dhall.dump(s) is able to generate mal-typed Dhall

[s-zeng]

Description

When passing mix-typed lists to dhall.dump(s), the resulting dhall that is outputted is not well-typed and cannot be read back with dhall.loads

Expected behaviour

python-dhall should error when receiving mal-typed inputs. For all inputs x, dhall.loads(dhall.dumps(x)) should either error on dumps, or be identitcal to the identity function on x, or else have some other way to translate heterogeneous lists and other dynamic data