code: def fast_search(self, pattern_codes):
          
          # pattern starts with a known prefix
          # <5=length> <6=skip> <7=prefix data> <overlap data>
          flags = pattern_codes[2]
          prefix_len = pattern_codes[5]
          prefix_skip = pattern_codes[6] # don't really know what this is good for
          prefix = pattern_codes[7:7 + prefix_len]
          overlap = pattern_codes[7 + prefix_len - 1:pattern_codes[1] + 1]
          pattern_codes = pattern_codes[pattern_codes[1] + 1:]
          i = 0
          string_position = self.string_position
          while string_position < self.end:
              while True:
                  if ord(self.string[string_position]) != prefix[i]:
                      if i == 0:
                          break
                      else:
                          i = overlap[i]
                  else:
                      i += 1
                      if i == prefix_len:
                          # found a potential match
                          self.start = string_position + 1 - prefix_len
                          self.string_position = string_position + 1 \
                                                       - prefix_len + prefix_skip
                          if flags & SRE_INFO_LITERAL:
                              return True # matched all of pure literal pattern
                          if self.match(pattern_codes[2 * prefix_skip:]):
                              return True
                          i = overlap[i]
                      break
              string_position += 1
          return False
docs: Skips forward in a string as fast as possible using information from
          an optimization info block.