Add DType union to replace DATATYPE_DTYPES

In future, this should be used in place of DType_T in non-generic
contexts and DType_T should be bound to DType, but attempting this
revealed some exsiting typing problems that were difficult to resolve.

Remove incorrect Table dtype definition. It is actually just ndarray
like Waveform.

Author: GDYendell

src/fastcs/attributes/attribute.py

@@ -2,7 +2,7 @@
 from typing import Generic
 
 from fastcs.attributes.attribute_io_ref import AttributeIORefT
-from fastcs.datatypes import DATATYPE_DTYPES, DataType, DType_T
+from fastcs.datatypes import DataType, DType, DType_T
 from fastcs.logging import bind_logger
 from fastcs.tracer import Tracer
 
@@ -24,9 +24,8 @@ def __init__(
     ) -> None:
         super().__init__()
 
-        assert issubclass(datatype.dtype, DATATYPE_DTYPES), (
-            f"Attr type must be one of {DATATYPE_DTYPES}, "
-            "received type {datatype.dtype}"
+        assert issubclass(datatype.dtype, DType), (
+            f"Attr type must be one of {DType}, received type {datatype.dtype}"
         )
         self._io_ref = io_ref
         self._datatype: DataType[DType_T] = datatype

src/fastcs/datatypes/__init__.py

@@ -1,7 +1,7 @@
 from ._util import numpy_to_fastcs_datatype as numpy_to_fastcs_datatype
 from .bool import Bool as Bool
-from .datatype import DATATYPE_DTYPES as DATATYPE_DTYPES
 from .datatype import DataType as DataType
+from .datatype import DType as DType
 from .datatype import DType_T as DType_T
 from .enum import Enum as Enum
 from .float import Float as Float

src/fastcs/datatypes/datatype.py

@@ -4,7 +4,15 @@
 from typing import Any, Generic, TypeVar
 
 import numpy as np
-from numpy.typing import DTypeLike
+
+DType = (
+    int  # Int
+    | float  # Float
+    | bool  # Bool
+    | str  # String
+    | enum.Enum  # Enum
+    | np.ndarray  # Waveform / Table
+)
 
 DType_T = TypeVar(
     "DType_T",
@@ -13,13 +21,10 @@
     bool,  # Bool
     str,  # String
     enum.Enum,  # Enum
-    np.ndarray,  # Waveform
-    list[tuple[str, DTypeLike]],  # Table
+    np.ndarray,  # Waveform / Table
 )
 """A builtin (or numpy) type supported by a corresponding FastCS Attribute DataType"""
 
-DATATYPE_DTYPES: tuple[type] = DType_T.__constraints__  # type: ignore
-
 
 @dataclass(frozen=True)
 class DataType(Generic[DType_T]):