typing in progress, stuck on mutability of generic

pysemigroup/types.py

+from typing import (
+    Callable,
+    ClassVar,
+    Generic,
+    Hashable,
+    Iterable,
+    Iterator,
+    Mapping,
+    Optional,
+    Self,
+    Tuple,
+    TypeAlias,
+    TypeVar,
+    overload,
+)
+ViewEl = TypeVar("ViewEl", bound=Hashable)
+State = TypeVar("State", bound=Hashable)
+StateAlt = TypeVar("StateAlt", bound=Hashable)
+Symbol = TypeVar("Symbol", bound=Hashable)
+SymbolAlt = TypeVar("SymbolAlt", bound=Hashable)
+Transition: TypeAlias[State, Symbol] = Tuple[State, Symbol, State]
+MarkerVar = TypeVar("MarkerVar", bound=Hashable)

pysemigroup/views.py

@@ -4,9 +4,9 @@ from typing import (
     Iterator,
     Self,
 )
+from pysemigroup.types import ViewEl, State, Symbol
 
-
-class View(frozenset):
+class View(frozenset[ViewEl]):
     def __repr__(self):
         return f"{self.__class__.__name__}({self.subrepr()})"
 
@@ -25,15 +25,15 @@ class View(frozenset):
             yield type(self)(S.union((el,)))
 
 
-class StateView(View):
+class StateView(View[State]):
     ...
 
 
-class Configuration(View):
+class Configuration(View[State]):
     ...
 
 
-class AlphabetView(View):
+class AlphabetView(View[Symbol]):
     def compute_salt(self, retry=4):
         salt = random.randint(0, MAX_INT)
         S = set(map(lambda e: hash((e, salt)), self))