from sqlalchemy.dialects.postgresql.base import ischema_names
from sqlalchemy.types import UserDefinedType, Float
class BIT(UserDefinedType):
cache_ok = True
def __init__(self, length=None):
super(UserDefinedType, self).__init__()
self.length = length
def get_col_spec(self, **kw):
if self.length is None:
return 'BIT'
return 'BIT(%d)' % self.length
class comparator_factory(UserDefinedType.Comparator):
def hamming_distance(self, other):
return self.op('<~>', return_type=Float)(other)
def jaccard_distance(self, other):
return self.op('<%>', return_type=Float)(other)
# for reflection
ischema_names['bit'] = BIT