tractor/_context.py

@@ -49,21 +49,20 @@ from ._exceptions import (
     InternalError,
     RemoteActorError,
     StreamOverrun,
-    pack_from_raise,
+    pack_error,
     unpack_error,
     _raise_from_no_key_in_msg,
 )
 from .log import get_logger
 from .msg import (
-    Error,
-    MsgType,
-    MsgCodec,
     NamespacePath,
+    Msg,
     Return,
     Started,
     Stop,
     Yield,
     current_codec,
+    MsgCodec,
     pretty_struct,
 )
 from ._ipc import Channel
@@ -108,7 +107,8 @@ async def _drain_to_final_msg(
     # wait for a final context result by collecting (but
     # basically ignoring) any bi-dir-stream msgs still in transit
     # from the far end.
-    pre_result_drained: list[MsgType] = []
+    # pre_result_drained: list[dict] = []
+    pre_result_drained: list[Msg] = []
     while not (
         ctx.maybe_error
         and not ctx._final_result_is_set()
@@ -168,7 +168,7 @@ async def _drain_to_final_msg(
 
             # pray to the `trio` gawds that we're corrent with this
             # msg: dict = await ctx._recv_chan.receive()
-            msg: MsgType = await ctx._recv_chan.receive()
+            msg: Msg = await ctx._recv_chan.receive()
             # always capture unexpected/non-result msgs
             pre_result_drained.append(msg)
 
@@ -191,12 +191,13 @@ async def _drain_to_final_msg(
             raise
 
         match msg:
-
-            # final result arrived!
             case Return(
-                # cid=cid,
+                cid=cid,
                 pld=res,
             ):
+        # try:
+            # ctx._result: Any = msg['return']
+            # ctx._result: Any = msg.pld
                 ctx._result: Any = res
                 log.runtime(
                     'Context delivered final draining msg:\n'
@@ -209,9 +210,13 @@ async def _drain_to_final_msg(
                 # TODO: ^ we don't need it right?
                 break
 
-            # far end task is still streaming to us so discard
+        # except KeyError:
-            # and report depending on local ctx state.
+        # except AttributeError:
             case Yield():
+            # if 'yield' in msg:
+
+                # far end task is still streaming to us so discard
+                # and report per local context state.
                 if (
                     (ctx._stream.closed
                      and (reason := 'stream was already closed')
@@ -252,34 +257,45 @@ async def _drain_to_final_msg(
                     )
                     continue
 
-            # stream terminated, but no result yet..
-            #
             # TODO: work out edge cases here where
             # a stream is open but the task also calls
             # this?
             # -[ ] should be a runtime error if a stream is open right?
             # Stop()
             case Stop():
+            # elif 'stop' in msg:
                 log.cancel(
                     'Remote stream terminated due to "stop" msg:\n\n'
                     f'{pformat(msg)}\n'
                 )
                 continue
 
-            # remote error msg, likely already handled inside
+            # It's an internal error if any other msg type without
-            # `Context._deliver_msg()`
+            # a`'cid'` field arrives here!
-            case Error():
+            case _:
+            # if not msg.get('cid'):
+                if not msg.cid:
+                    raise InternalError(
+                        'Unexpected cid-missing msg?\n\n'
+                        f'{msg}\n'
+                    )
 
