Support anonymous fields/arguments

Author: fjarri

docs/api.rst

@@ -151,6 +151,17 @@ Contract ABI
 .. autoclass:: Receive
    :members:
 
+.. autoclass:: Fields
+   :members:
+
+.. autoclass:: EventFields
+   :members:
+   :show-inheritance:
+
+.. autoclass:: FieldValues
+   :members:
+   :special-members: __getitem__, __getattr__
+
 
 Testing utilities
 -----------------
@@ -255,12 +266,6 @@ Utility classes
 
    Generic method type parameter.
 
-.. autoclass:: pons._contract_abi.Signature()
-   :members: canonical_form
-
-.. autoclass:: pons._contract_abi.Method
-   :members:
-
 
 Utility methods
 ---------------

docs/changelog.rst

@@ -2,18 +2,31 @@ Changelog
 ---------
 
 
-0.10.1 (in development)
+0.11.0 (in development)
 ~~~~~~~~~~~~~~~~~~~~~~~
 
+Changed
+^^^^^^^
+
+- ``ContractABI`` interface modified to allow for methods, errors, and events with arbitrary anonymous parameters and fields. Instead of returning ``dict[str, Any]`` as a parsed struct we now return a ``FieldValues`` object. Signatures of methods and fields of errors are exposed as ``Fields``, fields of events are exposed as ``EventFields`` objects. (PR_92_)
+
+
 Added
 ^^^^^
 
 - Support for contract errors with anonymous fields. (PR_90_)
 - Support for partially named method arguments. (PR_91_)
 
 
+Fixed
+^^^^^
+
+- Name disambiguation for method parameters and struct fields. (PR_92_)
+
+
 .. _PR_90: https://github.com/fjarri-eth/pons/pull/90
 .. _PR_91: https://github.com/fjarri-eth/pons/pull/91
+.. _PR_92: https://github.com/fjarri-eth/pons/pull/92
 
 
 0.10.0 (2025-10-19)

pons/__init__.py

@@ -35,8 +35,11 @@
     Either,
     Error,
     Event,
+    EventFields,
     EventFilter,
     Fallback,
+    Fields,
+    FieldValues,
     Method,
     MethodCall,
     MultiMethod,
@@ -94,11 +97,14 @@
     "Either",
     "Error",
     "Event",
+    "EventFields",
     "EventFilter",
     "Fallback",
     "FallbackProvider",
     "FallbackStrategy",
     "FallbackStrategyFactory",
+    "FieldValues",
+    "Fields",
     "HTTPError",
     "HTTPProvider",
     "InvalidResponse",

pons/_abi_types.py

@@ -506,23 +506,13 @@ def dispatch_type(abi_entry: ABI_JSON) -> Type:
     return type_from_abi_string(element_type_name)
 
 
-def dispatch_types(abi_entry: ABI_JSON) -> list[Type] | dict[str, Type]:
+def dispatch_parameter_types(abi_entry: ABI_JSON) -> list[tuple[str | None, Type]]:
     # TODO (#83): use proper validation
     abi_entry_typed = cast("Iterable[dict[str, Any]]", abi_entry)
-
-    names = [entry["name"] for entry in abi_entry_typed]
-
-    # In Solidity, it is possible to have have an argument list like `(address x, uint256)`
-    # (that is, only some of the arguments are unnamed).
-    # This cannot be mapped to Python function signatures,
-    # so we have to treat this as if all the arguments were unnamed.
-    if names and any(not name for name in names):
-        return [dispatch_type(entry) for entry in abi_entry_typed]
-
-    # Since we are returning a dictionary, need to be sure we don't silently merge entries
-    if len(names) != len(set(names)):
-        raise ValueError("All ABI entries must have distinct names")
-    return {entry["name"]: dispatch_type(entry) for entry in abi_entry_typed}
+    return [
+        (entry["name"] if entry["name"] != "" else None, dispatch_type(entry))
+        for entry in abi_entry_typed
+    ]
 
 
 def encode_args(*types_and_args: tuple[Type, Any]) -> bytes:

pons/_client.py

@@ -36,6 +36,7 @@
     ContractABI,
     Error,
     EventFilter,
+    FieldValues,
     UnknownError,
 )
 from ._provider import Provider, ProviderError, ProviderSession
@@ -156,10 +157,10 @@ class ContractError(Exception):
     error: Error
     """The recognized ABI Error object."""
 
-    data: dict[str, Any] | tuple[Any, ...]
+    data: FieldValues
     """The unpacked error data, corresponding to the ABI."""
 
-    def __init__(self, error: Error, decoded_data: dict[str, Any] | tuple[Any, ...]):
+    def __init__(self, error: Error, decoded_data: FieldValues):
         super().__init__(error, decoded_data)
         self.error = error
         self.data = decoded_data
@@ -189,14 +190,16 @@ def decode_contract_error(
         except UnknownError:
             return ProviderError(exc)
 
-        # These errors have named fields, so `decoded_data` is expected to be a dictionary.
-        # The assertions are there for `mypy`'s sake.
         if error == PANIC_ERROR:
-            assert isinstance(decoded_data, dict)  # noqa: S101
-            return ContractPanic.from_code(decoded_data["code"])
+            # If `resolve_error()` finished successfully,
+            # `code` will be present in `decoded_data`
+            # since it is declared as a field in the PANIC_ERROR
+            return ContractPanic.from_code(decoded_data.as_dict["code"])
         if error == LEGACY_ERROR:
-            assert isinstance(decoded_data, dict)  # noqa: S101
-            return ContractLegacyError(decoded_data["message"])
+            # If `resolve_error()` finished successfully,
+            # `message` will be present in `decoded_data`
+            # since it is declared as a field in the PANIC_ERROR
+            return ContractLegacyError(decoded_data.as_dict["message"])
 
         return ContractError(error, decoded_data)
     return ProviderError(exc)
@@ -519,7 +522,7 @@ async def transact(
         amount: None | Amount = None,
         gas: None | int = None,
         return_events: None | Sequence[BoundEvent] = None,
-    ) -> dict[BoundEvent, list[dict[str, Any]]]:
+    ) -> dict[BoundEvent, list[FieldValues]]:
         """
         Transacts with the contract using a prepared method call.
         If ``gas`` is ``None``, the required amount of gas is estimated first,
@@ -594,7 +597,7 @@ async def iter_events(
         poll_interval: int = 1,
         from_block: Block = BlockLabel.LATEST,
         to_block: Block = BlockLabel.LATEST,
-    ) -> AsyncIterator[dict[str, Any]]:
+    ) -> AsyncIterator[FieldValues]:
         """
         Yields decoded log entries produced by the filter.
         The fields that were hashed when converted to topics (that is, fields of reference types)

pons/_contract.py

@@ -9,6 +9,7 @@
     Error,
     Event,
     EventFilter,
+    FieldValues,
     Method,
     Methods,
     MultiMethod,
@@ -169,7 +170,7 @@ def __init__(self, contract_address: Address, event: Event, event_filter: EventF
         self.topics = event_filter.topics
         self._event = event
 
-    def decode_log_entry(self, log_entry: LogEntry) -> dict[str, Any]:
+    def decode_log_entry(self, log_entry: LogEntry) -> FieldValues:
         if log_entry.address != self.contract_address:
             raise ValueError("Log entry originates from a different contract")
         return self._event.decode_log_entry(log_entry)