chore: updates operator reference to rely on json operator

Author: chalmerlowe

packages/sqlalchemy-bigquery/sqlalchemy_bigquery/_struct.py

@@ -20,6 +20,7 @@
 import sqlalchemy.sql.default_comparator
 import sqlalchemy.sql.sqltypes
 import sqlalchemy.types
+from sqlalchemy.sql import operators
 
 from . import base
 
@@ -90,7 +91,7 @@ def _setup_getitem(self, name):
             subtype = self.expr.type._STRUCT_byname.get(name.lower())
             if subtype is None:
                 raise KeyError(name)
-            operator = struct_getitem_op
+            operator = operators.json_getitem_op
             index = _field_index(self, name, operator)
             return operator, index, subtype
 
@@ -113,16 +114,8 @@ def _field_index(self, name, operator):
     )
 
 
-def struct_getitem_op(a, b):
-    raise NotImplementedError()
-
-
-sqlalchemy.sql.default_comparator.operator_lookup[
-    struct_getitem_op.__name__
-] = sqlalchemy.sql.default_comparator.operator_lookup["json_getitem_op"]
-
 
 class SQLCompiler:
-    def visit_struct_getitem_op_binary(self, binary, operator_, **kw):
+    def visit_json_getitem_op_binary(self, binary, operator_, **kw):
         left = self.process(binary.left, **kw)
         return f"{left}.{binary.right.value}"