Compile lambda for null access expressions #3157
Conversation
| [Test] | ||
| public void NullableNullValue() | ||
| { | ||
| int? v = null; | ||
| Expression<Func<int>> expression = () => v.Value; | ||
|
|
||
| Assert.Throws<InvalidCastException>(() => GetValue(expression)); | ||
| Assert.Throws<InvalidCastException>(() => expression.Compile().Invoke()); | ||
| } |
There was a problem hiding this comment.
What about e => v.HasValue || e.SomeProperty = v.Value? I wonder if it is supported or if it would throw.
(There is not much value in supporting this, excepted "feature parity" with linq-to-object: the .Value is not needed in any way in such a query and can just be dropped. But still, it is better to know what how it behaves with NHibernate.)
There was a problem hiding this comment.
It throws on v.Value evaluation:
NHibernate.HibernateException : Evaluation failure on null.Value
----> System.InvalidOperationException : Nullable object must have a value.Maybe we shouldn't try to evaluate it in this context. But it's a different story not related to this PR.
There was a problem hiding this comment.
For sure, it would be beneficial if nullable.Value works (with the SQL parameter becoming false, true, or NULL). The value of supporting this would be that users don't have to remember to adapt their expression specially.
No idea what the effort would be to support it though.
There was a problem hiding this comment.
it would be beneficial if
nullable.Valueworks
Just to clarify things. This PR fixes regression caused by optimizations made in #2948, #2957. nullableNullParam.HasValue or nullableNullParam.GetValueOrDefault() works in 5.3 but throws on master (5.4-dev).
nullable.Value fails the same in 5.3. So it's more like another feature request.
Fixes #3156