(self)
| 56 | |
| 57 | @memoize |
| 58 | def grammar(self) -> Optional[Grammar]: |
| 59 | # grammar: metas rules | rules |
| 60 | mark = self._mark() |
| 61 | if ( |
| 62 | (metas := self.metas()) |
| 63 | and |
| 64 | (rules := self.rules()) |
| 65 | ): |
| 66 | return Grammar ( rules , metas ) |
| 67 | self._reset(mark) |
| 68 | if ( |
| 69 | (rules := self.rules()) |
| 70 | ): |
| 71 | return Grammar ( rules , [] ) |
| 72 | self._reset(mark) |
| 73 | return None |
| 74 | |
| 75 | @memoize |
| 76 | def metas(self) -> Optional[MetaList]: |