def test_multi_level(self):
x, y, z = 423, 324, 321
f1 = FieldExpression(x, y, ops.add)
f2 = FieldExpression(y, z, ops.add)
f3 = FieldExpression(f1, f2, ops.sub)
self.assertTrue(f3.eval() == ops.sub(ops.add(x, y), ops.add(y, z)))
self.assertTrue(f3.to_string() == "(423 + 324) - (324 + 321)")
def test_partly_evaluation(self):
x, y = 123, "varname"
f1 = FieldExpression(x, y, ops.add)
f2 = f1.eval()
self.assertTrue(isinstance(f1.eval(), FieldExpression))
self.assertTrue(f1.to_string() == "123 + varname")
f1.context["varname"] = 313
self.assertTrue(isinstance(f1.eval(), int))
self.assertTrue(f1.eval() == 436)