Tweak some `pformat_boxed_tb()` indent inputs

- add some `tb_str: str` indent-prefix args for diff indent levels for the
body vs. the surrounding "ascii box".
- ^-use it-^ from `RemoteActorError.__repr()__` obvi.
- use new `msg.types.from_dict_msg()` in impl of
  `MsgTypeError.payload_msg`, handy for showing what the message "would
  have looked like in `Struct` form" had it not failed it's type
  constraints.

tractor/_exceptions.py

@@ -40,7 +40,7 @@ from tractor._state import current_actor
 from tractor.log import get_logger
 from tractor.msg import (
     Error,
-    Msg,
+    MsgType,
     Stop,
     Yield,
     pretty_struct,
@@ -130,7 +130,10 @@ def pformat_boxed_tb(
     tb_str: str,
     fields_str: str|None = None,
     field_prefix: str = ' |_',
-    indent: str = ' '*2
+
+    tb_box_indent: int|None = None,
+    tb_body_indent: int = 1,
+
 ) -> str:
     if (
         fields_str
@@ -139,15 +142,19 @@ def pformat_boxed_tb(
     ):
         fields: str = textwrap.indent(
             fields_str,
-            # prefix=' '*2,
-            # prefix=' |_',
             prefix=field_prefix,
         )
     else:
         fields = fields_str or ''
 
-    # body_indent: str = len(field_prefix) * ' '
+    tb_body = tb_str
-    body: str = (
+    if tb_body_indent:
+        tb_body: str = textwrap.indent(
+            tb_str,
+            prefix=tb_body_indent * ' ',
+        )
+
+    tb_box: str = (
 
         # orig
         # f'  |\n'
@@ -158,21 +165,29 @@ def pformat_boxed_tb(
 
         f'|\n'
         f' ------ - ------\n\n'
-        f'{tb_str}\n'
+        # f'{tb_str}\n'
+        f'{tb_body}'
         f'  ------ - ------\n'
         f'_|\n'
     )
-    if len(indent):
+    tb_box_indent: str = (
-        body: str = textwrap.indent(
+        tb_box_indent
-            body,
+        or
-            # prefix=body_indent,
+        1
-            prefix=indent,
+
+        # (len(field_prefix))
+        # ? ^-TODO-^ ? if you wanted another indent level
+    )
+    if tb_box_indent > 0:
+        tb_box: str = textwrap.indent(
+            tb_box,
+            prefix=tb_box_indent * ' ',
         )
 
     return (
         fields
         +
-        body
+        tb_box
     )
 
 
@@ -316,7 +331,7 @@ class RemoteActorError(Exception):
         if self._ipc_msg is None:
             return None
 
-        msg_type: Msg = type(self._ipc_msg)
+        msg_type: MsgType = type(self._ipc_msg)
         fields: dict[str, Any] = {
             k: v for _, k, v in
             pretty_struct.iter_fields(self._ipc_msg)
@@ -493,7 +508,10 @@ class RemoteActorError(Exception):
             tb_str=self.tb_str,
             fields_str=fields,
             field_prefix=' |_',
-            indent=' ',  # no indent?
+            # ^- is so that it's placed like so,
+            # just after <Type(
+            #             |___ ..
+            tb_body_indent=1,
         )
         return (
             f'<{type(self).__name__}(\n'
@@ -623,7 +641,7 @@ class MsgTypeError(
 
     '''
     reprol_fields: list[str] = [
-        'ipc_msg',
+        'payload_msg',
     ]
     extra_body_fields: list[str] = [
         'cid',
@@ -633,7 +651,7 @@ class MsgTypeError(
     @property
     def msg_dict(self) -> dict[str, Any]:
         '''
-        If the underlying IPC `Msg` was received from a remote
+        If the underlying IPC `MsgType` was received from a remote
         actor but was unable to be decoded to a native
         `Yield`|`Started`|`Return` struct, the interchange backend
         native format decoder can be used to stash a `dict`
@@ -643,22 +661,21 @@ class MsgTypeError(
         return self.msgdata.get('_msg_dict')
 
     @property
-    def payload_msg(self) -> Msg|None:
+    def payload_msg(
+        self,
+    ) -> MsgType|None:
         '''
         Attempt to construct what would have been the original
-        `Msg`-with-payload subtype (i.e. an instance from the set
+        `MsgType`-with-payload subtype (i.e. an instance from the set
         of msgs in `.msg.types._payload_msgs`) which failed
         validation.
 
