docs: def extract_angular(fileobj, keywords, comment_tags, options):
      """Extract messages from angular template (HTML) files that use the
      angular-gettext translate directive as per
      https://angular-gettext.rocketeer.be/ .
  
      :param fileobj: the file-like object the messages should be extracted
                      from
      :param keywords: This is a standard parameter so it is accepted but ignored.
  
      :param comment_tags: This is a standard parameter so it is accepted but
                          ignored.
      :param options: Another standard parameter that is accepted but ignored.
      :return: an iterator over ``(lineno, funcname, message, comments)``
               tuples
      :rtype: ``iterator``
  
      This particular extractor is quite simple because it is intended to only
      deal with angular templates which do not need comments, or the more
      complicated forms of translations.
  
      A later version will address pluralization.
      """
  
      if keywords:
          logging.debug('Parameter keywords ignored.')
  
      if comment_tags:
          logging.debug('Parameter comment_tags ignored.')
  
      if options:
          logging.debug('Parameter options ignored.')
  
      parser = AngularGettextHTMLParser()
  
      for line in fileobj:
          if not isinstance(line, str):
              line = line.decode(locale.getpreferredencoding())
          parser.feed(line)
  
      for string in parser.strings:
          yield(string)