1 files changed, 85 insertions, 0 deletions
diff --git a/immutables/_protocols.py b/immutables/_protocols.py
new file mode 100644
index 0000000..de87d23
--- /dev/null
+++ b/immutables/_protocols.py
@@ -0,0 +1,85 @@
+import sys
+from typing import Any
+from typing import Hashable
+from typing import Iterable
+from typing import Iterator
+from typing import NoReturn
+from typing import Optional
+from typing import Tuple
+from typing import TypeVar
+from typing import Union
+from typing import overload
+
+if sys.version_info >= (3, 8):
+    from typing import Protocol
+    from typing import TYPE_CHECKING
+else:
+    from typing_extensions import Protocol
+    from typing_extensions import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from ._map import Map
+
+HT = TypeVar('HT', bound=Hashable)
+KT = TypeVar('KT', bound=Hashable)
+KT_co = TypeVar('KT_co', covariant=True)
+MM = TypeVar('MM', bound='MapMutation[Any, Any]')
+T = TypeVar('T')
+VT = TypeVar('VT')
+VT_co = TypeVar('VT_co', covariant=True)
+
+
+class MapKeys(Protocol[KT_co]):
+    def __len__(self) -> int: ...
+    def __iter__(self) -> Iterator[KT_co]: ...
+
+
+class MapValues(Protocol[VT_co]):
+    def __len__(self) -> int: ...
+    def __iter__(self) -> Iterator[VT_co]: ...
+
+
+class MapItems(Protocol[KT_co, VT_co]):
+    def __len__(self) -> int: ...
+    def __iter__(self) -> Iterator[Tuple[KT_co, VT_co]]: ...
+
+
+class IterableItems(Protocol[KT_co, VT_co]):
+    def items(self) -> Iterable[Tuple[KT_co, VT_co]]: ...
+
+
+class MapMutation(Protocol[KT, VT]):
+    def set(self, key: KT, val: VT) -> None: ...
+    def __enter__(self: MM) -> MM: ...
+    def __exit__(self, *exc: Any) -> bool: ...
+    def __iter__(self) -> NoReturn: ...
+    def __delitem__(self, key: KT) -> None: ...
+    def __setitem__(self, key: KT, val: VT) -> None: ...
+    @overload
+    def pop(self, __key: KT) -> VT: ...
+    @overload
+    def pop(self, __key: KT, __default: T) -> Union[VT, T]: ...
+    @overload
+    def get(self, key: KT) -> Optional[VT]: ...
+    @overload
+    def get(self, key: KT, default: Union[VT, T]) -> Union[VT, T]: ...
+    def __getitem__(self, key: KT) -> VT: ...
+    def __contains__(self, key: object) -> bool: ...
+
+    @overload
+    def update(
+        self,
+        __col: Union[IterableItems[KT, VT], Iterable[Tuple[KT, VT]]]
+    ) -> None: ...
+
+    @overload
+    def update(
+        self: 'MapMutation[Union[HT, str], Any]',
+        __col: Union[IterableItems[KT, VT], Iterable[Tuple[KT, VT]]],
+        **kw: VT
+    ) -> None: ...
+    @overload
+    def update(self: 'MapMutation[Union[HT, str], Any]', **kw: VT) -> None: ...
+    def finish(self) -> 'Map[KT, VT]': ...
+    def __len__(self) -> int: ...
+    def __eq__(self, other: Any) -> bool: ...