def sets(verb, typ, ctx):
"""
A rule to represent sets. Will only use specialized Dynamo sets, to abide by principle
of least astonishment.
Valid python types include Set[Decimal], Set[str], Set[bytes], or FrozenSet for any of
these. Also, any number that converts from Decimal and converts to a decimal if str is
called should work.
"""
if not has_origin(typ, (set, frozenset), num_args=1):
return
(inner,) = typ.__args__
con = get_origin(typ)
if inner == bytes:
if verb == DDB2PY:
return partial(decode_binary_set, con=con)
elif verb == PY2DDB:
return encode_binary_set
if inner != bool and issub_safe(inner, (Decimal, Real)):
if verb == DDB2PY:
return partial(decode_number_set, elem=inner, con=con)
elif verb == PY2DDB:
return encode_number_set
if inner == str:
if verb == DDB2PY:
return partial(decode_string_set, con=con)
elif verb == PY2DDB:
return encode_string_set
def dicts(verb, typ, ctx):
"""
A rule to represent lists as Dynamo list values.
"""
if verb not in _STRING_ACTIONS or not has_origin(typ, dict, num_args=2):
return
(key_typ, val_typ) = typ.__args__
inner_key = ctx.lookup(verb=_STRING_ACTIONS[verb], typ=key_typ)
inner_val = ctx.lookup(verb=verb, typ=val_typ)
if verb == DDB2PY:
return partial(
decode_dict, inner_key=inner_key, inner_val=inner_val, con=get_origin(typ)
)
elif verb == PY2DDB:
return partial(encode_dict, inner_key=inner_key, inner_val=inner_val)
def lists(verb, typ, ctx):
"""
A rule to represent lists as Dynamo list values.
"""
if has_origin(typ, list, num_args=1):
(inner,) = typ.__args__
elif has_origin(typ, tuple, num_args=2):
(inner, ell) = typ.__args__
if ell is not Ellipsis:
return
else:
return
inner = ctx.lookup(verb=verb, typ=inner)
if verb == DDB2PY:
return partial(decode_list, inner=inner, typ=get_origin(typ))
elif verb == PY2DDB:
return partial(encode_list, inner=inner)