         '''
-        msg_dict: dict = self.msg_dict.copy()
+        if msg_dict := self.msg_dict.copy():
-        name: str = msg_dict.pop('msg_type')
+            return msgtypes.from_dict_msg(
-        msg_type: Msg = getattr(
+                dict_msg=msg_dict,
-            msgtypes,
-            name,
-            Msg,
             )
-        return msg_type(**msg_dict)
+        return None
 
     @property
     def cid(self) -> str:
@@ -908,7 +925,7 @@ def is_multi_cancelled(exc: BaseException) -> bool:
 
 def _raise_from_no_key_in_msg(
     ctx: Context,
-    msg: Msg,
+    msg: MsgType,
     src_err: KeyError,
     log: StackLevelAdapter,  # caller specific `log` obj
 

tractor/msg/__init__.py

@@ -53,6 +53,9 @@ from .types import (
 
     Error as Error,
 
+    # type-var for `.pld` field
+    PayloadT as PayloadT,
+
     # full msg class set from above as list
     __msg_types__ as __msg_types__,
 

tractor/msg/_codec.py

@@ -37,6 +37,7 @@ from contextlib import (
 #     ContextVar,
 #     Token,
 # )
+import textwrap
 from typing import (
     Any,
     Callable,
@@ -59,7 +60,9 @@ from tractor.msg.types import (
     mk_msg_spec,
     MsgType,
 )
+from tractor.log import get_logger
 
+log = get_logger(__name__)
 
 # TODO: overall IPC msg-spec features (i.e. in this mod)!
 #
@@ -87,6 +90,27 @@ class MsgCodec(Struct):
 
     pld_spec: Union[Type[Struct]]|None
 
+    def __repr__(self) -> str:
+        speclines: str = textwrap.indent(
+            self.pformat_msg_spec(),
+            prefix=' '*3,
+        )
+        body: str = textwrap.indent(
+            f'|_lib = {self.lib.__name__!r}\n'
+            f'|_enc_hook: {self.enc.enc_hook}\n'
+            f'|_dec_hook: {self.dec.dec_hook}\n'
+            f'|_pld_spec: {self.pld_spec_str}\n'
+            # f'|\n'
+            f'|__msg_spec__:\n'
+            f'{speclines}\n',
+            prefix=' '*2,
+        )
+        return (
+            f'<{type(self).__name__}(\n'
+            f'{body}'
+            ')>'
+        )
+
     @property
     def pld_spec_str(self) -> str:
         spec: Union[Type]|Type = self.pld_spec
@@ -163,8 +187,8 @@ class MsgCodec(Struct):
 
     ) -> bytes:
         '''
-        Encode input python objects to `msgpack` bytes for transfer
+        Encode input python objects to `msgpack` bytes for
-        on a tranport protocol connection.
+        transfer on a tranport protocol connection.
 
         '''
         return self._enc.encode(py_obj)
@@ -325,15 +349,9 @@ class MsgCodec(Struct):
 
 
 def mk_codec(
-    ipc_msg_spec: Union[Type[Struct]]|Any|None = None,
-    #
-    # ^TODO^: in the long run, do we want to allow using a diff IPC `Msg`-set?
-    # it would break the runtime, but maybe say if you wanted
-    # to add some kinda field-specific or wholesale `.pld` ecryption?
-
     # struct type unions set for `Decoder`
     # https://jcristharif.com/msgspec/structs.html#tagged-unions
-    ipc_pld_spec: Union[Type[Struct]]|Any|None = None,
+    ipc_pld_spec: Union[Type[Struct]]|Any = Any,
 
     # TODO: offering a per-msg(-field) type-spec such that
     # the fields can be dynamically NOT decoded and left as `Raw`
@@ -352,7 +370,6 @@ def mk_codec(
     dec_hook: Callable|None = None,
     enc_hook: Callable|None = None,
     # ------ - ------
-    **kwargs,
     #
     # Encoder:
     # write_buffer_size=write_buffer_size,
@@ -367,28 +384,6 @@ def mk_codec(
     `msgspec` ;).
 
