Fix generic substitution for methods

trans/transpiler/phases/typing/types.py

@@ -46,7 +46,7 @@ class BaseType(ABC):
     # def clone(self) -> "BaseType":
     #     pass
 
-    def gen_sub(self, this: "BaseType", typevars: Dict[str, "BaseType"]) -> "Self":
+    def gen_sub(self, this: "BaseType", typevars: Dict[str, "BaseType"], cache=None) -> "Self":
         return self
 
     def to_list(self) -> List["BaseType"]:
@@ -104,7 +104,7 @@ class TypeVariable(BaseType):
     def contains_internal(self, other: BaseType) -> bool:
         return self.resolve() is other.resolve()
 
-    def gen_sub(self, this: "BaseType", typevars) -> "Self":
+    def gen_sub(self, this: "BaseType", typevars, cache=None) -> "Self":
         if match := typevars.get(self.name):
             return match
         return self
@@ -193,17 +193,22 @@ class TypeOperator(BaseType, ABC):
     def __hash__(self):
         return hash((self.name, tuple(self.args)))
 
-    def gen_sub(self, this: BaseType, typevars) -> "Self":
+    def gen_sub(self, this: BaseType, typevars, cache=None) -> "Self":
+        cache = cache or {}
+        if me := cache.get(self):
+            return me
         if len(self.args) == 0:
             return self
         res = object.__new__(self.__class__)  # todo: ugly... should make a clone()
+        cache[self] = res
         if isinstance(this, TypeOperator):
             vardict = dict(zip(typevars.keys(), this.args))
         else:
             vardict = typevars
         for k in dataclasses.fields(self):
             setattr(res, k.name, getattr(self, k.name))
-        res.args = [arg.resolve().gen_sub(this, vardict) for arg in self.args]
+        res.args = [arg.resolve().gen_sub(this, vardict, cache) for arg in self.args]
+        res.methods = {k: v.gen_sub(this, vardict, cache) for k, v in self.methods.items()}
         return res
 
     def to_list(self) -> List["BaseType"]:
@@ -269,7 +274,7 @@ TY_NONE = TypeOperator([], "NoneType")
 TY_MODULE = TypeOperator([], "module")
 TY_VARARG = TypeOperator([], "vararg")
 TY_SELF = TypeOperator([], "Self")
-TY_SELF.gen_sub = lambda this, typevars: this
+TY_SELF.gen_sub = lambda this, typevars, _: this
 
 
 class PyList(TypeOperator):