hdl.ast: make Slice const-castable.

Fixes #1006.
2023-12-30 12:10:29 +01:00 · 2023-12-30 12:10:29 +01:00 · 0849e1af0b
commit 0849e1af0b
parent 6780c838b2
4 changed files with 21 additions and 0 deletions
--- a/amaranth/hdl/ast.py
+++ b/amaranth/hdl/ast.py
@ -731,6 +731,9 @@ class Const(Value):
                value |= part_value << width
                width += len(const)
            return Const(value, width)
+        elif type(obj) is Slice:
+            value = Const.cast(obj.value)
+            return Const(value.value >> obj.start, unsigned(obj.stop - obj.start))
        else:
            raise TypeError(f"Value {obj!r} cannot be converted to an Amaranth constant")