     '''
-    if (
-        ipc_msg_spec is not None
-        and ipc_pld_spec
-    ):
-        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'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'
-        )
-
-    elif (
-        ipc_pld_spec
-        and
-
-        # XXX required for now (or maybe forever?) until
-        # we can dream up a way to allow parameterizing and/or
-        # custom overrides to the `Msg`-spec protocol itself?
-        ipc_msg_spec is None
-    ):
     # (manually) generate a msg-payload-spec for all relevant
     # god-boxing-msg subtypes, parameterizing the `Msg.pld: PayloadT`
     # for the decoder such that all sub-type msgs in our SCIPP
@@ -403,9 +398,6 @@ def mk_codec(
     assert len(ipc_msg_spec.__args__) == len(msg_types)
     assert ipc_msg_spec
 
-    else:
-        ipc_msg_spec = ipc_msg_spec or Any
-
     enc = msgpack.Encoder(
        enc_hook=enc_hook,
     )
@@ -418,8 +410,6 @@ def mk_codec(
         _enc=enc,
         _dec=dec,
         pld_spec=ipc_pld_spec,
-        # payload_msg_specs=payload_msg_specs,
-        # **kwargs,
     )
 
     # sanity on expected backend support
@@ -500,8 +490,16 @@ def apply_codec(
     - https://github.com/oremanj/tricycle/blob/master/tricycle/_tests/test_tree_var.py
 
     '''
+    __tracebackhide__: bool = True
     orig: MsgCodec = _ctxvar_MsgCodec.get()
     assert orig is not codec
+    if codec.pld_spec is None:
+        breakpoint()
+
+    log.info(
+        'Applying new msg-spec codec\n\n'
+        f'{codec}\n'
+    )
     token: RunVarToken = _ctxvar_MsgCodec.set(codec)
 
     # TODO: for TreeVar approach, see docs for @cm `.being()` API:
@@ -518,7 +516,10 @@ def apply_codec(
         _ctxvar_MsgCodec.reset(token)
 
     assert _ctxvar_MsgCodec.get() is orig
-
+    log.info(
+        'Reverted to last msg-spec codec\n\n'
+        f'{orig}\n'
+    )
 
 def current_codec() -> MsgCodec:
     '''
@@ -532,14 +533,15 @@ def current_codec() -> MsgCodec:
 
 @cm
 def limit_msg_spec(
-    payload_types: Union[Type[Struct]],
+    payload_spec: Union[Type[Struct]],
 
     # TODO: don't need this approach right?
     # -> related to the `MsgCodec._payload_decs` stuff above..
     # tagged_structs: list[Struct]|None = None,
 
     **codec_kwargs,
-):
+
+) -> MsgCodec:
     '''
     Apply a `MsgCodec` that will natively decode the SC-msg set's
     `Msg.pld: Union[Type[Struct]]` payload fields using
@@ -547,10 +549,37 @@ def limit_msg_spec(
     for all IPC contexts in use by the current `trio.Task`.
 
     '''
+    __tracebackhide__: bool = True
+    curr_codec = current_codec()
     msgspec_codec: MsgCodec = mk_codec(
-        payload_types=payload_types,
+        ipc_pld_spec=payload_spec,
         **codec_kwargs,
     )
     with apply_codec(msgspec_codec) as applied_codec:
         assert applied_codec is msgspec_codec
         yield msgspec_codec
+
+    assert curr_codec is current_codec()
+
+
+# XXX: msgspec won't allow this with non-struct custom types
+# like `NamespacePath`!@!
+# @cm
+# def extend_msg_spec(
+#     payload_spec: Union[Type[Struct]],
+
+# ) -> MsgCodec:
+#     '''
+#     Extend the current `MsgCodec.pld_spec` (type set) by extending
+#     the payload spec to **include** the types specified by
+#     `payload_spec`.
+
+#     '''
+#     codec: MsgCodec = current_codec()
+#     pld_spec: Union[Type] = codec.pld_spec
+#     extended_spec: Union[Type] = pld_spec|payload_spec
+
+#     with limit_msg_spec(payload_types=extended_spec) as ext_codec:
+#         # import pdbp; pdbp.set_trace()
+#         assert ext_codec.pld_spec == extended_spec
+#         yield ext_codec

tractor/msg/pretty_struct.py

@@ -140,6 +140,7 @@ class Struct(
 
         return sin_props
 
+    # TODO: make thisi a mod-func!
     def pformat(
         self,
         field_indent: int = 2,