-                # TODO: can we replace this with `ctx.maybe_raise()`?
+                # XXX fallthrough to handle expected error XXX
-                # -[ ]  would this be handier for this case maybe?
+                # TODO: replace this with `ctx.maybe_raise()`
+                #
+                # TODO: would this be handier for this case maybe?
                 # async with maybe_raise_on_exit() as raises:
                 #     if raises:
                 #         log.error('some msg about raising..')
-                #
+
                 re: Exception|None = ctx._remote_error
                 if re:
+                    log.critical(
+                        'Remote ctx terminated due to "error" msg:\n'
+                        f'{re}'
+                    )
                     assert msg is ctx._cancel_msg
-                    # NOTE: this solved a super duper edge case XD
+                    # NOTE: this solved a super dupe edge case XD
                     # this was THE super duper edge case of:
                     # - local task opens a remote task,
                     # - requests remote cancellation of far end
@@ -296,10 +312,9 @@ async def _drain_to_final_msg(
                     #   does not re-raise any ctxc it receives
                     #   IFF **it** was the cancellation
                     #   requester..
-                    #
+                    # will raise if necessary, ow break from
-                    # XXX will raise if necessary but ow break
+                    # loop presuming any error terminates the
-                    # from loop presuming any supressed error
+                    # context!
-                    # (ctxc) should terminate the context!
                     ctx._maybe_raise_remote_err(
                         re,
                         # NOTE: obvi we don't care if we
@@ -323,7 +338,6 @@ async def _drain_to_final_msg(
                     log.critical('SHOULD NEVER GET HERE!?')
                     assert msg is ctx._cancel_msg
                     assert error.msgdata == ctx._remote_error.msgdata
-                    assert error.ipc_msg == ctx._remote_error.ipc_msg
                     from .devx._debug import pause
                     await pause()
                     ctx._maybe_cancel_and_set_remote_error(error)
@@ -332,20 +346,6 @@ async def _drain_to_final_msg(
                 else:
                     # bubble the original src key error
                     raise
-
-            # XXX should pretty much never get here unless someone
-            # overrides the default `MsgType` spec.
-            case _:
-                # It's definitely an internal error if any other
-                # msg type without a`'cid'` field arrives here!
-                if not msg.cid:
-                    raise InternalError(
-                        'Unexpected cid-missing msg?\n\n'
-                        f'{msg}\n'
-                    )
-
-                raise RuntimeError('Unknown msg type: {msg}')
-
     else:
         log.cancel(
             'Skipping `MsgStream` drain since final outcome is set\n\n'
@@ -1342,11 +1342,8 @@ class Context:
             # `._cancel_called == True`.
             not raise_overrun_from_self
             and isinstance(remote_error, RemoteActorError)
-
+            and remote_error.msgdata['boxed_type_str'] == 'StreamOverrun'
-            and remote_error.boxed_type_str == 'StreamOverrun'
+            and tuple(remote_error.msgdata['sender']) == our_uid
-
-            # and tuple(remote_error.msgdata['sender']) == our_uid
-            and tuple(remote_error.sender) == our_uid
         ):
             # NOTE: we set the local scope error to any "self
             # cancellation" error-response thus "absorbing"
@@ -1415,11 +1412,16 @@ class Context:
 
         assert self._recv_chan
         raise_overrun: bool = not self._allow_overruns
+        # res_placeholder: int = id(self)
         if (
+            # self._result == res_placeholder
+            # and not self._remote_error
             self.maybe_error is None
-            and
+            # not self._remote_error
-            not self._recv_chan._closed  # type: ignore
+            # and not self._local_error
+            and not self._recv_chan._closed  # type: ignore
         ):
+
             # wait for a final context result/error by "draining"
             # (by more or less ignoring) any bi-dir-stream "yield"
             # msgs still in transit from the far end.
@@ -1430,6 +1432,7 @@ class Context:
             for msg in drained_msgs:
 
                 # TODO: mask this by default..
+                # if 'return' in msg:
                 if isinstance(msg, Return):
                     # from .devx import pause
                     # await pause()
@@ -1445,9 +1448,6 @@ class Context:
             )
 
         self.maybe_raise(
-            # NOTE: obvi we don't care if we
-            # overran the far end if we're already
-            # waiting on a final result (msg).
             raise_overrun_from_self=(
                 raise_overrun
                 and
@@ -1458,12 +1458,34 @@ class Context:
                 (not self._cancel_called)
             )
         )
+        # if (
+        #     (re := self._remote_error)
+        #     # and self._result == res_placeholder
+        # ):
+        #     self._maybe_raise_remote_err(
+        #         re,
+        #         # NOTE: obvi we don't care if we
+        #         # overran the far end if we're already
+        #         # waiting on a final result (msg).
+        #         # raise_overrun_from_self=False,
+        #         raise_overrun_from_self=(
+        #             raise_overrun
+        #             and
+        #             # only when we ARE NOT the canceller
+        #             # should we raise overruns, bc ow we're
+        #             # raising something we know might happen
+        #             # during cancellation ;)
+        #             (not self._cancel_called)
+        #         ),
+        #     )
+            # if maybe_err:
+            #     self._result = maybe_err
+
         return self.outcome
 
