feat: add processor methods to BIT class

Author: jackrua

pgvector/sqlalchemy/bit.py

@@ -1,6 +1,8 @@
+import asyncpg
+from sqlalchemy.dialects.postgresql.asyncpg import PGDialect_asyncpg
 from sqlalchemy.dialects.postgresql.base import ischema_names
 from sqlalchemy.types import UserDefinedType, Float
-
+from .. import Bit
 
 class BIT(UserDefinedType):
     cache_ok = True
@@ -14,6 +16,21 @@ def get_col_spec(self, **kw):
             return 'BIT'
         return 'BIT(%d)' % self.length
 
+    def bind_processor(self, dialect):
+        def process(value):
+            value = Bit._to_db(value)
+            if value and isinstance(dialect, PGDialect_asyncpg): 
+                return asyncpg.BitString(value)
+            return value
+        return process
+    
+    def result_processor(self, dialect, coltype):
+        def process(value): 
+            if value and isinstance(dialect, PGDialect_asyncpg):
+                return value.as_string()
+            return Bit._from_db(value).to_text() 
+        return process
+
     class comparator_factory(UserDefinedType.Comparator):
         def hamming_distance(self, other):
             return self.op('<~>', return_type=Float)(other)