def select_one_in(inst_set, where_cond):
inst_set = xtuml.QuerySet(inst_set)
cardinality = Runtime.cardinality(inst_set)
if cardinality > 1:
raise RuntimeException(
'select one from a set with cardinality %d' % cardinality)
return Runtime.select_any_in(inst_set, where_cond)
def select_many_in(inst_set, where_cond, order_by):
s = filter(where_cond, inst_set)
if order_by:
s = order_by(s)
return xtuml.QuerySet(s)
def cast_to_set(value):
if not isinstance(value, xtuml.QuerySet):
return xtuml.QuerySet([value])
else:
return value
def test_one_item(self):
q = xtuml.QuerySet([2])
self.assertEqual(q.first, 2)
self.assertEqual(q.last, 2)
def test_last(self):
q = xtuml.QuerySet([1, 2, 3])
self.assertEqual(q.last, 3)
q = xtuml.QuerySet()
self.assertIsNone(q.last)
def test_first(self):
q = xtuml.QuerySet([1, 2, 3])
self.assertEqual(q.first, 1)
q = xtuml.QuerySet()
self.assertIsNone(q.first)
def select_many_in(inst_set, where_cond):
s = filter(where_cond, inst_set)
return xtuml.QuerySet(s)