-    # TODO: switch this with above!
+    # TODO: switch this with above which should be named
-    # -[ ] should be named `.wait_for_outcome()` and instead do
+    # `.wait_for_outcome()` and instead do
     # a `.outcome.Outcome.unwrap()` ?
-    #
     # @property
     # def result(self) -> Any|None:
     #     if self._final_result_is_set():
@@ -1522,6 +1544,7 @@ class Context:
         return None
 
     def _final_result_is_set(self) -> bool:
+        # return not (self._result == id(self))
         return self._result is not Unresolved
 
     # def get_result_nowait(self) -> Any|None:
@@ -1738,7 +1761,8 @@ class Context:
 
     async def _deliver_msg(
         self,
-        msg: MsgType,
+        # msg: dict,
+        msg: Msg,
 
     ) -> bool:
         '''
@@ -1752,20 +1776,6 @@ class Context:
         `._scope_nursery: trio.Nursery`) which ensures that such
         messages are queued up and eventually sent if possible.
 
-         XXX RULES XXX
-        ------ - ------
-        - NEVER raise remote errors from this method; a runtime task caller.
-          An error "delivered" to a ctx should always be raised by
-          the corresponding local task operating on the
-          `Portal`/`Context` APIs.
-
-        - NEVER `return` early before delivering the msg!
-          bc if the error is a ctxc and there is a task waiting on
-          `.result()` we need the msg to be
-          `send_chan.send_nowait()`-ed over the `._recv_chan` so
-          that the error is relayed to that waiter task and thus
-          raised in user code!
-
         '''
         cid: str = self.cid
         chan: Channel = self.chan
@@ -1796,14 +1806,28 @@ class Context:
             )
             self._cancel_msg: dict = msg
 
-            # XXX NOTE: this will not raise an error, merely set
+            # NOTE: this will not raise an error, merely set
             # `._remote_error` and maybe cancel any task currently
             # entered in `Portal.open_context()` presuming the
             # error is "cancel causing" (i.e. a `ContextCancelled`
             # or `RemoteActorError`).
             self._maybe_cancel_and_set_remote_error(re)
 
-        # XXX only case where returning early is fine!
+            # XXX NEVER do this XXX..!!
+            # bc if the error is a ctxc and there is a task
+            # waiting on `.result()` we need the msg to be sent
+            # over the `send_chan`/`._recv_chan` so that the error
+            # is relayed to that waiter task..
+            # return True
+            #
+            # XXX ALSO NO!! XXX
+            # => NEVER raise remote errors from the calling
+            # runtime task, they should always be raised by
+            # consumer side tasks operating on the
+            # `Portal`/`Context` APIs.
+            # if self._remote_error:
+            #     self._maybe_raise_remote_err(error)
+
         if self._in_overrun:
             log.warning(
                 f'Queueing OVERRUN msg on caller task:\n'
@@ -1922,13 +1946,17 @@ class Context:
                         # anything different.
                         return False
             else:
+                # txt += f'\n{msg}\n'
                 # raise local overrun and immediately pack as IPC
                 # msg for far end.
-                err_msg: Error = pack_from_raise(
+                try:
-                    local_err=StreamOverrun(
+                    raise StreamOverrun(
                         txt,
                         sender=from_uid,
-                    ),
+                    )
+                except StreamOverrun as err:
+                    err_msg: dict[str, dict] = pack_error(
+                        err,
                         cid=cid,
                     )
                     try:
@@ -1936,9 +1964,9 @@ class Context:
                         await chan.send(err_msg)
                         return True
 
-                # XXX: local consumer has closed their side of
-                # the IPC so cancel the far end streaming task
                     except trio.BrokenResourceError:
+                        # XXX: local consumer has closed their side
+                        # so cancel the far end streaming task
                         log.warning(
                             'Channel for ctx is already closed?\n'
                             f'|_{chan}\n'
@@ -2351,17 +2379,28 @@ async def open_context_from_portal(
             # an exception type boxed in a `RemoteActorError`
             # is returned (meaning it was obvi not raised)
             # that we want to log-report on.
-            match result_or_err:
+            msgdata: str|None = getattr(
-                case ContextCancelled() as ctxc:
+                result_or_err,
-                    log.cancel(ctxc.tb_str)
+                'msgdata',
+                None
+            )
+            match (msgdata, result_or_err):
+                case (
+                    {'tb_str': tbstr},
+                    ContextCancelled(),
+                ):
+                    log.cancel(tbstr)
 
