Change bound tp params to always be non

Author: saulshanabrook

python/egglog/declarations.py

@@ -639,7 +639,7 @@ class CallDecl:
     args: tuple[TypedExprDecl, ...] = ()
     # type parameters that were bound to the callable, if it is a classmethod
     # Used for pretty printing classmethod calls with type parameters
-    bound_tp_params: tuple[JustTypeRef, ...] | None = None
+    bound_tp_params: tuple[JustTypeRef, ...] = ()
 
     # pool objects for faster __eq__
     _args_to_value: ClassVar[WeakValueDictionary[tuple[object, ...], CallDecl]] = WeakValueDictionary({})
@@ -654,7 +654,7 @@ def __new__(cls, *args: object, **kwargs: object) -> Self:
         # normalize the args/kwargs to a tuple so that they can be compared
         callable = args[0] if args else kwargs["callable"]
         args_ = args[1] if len(args) > 1 else kwargs.get("args", ())
-        bound_tp_params = args[2] if len(args) > 2 else kwargs.get("bound_tp_params")
+        bound_tp_params = args[2] if len(args) > 2 else kwargs.get("bound_tp_params", ())
 
         normalized_args = (callable, args_, bound_tp_params)
         try:

python/egglog/egraph_state.py

@@ -793,7 +793,7 @@ def from_call(
                     args,
                     # Don't include bound type params if this is just a method, we only needed them for type resolution
                     # but dont need to store them
-                    bound_tp_params if isinstance(callable_ref, ClassMethodRef | InitRef) else None,
+                    bound_tp_params if isinstance(callable_ref, ClassMethodRef | InitRef) else (),
                 )
         raise ValueError(
             f"Could not find callable ref for call {term}. None of these refs matched the types: {self.state.egg_fn_to_callable_refs[term.name]}"

python/egglog/runtime.py

@@ -457,7 +457,7 @@ def __call__(self, *args: object, _egg_partial_function: bool = False, **kwargs:
         arg_exprs = tuple(arg.__egg_typed_expr__ for arg in upcasted_args)
         return_tp = tcs.substitute_typevars(signature.semantic_return_type, cls_name)
         bound_params = (
-            cast("JustTypeRef", bound_tp).args if isinstance(self.__egg_ref__, ClassMethodRef | InitRef) else None
+            cast("JustTypeRef", bound_tp).args if isinstance(self.__egg_ref__, ClassMethodRef | InitRef) else ()
         )
         # If we were using unstable-app to call a funciton, add that function back as the first arg.
         if function_value:

python/egglog/type_constraint_solver.py

@@ -54,7 +54,7 @@ def infer_arg_types(
         fn_var_args: TypeOrVarRef | None,
         return_: JustTypeRef,
         cls_name: str | None,
-    ) -> tuple[Iterable[JustTypeRef], tuple[JustTypeRef, ...] | None]:
+    ) -> tuple[Iterable[JustTypeRef], tuple[JustTypeRef, ...]]:
         """
         Given a return type, infer the argument types. If there is a variable arg, it returns an infinite iterable.
 
@@ -75,7 +75,7 @@ def infer_arg_types(
                 )
             )
             if cls_name
-            else None
+            else ()
         )
         return arg_types, bound_typevars