constant: Add SpinValue

SpinValue acts as a type definition for values to and from Spin Devices

stspin/constants/__init__.py

@@ -1,5 +1,10 @@
 from .command import Command
-from .constant import Constant
+
+from .constant import (
+    Constant,
+    SpinValue,
+)
+
 from .register import Register
 
 from .status import (

stspin/constants/constant.py

@@ -3,6 +3,40 @@
 )
 
 
+class SpinValue:
+    """Class representing values sent to and from Spin Devices
+    :Value: Exclusively unsigned integers representing one or more bytes
+
+    """
+    Value: Final[int]
+    Type: Final = 'SpinValue'
+
+    def __init__(self, value: int) -> None:
+        assert(value >= 0)
+        self.Value = value
+
+    def __eq__(self, other: object) -> bool:
+        if isinstance(other, int):
+            return self.Value == other
+
+        if not isinstance(other, SpinValue):
+            return NotImplemented
+
+        return self.Value == other.Value
+
+    def __or__(self, other: object) -> object:
+        if isinstance(other, int):
+            return SpinValue(self.Value | other)
+
+        if not isinstance(other, SpinValue):
+            return NotImplemented
+
+        return SpinValue(self.Value | other.Value)
+
+    def __repr__(self) -> str:
+        return f'{self.Value}'
+
+
 class Constant:
     DirReverse: Final           = 0
     DirForward: Final           = 1