-                case RemoteActorError() as rae:
+                case (
+                    {'tb_str': tbstr},
+                    RemoteActorError(),
+                ):
                     log.exception(
                         'Context remotely errored!\n'
                         f'<= peer: {uid}\n'
                         f'  |_ {nsf}()\n\n'
 
-                        f'{rae.tb_str}'
+                        f'{tbstr}'
                     )
                 case (None, _):
                     log.runtime(
@@ -2371,6 +2410,7 @@ async def open_context_from_portal(
 
                         f'`{result_or_err}`\n'
                     )
+
     finally:
         # XXX: (MEGA IMPORTANT) if this is a root opened process we
         # wait for any immediate child in debug before popping the

tractor/_ipc.py

@@ -38,6 +38,7 @@ from typing import (
     Protocol,
     Type,
     TypeVar,
+    Union,
 )
 
 import msgspec
@@ -46,9 +47,8 @@ import trio
 
 from tractor.log import get_logger
 from tractor._exceptions import (
-    MsgTypeError,
-    pack_from_raise,
     TransportClosed,
+    MsgTypeError,
 )
 from tractor.msg import (
     _ctxvar_MsgCodec,
@@ -118,24 +118,17 @@ class MsgTransport(Protocol[MsgType]):
         ...
 
 
-def _mk_msg_type_err(
+def _raise_msg_type_err(
     msg: Any|bytes,
     codec: MsgCodec,
-
+    validation_err: msgspec.ValidationError|None = None,
-    message: str|None = None,
     verb_header: str = '',
 
-    src_validation_error: msgspec.ValidationError|None = None,
+) -> None:
-    src_type_error: TypeError|None = None,
 
-) -> MsgTypeError:
+    # if side == 'send':
+    if validation_err is None:  # send-side
 
-    # `Channel.send()` case
-    if src_validation_error is None:  # send-side
-
-        # no src error from `msgspec.msgpack.Decoder.decode()` so
-        # prolly a manual type-check on our part.
-        if message is None:
         import traceback
         from tractor._exceptions import pformat_boxed_tb
 
@@ -151,42 +144,14 @@ def _mk_msg_type_err(
             field_prefix='  ',
             indent='',
         )
-            message: str = (
+        raise MsgTypeError(
             f'invalid msg -> {msg}: {type(msg)}\n\n'
             f'{tb_fmt}\n'
             f'Valid IPC msgs are:\n\n'
             # f'  ------ - ------\n'
-                f'{fmt_spec}\n',
+            f'{fmt_spec}\n'
-            )
-        elif src_type_error:
-            src_message: str = str(src_type_error)
-            patt: str = 'type '
-            type_idx: int = src_message.find('type ')
-            invalid_type: str = src_message[type_idx + len(patt):].split()[0]
-
-            enc_hook: Callable|None = codec.enc.enc_hook
-            if enc_hook is None:
-                message += (
-                    '\n\n'
-
-                    f"The current IPC-msg codec can't encode type `{invalid_type}` !\n"
-                    f'Maybe a `msgpack.Encoder.enc_hook()` extension is needed?\n\n'
-
-                    f'Check the `msgspec` docs for ad-hoc type extending:\n'
-                    '|_ https://jcristharif.com/msgspec/extending.html\n'
-                    '|_ https://jcristharif.com/msgspec/extending.html#defining-a-custom-extension-messagepack-only\n'
         )
 
