter = lambda info: {'A': 0, 'M': 1, 'D': 2}.get(info['operation'])

        if inline_diff is False:

            return sorted(files, key=sorter)

        # highlight inline changes

        for diff_data in files:

            for chunk in diff_data['chunks']:

                lineiter = iter(chunk)

                try:

                    while 1:

                        line = lineiter.next()

                            nextline = lineiter.next()

                            if nextline['action'] in ['unmod', 'context'] or \

                               nextline['action'] == line['action']:

                                continue

                            self.differ(line, nextline)

                except StopIteration:

                    pass

        return sorted(files, key=sorter)

    def prepare(self, inline_diff=True):

        """

        Prepare the passed udiff for HTML rendering. It'l return a list

        of dicts

        """

        return self._parse_udiff(inline_diff=inline_diff)

    def _safe_id(self, idstring):

        """Make a string safe for including in an id attribute.

        The HTML spec says that id attributes 'must begin with

        a letter ([A-Za-z]) and may be followed by any number

        of letters, digits ([0-9]), hyphens ("-"), underscores

        ("_"), colons (":"), and periods (".")'. These regexps