Add intersection operator, &, to ShapeList

src/build123d/topology.py

@@ -3650,6 +3650,10 @@ def __or__(self, filter_by: Union[Axis, GeomType] = Axis.Z):
         """Filter by axis or geomtype operator |"""
         return self.filter_by(filter_by)
 
+    def __eq__(self, other: ShapeList):
+        """ShapeLists equality operator =="""
+        return set(self) == set(other)
+
     def __add__(self, other: ShapeList):
         """Combine two ShapeLists together operator +"""
         return ShapeList(list(self) + list(other))
@@ -3661,6 +3665,10 @@ def __sub__(self, other: ShapeList) -> ShapeList:
         # return ShapeList(hash_set.values())
         return ShapeList(set(self) - set(other))
 
+    def __and__(self, other: ShapeList):
+        """Intersect two ShapeLists operator &"""
+        return ShapeList(set(self) & set(other))
+
     @overload
     def __getitem__(self, key: int) -> T:
         ...

tests/test_build_common.py

@@ -553,6 +553,14 @@ def test_shapes(self):
             Box(1, 1, 1)
         self.assertIsNone(test._shapes(Compound))
 
+    def test_operators(self):
+        with BuildPart() as test:
+            Box(1, 1, 1)
+        self.assertEqual(
+            (test.faces() | Axis.Z).edges() & (test.faces() | Axis.Y).edges(),
+            (test.edges() | Axis.X)
+        )
+
 
 class TestValidateInputs(unittest.TestCase):
     def test_wrong_builder(self):