hdl: remove ValueCastable.lowermethod.

Author: wanda-phi

amaranth/hdl/_ast.py

@@ -1472,20 +1472,6 @@ def shape(self, *args, **kwargs):
         """
         return super().shape(*args, **kwargs) # :nocov:
 
-    # TODO(amaranth-0.6): remove
-    @staticmethod
-    @deprecated("`ValueCastable.lowermethod` is no longer required and will be removed in Amaranth 0.6")
-    def lowermethod(func):
-        @functools.wraps(func)
-        def wrapper_memoized(self, *args, **kwargs):
-            # Use `in self.__dict__` instead of `hasattr` to avoid interfering with custom
-            # `__getattr__` implementations.
-            if not "_ValueCastable__lowered_to" in self.__dict__:
-                self.__lowered_to = func(self, *args, **kwargs)
-            return self.__lowered_to
-        wrapper_memoized.__memoized = True
-        return wrapper_memoized
-
 
 class _ValueLikeMeta(type):
     def __subclasscheck__(cls, subclass):

tests/test_hdl_ast.py

@@ -1483,30 +1483,15 @@ def as_value(self):
         return self.dest
 
 
-class MockValueCastableChanges(ValueCastable):
-    def __init__(self, width=0):
-        self.width = width
-
-    def shape(self):
-        return unsigned(self.width)
-
-    with _ignore_deprecated():
-        @ValueCastable.lowermethod
-        def as_value(self):
-            return Signal(self.width)
-
-
 class MockValueCastableCustomGetattr(ValueCastable):
     def __init__(self):
         pass
 
     def shape(self):
         assert False
 
-    with _ignore_deprecated():
-        @ValueCastable.lowermethod
-        def as_value(self):
-            return Const(0)
+    def as_value(self):
+        return Const(0)
 
     def __getattr__(self, attr):
         assert False
@@ -1531,16 +1516,6 @@ def __init__(self):
                 def as_value(self):
                     return Signal()
 
-    def test_memoized(self):
-        vc = MockValueCastableChanges(1)
-        sig1 = vc.as_value()
-        vc.width = 2
-        sig2 = vc.as_value()
-        self.assertIs(sig1, sig2)
-        vc.width = 3
-        sig3 = Value.cast(vc)
-        self.assertIs(sig1, sig3)
-
     def test_custom_getattr(self):
         vc = MockValueCastableCustomGetattr()
         vc.as_value() # shouldn't call __getattr__