lib.data: make views of ArrayLayout iterable.

amaranth/lib/data.py

@@ -856,6 +856,12 @@ def __len__(self):
                 f"`len()` can only be used on views of array layout, not {self.__layout!r}")
         return self.__layout.length
 
+    def __iter__(self):
+        if not isinstance(self.__layout, ArrayLayout):
+            raise TypeError(
+                f"Only views of array layout can be iterated, not {self.__layout!r}")
+        return (self[i] for i in range(self.__layout.length))
+
     def __eq__(self, other):
         if isinstance(other, View) and self.__layout == other.__layout:
             return self.__target == other.__target

tests/test_lib_data.py

@@ -771,6 +771,14 @@ def test_len(self):
         s2 = Signal(data.ArrayLayout(2, 3))
         self.assertEqual(len(s2), 3)
 
+    def test_iter(self):
+        s1 = Signal(data.StructLayout({"a": unsigned(2)}))
+        with self.assertRaisesRegex(TypeError,
+                r"^Only views of array layout can be iterated, not StructLayout.*$"):
+            iter(s1)
+        s2 = Signal(data.ArrayLayout(2, 3))
+        self.assertRepr(tuple(s2), "((slice (sig s2) 0:2), (slice (sig s2) 2:4), (slice (sig s2) 4:6))")
+
     def test_operator(self):
         s1 = Signal(data.StructLayout({"a": unsigned(2)}))
         s2 = Signal(unsigned(2))