From cc9fe8904983ea1226a2615e8f185fad43bfb719 Mon Sep 17 00:00:00 2001
From: Jaro Habiger <jarohabiger@googlemail.com>
Date: Wed, 3 Jan 2024 14:11:33 +0100
Subject: [PATCH] hdl.ast: fix Array not being indexable by ValueCastable

---
 amaranth/hdl/ast.py   |  2 ++
 tests/test_hdl_ast.py | 12 ++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/amaranth/hdl/ast.py b/amaranth/hdl/ast.py
index 70e4763..c7822aa 100644
--- a/amaranth/hdl/ast.py
+++ b/amaranth/hdl/ast.py
@@ -1382,6 +1382,8 @@ class Array(MutableSequence):
         self._mutable  = True
 
     def __getitem__(self, index):
+        if isinstance(index, ValueCastable):
+            index = Value.cast(index)
         if isinstance(index, Value):
             if self._mutable:
                 self._proxy_at = tracer.get_src_loc()
diff --git a/tests/test_hdl_ast.py b/tests/test_hdl_ast.py
index b97b2a1..2d9ef2a 100644
--- a/tests/test_hdl_ast.py
+++ b/tests/test_hdl_ast.py
@@ -1005,6 +1005,18 @@ class ArrayTestCase(FHDLTestCase):
                 r"^Array can no longer be mutated after it was indexed with a value at "):
             a.insert(1, 2)
 
+    def test_index_value_castable(self):
+        class MyValue(ValueCastable):
+            @ValueCastable.lowermethod
+            def as_value(self):
+                return Signal()
+            
+            def shape():
+                return unsigned(1)
+        
+        a = Array([1,2,3])
+        a[MyValue()]
+
     def test_repr(self):
         a = Array([1,2,3])
         self.assertEqual(repr(a), "(array mutable [1, 2, 3])")