tractor/msg/types.py

@@ -447,6 +447,29 @@ class Error(
     _msg_dict: dict|None = None
 
 
+def from_dict_msg(
+    dict_msg: dict,
+
+    msgT: MsgType|None = None,
+    tag_field: str = 'msg_type'
+
+) -> MsgType:
+    '''
+    Helper to build a specific `MsgType` struct from
+    a "vanilla" decoded `dict`-ified equivalent of the
+    msg: i.e. if the `msgpack.Decoder.type == Any`.
+
+    '''
+    msg_type_tag_field: str = (
+        msgT.__struct_config__.tag_field
+        if msgT is not None
+        else tag_field
+    )
+    # XXX ensure tag field is removed
+    msgT_name: str = dict_msg.pop(msg_type_tag_field)
+    msgT: MsgType = _msg_table[msgT_name]
+    return msgT(**dict_msg)
+
 # TODO: should be make a msg version of `ContextCancelled?`
 # and/or with a scope field or a full `ActorCancelled`?
 # class Cancelled(Msg):
@@ -498,12 +521,18 @@ _payload_msgs: list[Msg] = [
 
 # built-in SC shuttle protocol msg type set in
 # approx order of the IPC txn-state spaces.
-__msg_types__: list[Msg] = (
+__msg_types__: list[MsgType] = (
     _runtime_msgs
     +
     _payload_msgs
 )
 
+
+_msg_table: dict[str, MsgType] = {
+    msgT.__name__: msgT
+    for msgT in __msg_types__
+}
+
 # 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
@@ -660,6 +689,11 @@ def mk_msg_spec(
         'Generating new IPC msg-spec\n'
         f'{ipc_spec}\n'
     )
+    assert (
+        ipc_spec
+        and
+        ipc_spec is not Any
+    )
     return (
         ipc_spec,
         msgtypes_table[spec_build_method] + ipc_msg_types,
@@ -679,88 +713,15 @@ def mk_msg_spec(
 #     manual convertion from our above native `Msg` set
 #     to `dict` equivalent (wire msgs) in order to keep legacy compat
 #     with the original runtime implementation.
-
+#
 #     Note: this is is/was primarly used while moving the core
 #     runtime over to using native `Msg`-struct types wherein we
 #     start with the send side emitting without loading
 #     a typed-decoder and then later flipping the switch over to
 #     load to the native struct types once all runtime usage has
 #     been adjusted appropriately.
-
+#
 #     '''
-#     def enc_to_dict(msg: Any) -> Any:
-#         '''
-#         Encode `Msg`-structs to `dict` msgs instead
-#         of using `msgspec.msgpack.Decoder.type`-ed
-#         features.
-
-#         '''
-#         match msg:
-#             case Start():
-#                 dctmsg: dict = pretty_struct.Struct.to_dict(
-#                     msg
-#                 )['pld']
-
-#             case Error():
-#                 dctmsg: dict = pretty_struct.Struct.to_dict(
-#                     msg
-#                 )['pld']
-#                 return {'error': dctmsg}
-
-
-#     def dec_from_dict(
-#         type: Type,
-#         obj: Any,
-#     ) -> Any:
-#         '''
-#         Decode to `Msg`-structs from `dict` msgs instead
-#         of using `msgspec.msgpack.Decoder.type`-ed
-#         features.
-
-#         '''
-#         cid: str = obj.get('cid')
-#         match obj:
-#             case {'cmd': pld}:
-#                 return Start(
-#                     cid=cid,
-#                     pld=pld,
-#                 )
-#             case {'functype': pld}:
-#                 return StartAck(
-#                     cid=cid,
-#                     functype=pld,
-#                     # pld=IpcCtxSpec(
-#                     #     functype=pld,
-#                     # ),
-#                 )
-#             case {'started': pld}:
-#                 return Started(
-#                     cid=cid,
-#                     pld=pld,
-#                 )
-#             case {'yield': pld}:
-#                 return Yield(
-#                     cid=obj['cid'],
-#                     pld=pld,
-#                 )
-#             case {'stop': pld}:
-#                 return Stop(
-#                     cid=cid,
-#                 )
-#             case {'return': pld}:
-#                 return Return(
-#                     cid=cid,
-#                     pld=pld,
-#                 )
-
-#             case {'error': pld}:
-#                 return Error(
-#                     cid=cid,
-#                     pld=ErrorData(
-#                         **pld
-#                     ),
-#                 )
-
 #     return (
 #         # enc_to_dict,
 #         dec_from_dict,