-
-        msgtyperr = MsgTypeError(
-            message=message,
-            ipc_msg=msg,
-        )
-        # ya, might be `None`
-        msgtyperr.__cause__ = src_type_error
-        return msgtyperr
-
-    # `Channel.recv()` case
     else:
         # decode the msg-bytes using the std msgpack
         # interchange-prot (i.e. without any
@@ -196,31 +161,29 @@ def _mk_msg_type_err(
         msg_dict: dict = msgspec.msgpack.decode(msg)
         msg_type_name: str = msg_dict['msg_type']
         msg_type = getattr(msgtypes, msg_type_name)
-        message: str = (
+        errmsg: str = (
             f'invalid `{msg_type_name}` IPC msg\n\n'
         )
         if verb_header:
-            message = f'{verb_header} ' + message
+            errmsg = f'{verb_header} ' + errmsg
 
         # XXX see if we can determine the exact invalid field
         # such that we can comprehensively report the
         # specific field's type problem
-        msgspec_msg: str = src_validation_error.args[0].rstrip('`')
+        msgspec_msg: str = validation_err.args[0].rstrip('`')
         msg, _, maybe_field = msgspec_msg.rpartition('$.')
         obj = object()
         if (field_val := msg_dict.get(maybe_field, obj)) is not obj:
-            message += (
+            field_type: Union[Type] = msg_type.__signature__.parameters[
+                maybe_field
+            ].annotation
+            errmsg += (
                 f'{msg.rstrip("`")}\n\n'
                 f'{msg_type}\n'
-                f' |_.{maybe_field}: {codec.pld_spec_str} = {field_val!r}\n'
+                f' |_.{maybe_field}: {field_type} = {field_val!r}\n'
             )
 
-        msgtyperr = MsgTypeError.from_decode(
+        raise MsgTypeError(errmsg) from validation_err
-            message=message,
-            msgdict=msg_dict,
-        )
-        msgtyperr.__cause__ = src_validation_error
-        return msgtyperr
 
 
 # TODO: not sure why we have to inherit here, but it seems to be an
@@ -362,15 +325,12 @@ class MsgpackTCPStream(MsgTransport):
             # and always raise such that spec violations
             # are never allowed to be caught silently!
             except msgspec.ValidationError as verr:
-                msgtyperr: MsgTypeError = _mk_msg_type_err(
+                # re-raise as type error
+                _raise_msg_type_err(
                     msg=msg_bytes,
                     codec=codec,
-                    src_validation_error=verr,
+                    validation_err=verr,
                 )
-                # XXX deliver up to `Channel.recv()` where
-                # a re-raise and `Error`-pack can inject the far
-                # end actor `.uid`.
-                yield msgtyperr
 
             except (
                 msgspec.DecodeError,
@@ -427,7 +387,7 @@ class MsgpackTCPStream(MsgTransport):
 
             if type(msg) not in msgtypes.__msg_types__:
                 if strict_types:
-                    raise _mk_msg_type_err(
+                    _raise_msg_type_err(
                         msg,
                         codec=codec,
                     )
@@ -440,16 +400,11 @@ class MsgpackTCPStream(MsgTransport):
             try:
                 bytes_data: bytes = codec.encode(msg)
             except TypeError as typerr:
-                msgtyperr: MsgTypeError = _mk_msg_type_err(
+                raise MsgTypeError(
-                    msg,
+                    'A msg field violates the current spec\n'
-                    codec=codec,
+                    f'{codec.pld_spec}\n\n'
-                    message=(
-                        f'IPC-msg-spec violation in\n\n'
                     f'{pretty_struct.Struct.pformat(msg)}'
-                    ),
+                ) from typerr
-                    src_type_error=typerr,
-                )
-                raise msgtyperr from typerr
 
             # supposedly the fastest says,
             # https://stackoverflow.com/a/54027962
@@ -764,35 +719,13 @@ class Channel:
         assert self._transport
         while True:
             try:
-                async for msg in self._transport:
+                async for item in self._transport:
-                    match msg:
+                    yield item
-                        # NOTE: if transport/interchange delivers
-                        # a type error, we pack it with the far
-                        # end peer `Actor.uid` and relay the
-                        # `Error`-msg upward to the `._rpc` stack
-                        # for normal RAE handling.
-                        case MsgTypeError():
-                            yield pack_from_raise(
-                                local_err=msg,
-                                cid=msg.cid,
-
-                                # XXX we pack it here bc lower
-                                # layers have no notion of an
-                                # actor-id ;)
-                                src_uid=self.uid,
-                            )
-                        case _:
-                            yield msg
-
-                    # TODO: if we were gonna do this it should be
-                    # done up at the `MsgStream` layer!
-                    #
                     # sent = yield item
                     # if sent is not None:
                     #     # optimization, passing None through all the
                     #     # time is pointless
                     #     await self._transport.send(sent)
-
             except trio.BrokenResourceError:
 
