The following codes produces a syntax error on python: ```yaml meta: id: ops endian: le seq: - id: opcode type: u1 - id: arguments type: switch-on: opcode cases: _: u4 ``` the produced code is: ```python def _read(self): self.opcode = self._io.read_u1() _on = self.opcode else: self.arguments = self._io.read_u4le() ``` hence a "else" with no "if". Maybe this particular pattern should not be allowed ?