private static void MakeDictionaryDeleteTarget(DeleteBindingInfo/*!*/ info) {
info.Body.FinishCondition(
Ast.Call(
typeof(UserTypeOps).GetMethod("RemoveDictionaryValue"),
Ast.Convert(info.Args[0].Expression, typeof(IPythonObject)),
AstUtils.Constant(SymbolTable.StringToId(info.Action.Name))
)
);
}
private static DynamicMetaObject MakeSlotDelete(DeleteBindingInfo/*!*/ info, PythonTypeSlot/*!*/ dts) {
// users can subclass PythonProperty so check the type explicitly
// and only in-line the ones we fully understand.
if (dts.GetType() == typeof(PythonProperty)) {
// properties are mutable so we generate code to get the value rather
// than burning it into the rule.
Expression deleter = Ast.Property(
Ast.Convert(AstUtils.WeakConstant(dts), typeof(PythonProperty)),
"fdel"
);
ParameterExpression tmpDeleter = Ast.Variable(typeof(object), "tmpDel");
info.Body.AddVariable(tmpDeleter);
info.Body.FinishCondition(
Ast.Block(
Ast.Assign(tmpDeleter, deleter),
Ast.Condition(
Ast.NotEqual(
tmpDeleter,
Ast.Constant(null)
),
Ast.Dynamic(
new PythonInvokeBinder(
BinderState.GetBinderState(info.Action),
new CallSignature(1)
),
typeof(void),
Ast.Constant(BinderState.GetBinderState(info.Action).Context),
tmpDeleter,
info.Args[0].Expression
),
Ast.Throw(Ast.Call(typeof(PythonOps).GetMethod("UndeletableProperty")))
)
)
);
return info.Body.GetMetaObject();
}
info.Body.AddCondition(
Ast.Call(
typeof(PythonOps).GetMethod("SlotTryDeleteValue"),
Ast.Constant(BinderState.GetBinderState(info.Action).Context),
AstUtils.Convert(AstUtils.WeakConstant(dts), typeof(PythonTypeSlot)),
AstUtils.Convert(info.Args[0].Expression, typeof(object)),
Ast.Convert(
Ast.Property(
Ast.Convert(
info.Args[0].Expression,
typeof(IPythonObject)),
TypeInfo._IPythonObject.PythonType
),
typeof(PythonType)
)
),
Ast.Constant(null)
);
return null;
}
private static void MakeDeleteAttrTarget(DeleteBindingInfo/*!*/ info, IPythonObject self, PythonTypeSlot dts) {
ParameterExpression tmp = Ast.Variable(typeof(object), "boundVal");
info.Body.AddVariable(tmp);
// call __delattr__
info.Body.AddCondition(
Ast.Call(
TypeInfo._PythonOps.SlotTryGetBoundValue,
Ast.Constant(BinderState.GetBinderState(info.Action).Context),
AstUtils.Convert(AstUtils.WeakConstant(dts), typeof(PythonTypeSlot)),
AstUtils.Convert(info.Args[0].Expression, typeof(object)),
AstUtils.Convert(AstUtils.WeakConstant(self.PythonType), typeof(PythonType)),
tmp
),
Ast.Dynamic(
new PythonInvokeBinder(
BinderState.GetBinderState(info.Action),
new CallSignature(1)
),
typeof(object),
BinderState.GetCodeContext(info.Action),
tmp,
Ast.Constant(info.Action.Name)
)
);
}
private DynamicMetaObject/*!*/ MakeDeleteMemberRule(DeleteBindingInfo/*!*/ info) {
CodeContext context = BinderState.GetBinderState(info.Action).Context;
DynamicMetaObject self = info.Args[0].Restrict(info.Args[0].GetRuntimeType());
IPythonObject sdo = info.Args[0].Value as IPythonObject;
if (info.Action.Name == "__class__") {
return new DynamicMetaObject(
Ast.Throw(
Ast.New(
typeof(ArgumentTypeException).GetConstructor(new Type[] { typeof(string) }),
Ast.Constant("can't delete __class__ attribute")
)
),
self.Restrictions
);
}
// call __delattr__ if it exists
PythonTypeSlot dts;
if (sdo.PythonType.TryResolveSlot(context, Symbols.DelAttr, out dts) && !IsStandardObjectMethod(dts)) {
MakeDeleteAttrTarget(info, sdo, dts);
}
// then see if we have a delete descriptor
sdo.PythonType.TryResolveSlot(context, SymbolTable.StringToId(info.Action.Name), out dts);
ReflectedSlotProperty rsp = dts as ReflectedSlotProperty;
if (rsp != null) {
MakeSlotsDeleteTarget(info, rsp);
}
if (!info.Body.IsFinal && dts != null) {
MakeSlotDelete(info, dts);
}
if (!info.Body.IsFinal && sdo.HasDictionary) {
// finally if we have a dictionary set the value there.
MakeDictionaryDeleteTarget(info);
}
if (!info.Body.IsFinal) {
// otherwise fallback
info.Body.FinishCondition(
FallbackDeleteError(info.Action, info.Args).Expression
);
}
DynamicMetaObject res = info.Body.GetMetaObject(info.Args);
res = new DynamicMetaObject(
res.Expression,
self.Restrictions.Merge(res.Restrictions)
);
return BindingHelpers.AddDynamicTestAndDefer(
info.Action,
res,
info.Args,
info.Validation
);
}