                 # if not self._autorecon:

tractor/_portal.py

@@ -46,7 +46,6 @@ from ._state import (
 from ._ipc import Channel
 from .log import get_logger
 from .msg import (
-    Error,
     NamespacePath,
     Return,
 )
@@ -70,7 +69,8 @@ log = get_logger(__name__)
 # `._raise_from_no_key_in_msg()` (after tweak to
 # accept a `chan: Channel` arg) in key block!
 def _unwrap_msg(
-    msg: Return|Error,
+    # msg: dict[str, Any],
+    msg: Return,
     channel: Channel,
 
     hide_tb: bool = True,

tractor/_rpc.py

@@ -47,13 +47,12 @@ from ._context import (
     Context,
 )
 from ._exceptions import (
-    ContextCancelled,
     ModuleNotExposed,
-    MsgTypeError,
-    TransportClosed,
     is_multi_cancelled,
+    ContextCancelled,
     pack_error,
     unpack_error,
+    TransportClosed,
 )
 from .devx import (
     maybe_wait_for_debugger,
@@ -637,7 +636,7 @@ async def _invoke(
                     # (callee) task, so relay this cancel signal to the
                     # other side.
                     ctxc = ContextCancelled(
-                        message=msg,
+                        msg,
                         boxed_type=trio.Cancelled,
                         canceller=canceller,
                     )
@@ -827,12 +826,7 @@ async def process_messages(
                         | Stop(cid=cid)
                         | Return(cid=cid)
                         | CancelAck(cid=cid)
-
+                        | Error(cid=cid)  # RPC-task ctx specific
-                        # `.cid` means RPC-ctx-task specific
-                        | Error(cid=cid)
-
-                        # recv-side `MsgType` decode violation
-                        | MsgTypeError(cid=cid)
                     ):
                         # deliver response to local caller/waiter
                         # via its per-remote-context memory channel.

tractor/_runtime.py

@@ -49,6 +49,7 @@ from pprint import pformat
 import signal
 import sys
 from typing import (
+    Any,
     Callable,
     TYPE_CHECKING,
 )

tractor/msg/__init__.py

@@ -19,6 +19,7 @@ Built-in messaging patterns, types, APIs and helpers.
 
 '''
 from typing import (
+    Union,
     TypeAlias,
 )
 from .ptr import (
@@ -55,9 +56,8 @@ from .types import (
 
     # full msg class set from above as list
     __msg_types__ as __msg_types__,
-
-    # type-alias for union of all msgs
-    MsgType as MsgType,
 )
-
+# TODO: use new type declaration syntax for msg-type-spec
-__msg_spec__: TypeAlias = MsgType
+# https://docs.python.org/3/library/typing.html#type-aliases
+# https://docs.python.org/3/reference/simple_stmts.html#type
+__msg_spec__: TypeAlias = Union[*__msg_types__]

tractor/msg/_codec.py

@@ -57,7 +57,7 @@ from trio.lowlevel import (
 from tractor.msg.pretty_struct import Struct
 from tractor.msg.types import (
     mk_msg_spec,
-    MsgType,
+    Msg,
 )
 
 
@@ -87,50 +87,12 @@ class MsgCodec(Struct):
 
     pld_spec: Union[Type[Struct]]|None
 
-    @property
-    def pld_spec_str(self) -> str:
-        spec: Union[Type]|Type = self.pld_spec
-
-        # TODO: could also use match: instead?
-        if getattr(spec, '__args__', False):
-            # `typing.Union` case
-            return str(spec)
-        else:
-            return spec.__name__
-
     # struct type unions
     # https://jcristharif.com/msgspec/structs.html#tagged-unions
     @property
     def msg_spec(self) -> Union[Type[Struct]]:
         return self._dec.type
 
