docs: def get_first_pos_of_char(char, string):
      '''
      :param char: The character to find
      :type char: string
      :param string: The string in which to search for *char*
      :type string: string
      :returns: Index in *string* where *char* last appears (unescaped by a preceding "\\"), -1 if not found
      :rtype: int
  
      Finds the first occurrence of *char* in *string* in which *char* is
      not present as an escaped character.
  
      '''
      first_pos = -1
      pos = len(string)
      while pos > 0:
          pos = string[:pos].rfind(char)
          if pos == -1:
              return first_pos
          num_backslashes = 0
          test_index = pos - 1
          while test_index >= 0 and string[test_index] == '\\':
              num_backslashes += 1
              test_index -= 1
          if num_backslashes % 2 == 0:
              first_pos = pos
      return first_pos