From 21384c3da92708760f7049beb1ae2258679e2fd1 Mon Sep 17 00:00:00 2001
From: Phillip Cloud <417981+cpcloud@users.noreply.github.com>
Date: Thu, 22 Feb 2024 11:25:12 -0500
Subject: [PATCH] chore: resurrect `SupportsSchema` type; clean up unused
 ignored imports (#8421)

---
 ibis/common/typing.py | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/ibis/common/typing.py b/ibis/common/typing.py
index 255939c96aad..5d4bca1d1678 100644
--- a/ibis/common/typing.py
+++ b/ibis/common/typing.py
@@ -4,25 +4,27 @@
 import sys
 from abc import abstractmethod
 from itertools import zip_longest
-from types import ModuleType  # noqa: F401
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    Generic,  # noqa: F401
-    Optional,
-    TypeVar,
-    Union,
-    get_args,
-    get_origin,
-)
+from typing import TYPE_CHECKING, Any, Optional, TypeVar, Union, get_args, get_origin
 from typing import get_type_hints as _get_type_hints
 
 from ibis.common.bases import Abstract
 from ibis.common.caching import memoize
 
 if TYPE_CHECKING:
+    from collections.abc import Iterable, Mapping
+
     from typing_extensions import Self
 
+    import ibis.expr.datatypes as dt
+    import ibis.expr.schema as sch
+
+    SupportsSchema = TypeVar(
+        "SupportsSchema",
+        sch.Schema,
+        Mapping[str, str | dt.DataType],
+        Iterable[tuple[str, str | dt.DataType]],
+    )
+
 if sys.version_info >= (3, 10):
     from types import UnionType
     from typing import TypeAlias
@@ -144,6 +146,7 @@ def get_bound_typevars(obj: Any) -> dict[TypeVar, tuple[str, type]]:
 
     Examples
     --------
+    >>> from typing import Generic
     >>> class MyStruct(Generic[T, U]):
     ...     a: T
     ...     b: U