def is_hex_address(value: Any) -> bool:
"""Checks if the given string of text type is an address in hexadecimal encoded form."""
if len(value) != 42:
return False
elif not is_text(value):
return False
elif not is_hex(value):
return False
else:
return is_address(hex_to_base58(value))
def find_matching_fn_abi(abi, fn_identifier=None, args=None, kwargs=None):
args = args or tuple()
kwargs = kwargs or dict()
filters = []
num_arguments = len(args) + len(kwargs)
diagnosis = None
if fn_identifier is FallbackFn:
return get_fallback_func_abi(abi)
if not is_text(fn_identifier):
raise TypeError("Unsupported function identifier")
name_filter = functools.partial(filter_by_name, fn_identifier)
arg_count_filter = functools.partial(filter_by_argument_count,
num_arguments)
encoding_filter = functools.partial(filter_by_encodability, args, kwargs)
filters.extend([
name_filter,
arg_count_filter,
encoding_filter,
])
function_candidates = pipe(abi, *filters)
if len(function_candidates) == 1:
return function_candidates[0]
else:
matching_identifiers = name_filter(abi)
matching_function_signatures = [
abi_to_signature(func) for func in matching_identifiers
]
arg_count_matches = len(arg_count_filter(matching_identifiers))
encoding_matches = len(encoding_filter(matching_identifiers))
if arg_count_matches == 0:
diagnosis = "\nFunction invocation failed due to improper number of arguments."
elif encoding_matches == 0:
diagnosis = "\nFunction invocation failed due to no matching argument types."
elif encoding_matches > 1:
diagnosis = (
"\nAmbiguous argument encoding. "
"Provided arguments can be encoded to multiple functions matching this call."
)
message = (
"\nCould not identify the intended function with name `{name}`, "
"positional argument(s) of type `{arg_types}` and "
"keyword argument(s) of type `{kwarg_types}`."
"\nFound {num_candidates} function(s) with the name `{name}`: {candidates}"
"{diagnosis}").format(
name=fn_identifier,
arg_types=tuple(map(type, args)),
kwarg_types=valmap(type, kwargs),
num_candidates=len(matching_identifiers),
candidates=matching_function_signatures,
diagnosis=diagnosis,
)
raise ValueError(message)
def _set_function_info(self):
if not self.abi:
self.abi = find_matching_fn_abi(self.contract_abi,
self.function_identifier,
self.args, self.kwargs)
if self.function_identifier is FallbackFn:
self.selector = encode_hex(b'')
elif is_text(self.function_identifier):
self.selector = encode_hex(function_abi_to_4byte_selector(
self.abi))
else:
raise TypeError("Unsupported function identifier")
self.arguments = merge_args_and_kwargs(self.abi, self.args,
self.kwargs)