feat(api): support selectors in window function order_by and group_by

ibis/common/selectors.py

@@ -0,0 +1,31 @@
+from __future__ import annotations
+
+import abc
+from typing import TYPE_CHECKING
+
+from ibis.common.grounds import Concrete
+
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
+    import ibis.expr.types as ir
+
+
+class Selector(Concrete):
+    """A column selector."""
+
+    @abc.abstractmethod
+    def expand(self, table: ir.Table) -> Sequence[ir.Value]:
+        """Expand `table` into value expressions that match the selector.
+
+        Parameters
+        ----------
+        table
+            An ibis table expression
+
+        Returns
+        -------
+        Sequence[Value]
+            A sequence of value expressions that match the selector
+
+        """

ibis/expr/builders.py

@@ -13,6 +13,7 @@
 from ibis.common.deferred import Deferred, Resolver, deferrable
 from ibis.common.exceptions import IbisInputError
 from ibis.common.grounds import Concrete
+from ibis.common.selectors import Selector  # noqa: TCH001
 from ibis.common.typing import VarTuple  # noqa: TCH001
 
 if TYPE_CHECKING:
@@ -145,8 +146,8 @@ class WindowBuilder(Builder):
     how: Literal["rows", "range"] = "rows"
     start: Optional[RangeWindowBoundary] = None
     end: Optional[RangeWindowBoundary] = None
-    groupings: VarTuple[Union[str, Resolver, ops.Value]] = ()
-    orderings: VarTuple[Union[str, Resolver, ops.SortKey]] = ()
+    groupings: VarTuple[Union[str, Resolver, Selector, ops.Value]] = ()
+    orderings: VarTuple[Union[str, Resolver, Selector, ops.SortKey]] = ()
 
     @attribute
     def _table(self):

ibis/expr/types/relations.py

@@ -18,12 +18,12 @@
 import ibis.expr.schema as sch
 from ibis import util
 from ibis.common.deferred import Deferred, Resolver
+from ibis.common.selectors import Selector
 from ibis.expr.rewrites import DerefMap
 from ibis.expr.types.core import Expr, _FixedTextJupyterMixin
 from ibis.expr.types.generic import Value, literal
 from ibis.expr.types.pretty import to_rich
 from ibis.expr.types.temporal import TimestampColumn
-from ibis.selectors import Selector
 from ibis.util import deprecated
 
 if TYPE_CHECKING:

ibis/selectors.py

@@ -50,7 +50,6 @@
 
 from __future__ import annotations
 
-import abc
 import functools
 import inspect
 import operator
@@ -67,27 +66,8 @@
 from ibis.common.collections import frozendict  # noqa: TCH001
 from ibis.common.deferred import Deferred, Resolver
 from ibis.common.exceptions import IbisError
-from ibis.common.grounds import Concrete, Singleton
-
-
-class Selector(Concrete):
-    """A column selector."""
-
-    @abc.abstractmethod
-    def expand(self, table: ir.Table) -> Sequence[ir.Value]:
-        """Expand `table` into value expressions that match the selector.
-
-        Parameters
-        ----------
-        table
-            An ibis table expression
-
-        Returns
-        -------
-        Sequence[Value]
-            A sequence of value expressions that match the selector
-
-        """
+from ibis.common.grounds import Singleton
+from ibis.common.selectors import Selector
 
 
 class Predicate(Selector):

ibis/tests/expr/test_selectors.py

@@ -494,3 +494,26 @@ def test_order_by_with_selectors(penguins):
 
     with pytest.raises(exc.IbisError):
         penguins.order_by(~s.all())
+
+
+def test_window_function_group_by(penguins):
+    expr = penguins.species.count().over(group_by=s.c("island"))
+    assert expr.equals(penguins.species.count().over(group_by=penguins.island))
+
+
+def test_window_function_order_by(penguins):
+    expr = penguins.island.count().over(order_by=s.c("species"))
+    assert expr.equals(penguins.island.count().over(order_by=penguins.species))
+
+
+def test_window_function_group_by_order_by(penguins):
+    expr = penguins.species.count().over(
+        group_by=s.c("island"),
+        order_by=s.c("year") | (~s.c("island", "species") & s.of_type("str")),
+    )
+    assert expr.equals(
+        penguins.species.count().over(
+            group_by=penguins.island,
+            order_by=[penguins.sex, penguins.year],
+        )
+    )