Merge branch 'argkinds' of https://github.com/BobTheBuidler/mypy into argkinds

Author: BobTheBuidler

mypy/nodes.py

@@ -2210,12 +2210,20 @@ def is_star(self) -> bool:
 @mypyc_attr(native_class=False)
 class ArgKinds(list[ArgKind]):
     def __init__(self, values: Iterable[ArgKind] = None) -> None:
+        if values is None:
+            super().__init__()
+        else:
+            super().__init__(values)
         self.__count_cache: dict[ArgKind, int] = {}
         self.__index_cache: dict[ArgKind, int] = {}
+        self.__positional_only: bool | None = None
 
     @property
     def positional_only(self) -> bool:
-        return all(kind == ARG_POS for kind in self)
+        pos_only = self.__positional_only
+        if pos_only is None:
+            pos_only = self.__positional_only = all(kind == ARG_POS for kind in self)
+        return pos_only
 
     @property
     def has_star(self) -> bool:

mypy/types.py

@@ -1917,7 +1917,11 @@ def __init__(
         self.arg_types = list(arg_types)
         self.arg_kinds = arg_kinds
         self.arg_names = list(arg_names)
-        assert len(arg_types) == len(arg_kinds) == len(arg_names), (len(arg_types), len(arg_kinds), len(arg_names))
+        assert len(arg_types) == len(arg_kinds) == len(arg_names), (
+            len(arg_types),
+            len(arg_kinds),
+            len(arg_names),
+        )
         assert not any(isinstance(t, Parameters) for t in arg_types)
         self.min_args = arg_kinds.count(ARG_POS)
         self.is_ellipsis_args = is_ellipsis_args
@@ -2158,7 +2162,11 @@ def __init__(
         unpack_kwargs: bool = False,
     ) -> None:
         super().__init__(line, column)
-        assert len(arg_types) == len(arg_kinds) == len(arg_names), (len(arg_types), len(arg_kinds), len(arg_names))
+        assert len(arg_types) == len(arg_kinds) == len(arg_names), (
+            len(arg_types),
+            len(arg_kinds),
+            len(arg_names),
+        )
         self.arg_types = list(arg_types)
         for t in self.arg_types:
             if isinstance(t, ParamSpecType):