-    def msg_spec_items(
-        self,
-        msg: MsgType|None = None,
-
-    ) -> dict[str, MsgType]|str:
-
-        msgt_table: dict[str, MsgType] = {
-            msgt: str(msgt)
-            for msgt in self.msg_spec.__args__
-        }
-        if msg:
-            msgt: MsgType = type(msg)
-            str_repr: str = msgt_table[msgt]
-            return {msgt: str_repr}
-
-        return msgt_table
-
-    # TODO: some way to make `pretty_struct.Struct` use this
-    # wrapped field over the `.msg_spec` one?
-    def pformat_msg_spec(
-        self,
-        msg: MsgType|None = None,
-    ) -> str:
-        return '\n'.join(
-            self.msg_spec_items(msg=msg).values()
-        )
-
     lib: ModuleType = msgspec
 
     # TODO: a sub-decoder system as well?
@@ -146,7 +108,7 @@ class MsgCodec(Struct):
     # OR
     # ) = {
     #     # pre-seed decoders for std-py-type-set for use when
-    #     # `MsgType.pld == None|Any`.
+    #     # `Msg.pld == None|Any`.
     #     None: msgpack.Decoder(Any),
     #     Any: msgpack.Decoder(Any),
     # }
@@ -341,7 +303,7 @@ def mk_codec(
     # by `tag_field: str` value key?
     # payload_msg_specs: dict[
     #     str,  # tag_field value as sub-decoder key
-    #     Union[Type[Struct]]  # `MsgType.pld` type spec
+    #     Union[Type[Struct]]  # `Msg.pld` type spec
     # ]|None = None,
 
     libname: str = 'msgspec',
@@ -374,7 +336,7 @@ def mk_codec(
         raise RuntimeError(
             f'If a payload spec is provided,\n'
             "the builtin SC-shuttle-protocol's msg set\n"
-            f'(i.e. a `{MsgType}`) MUST be used!\n\n'
+            f'(i.e. `{Msg}`) MUST be used!\n\n'
             f'However both values were passed as => mk_codec(\n'
             f'   ipc_msg_spec={ipc_msg_spec}`\n'
             f'   ipc_pld_spec={ipc_pld_spec}`\n)\n'

tractor/msg/types.py

@@ -31,7 +31,6 @@ from typing import (
     Literal,
     Type,
     TypeVar,
-    TypeAlias,
     Union,
 )
 
@@ -401,29 +400,16 @@ class CancelAck(
     pld: bool
 
 
-# TODO: unify this with `._exceptions.RemoteActorError`
-# such that we can have a msg which is both raisable and
-# IPC-wire ready?
-# B~o
 class Error(
     Struct,
     tag=True,
     tag_field='msg_type',
-
-    # TODO may omit defaults?
-    # https://jcristharif.com/msgspec/structs.html#omitting-default-values
-    # omit_defaults=True,
 ):
     '''
     A pkt that wraps `RemoteActorError`s for relay and raising.
 
     Fields are 1-to-1 meta-data as needed originally by
-    `RemoteActorError.msgdata: dict` but now are defined here.
+    `RemoteActorError.msgdata: dict`.
-
-    Note: this msg shuttles `ContextCancelled` and `StreamOverrun`
-    as well is used to rewrap any `MsgTypeError` for relay-reponse
-    to bad `Yield.pld` senders during an IPC ctx's streaming dialog
-    phase.
 
     '''
     src_uid: tuple[str, str]
@@ -442,10 +428,6 @@ class Error(
     # `StreamOverrun`
     sender: tuple[str, str]|None = None
 
-    # for the `MsgTypeError` case where the receiver side
-    # decodes the underlying original `Msg`-subtype
-    _msg_dict: dict|None = None
-
 
 # TODO: should be make a msg version of `ContextCancelled?`
 # and/or with a scope field or a full `ActorCancelled`?
@@ -504,11 +486,6 @@ __msg_types__: list[Msg] = (
     _payload_msgs
 )
 
-# TODO: use new type declaration syntax for msg-type-spec
-# https://docs.python.org/3/library/typing.html#type-aliases
-# https://docs.python.org/3/reference/simple_stmts.html#type
-MsgType: TypeAlias = Union[*__msg_types__]
-
 
 def mk_msg_spec(
     payload_type_union: Union[Type] = Any,