code: def memoized_parse_block(code):
      
      success, result = parse_block_memo.get(code, (None, None))
      if success is None:
          try:
              parsed = COMPILER.parse_block(code)
          except Exception as err:
              success, result = False, err
          else:
              success, result = True, parsed
          parse_block_memo[code] = (success, result)
      if success:
          return result
      else:
          raise result
docs: Memoized version of parse_block.