To make nested `msgspec.Struct`s work we need to tell the codec that the
`.symbol` is some struct def, since we don't really need to enforce that
(yet) we're just going to enc/dec as `str` until we further formalize
and/or need something more complex.
Initial attempt at getting the sampling and shm layer to use the new mkt
info meta-data type. Draft out a potential `BackendInitMsg:
msgspec.Struct` for validating the init msg returned from the
`stream_quotes()` start value; obvs don't actually use it yet.
To be compat with the `Symbol` (for now) and generally allow for reading
the (derivative) contract specific part of the fqme. Adjust
`contract_info: list[str]` and make `src: str = ''` by default.
Add `MktPair` handling block for when a backend delivers
a `mkt_info`-field containing init msg. Adjust the original
`Symbol`-style `'symbol_info'` msg processing to do `Decimal` defaults
and convert to `MktPair` including slapping in a hacky `_atype: str`
field XD
General initial name changes to `bs_mktid` and `_fqme` throughout!
For `price_tick` and `size_tick` we read in `str` and decimal-ize
and now correctly fail over to default values of the same type..
Also, always treat `bs_mktid` field as a `str` in TOML form.
Drop the strange `clears: dict` var from the loading code (not sure why
that was left in smh) and better name `toml_clears_list` for the
TOML-loaded-pre-transaction sequence.
Handle case where `'dst'` field is just a `str` (in which case delegate to
`.from_fqme()`) as well as do `Asset` loading and use our
`Struct.copy()` to enforce type-casting to (for eg. `Decimal`s) such
that we'll now capture typing errors despite IPC transport.
Change `Symbol.tick_size` and `.lot_tick_size` defaults to decimal
for proper casting and type `MktPair.atype: str` since `msgspec` can't
cast to `AssetTypeName` without special handling..
Allows building a `MktPair` from the backend specific `Pair` for
eventual use in the data feed layer. Also adds `Pair.price/tick_size` to
get to the expected tick precision info format.
Add a logic branch for now that switches on an instance check.
Generally swap over all `Position.symbol` and `Transaction.sym` refs to
`MktPair`. Do a wholesale rename of all `.bsuid` var names to
`.bs_mktid`.
Instead let's name it `.sys` for "system", the thing we use to conduct
the "transactions" ..
Also rename `.bsuid` -> `.bs_mktid` for "backend system market id`
which is more explicit, easier to remember and read.