| 899 | @check_arg_types |
| 900 | @contextualized_operator |
| 901 | def _freeze( |
| 902 | self, |
| 903 | threshold_column: expr.ColumnExpression, |
| 904 | time_column: expr.ColumnExpression, |
| 905 | instance_column: expr.ColumnExpression | None = None, |
| 906 | ) -> Table[TSchema]: |
| 907 | # FIXME: freeze can be incorrect if the input is not append-only |
| 908 | # we may produce insertion but never produce deletion |
| 909 | if instance_column is None: |
| 910 | instance_column = expr.ColumnConstExpression(None) |
| 911 | context = clmn.FreezeContext( |
| 912 | self._id_column, |
| 913 | self._eval(threshold_column), |
| 914 | self._eval(time_column), |
| 915 | self._eval(instance_column), |
| 916 | ) |
| 917 | return self._table_with_context(context) |
| 918 | |
| 919 | @trace_user_frame |
| 920 | @desugar |