[hibernate-dev] AttributeConverter - 6.0

When I first added support for AttributeConverter I incorporated it into BasicType because that was really the only option at the time. As we move into 6.0 though I would like to consider moving this to the new Attribute model. What this means practically speaking is that we'd move AttributeConverter from the definition of BasicType and instead move it to select "domain model reference nodes" identified by a new ConvertibleDomainReference interface. This is already developed initially in the 6.0 wip where basic singular attributes, basic collection indexes and basic collection elements are all considered ConvertibleDomainReferences. This work so far only makes the AttributeConverters available via ConvertibleDomainReference; it does not apply AttributeConverters via ConvertibleDomainReference. That would be the next step if we decide to go this route. Additionally, this would mean that BasicType would no longer contain the AttributeConverter; BasicType then would be the composition of: 1. JavaTypeDescriptor 2. SqlTypeDescriptor 3. MutabilityPlan But even MutabilityPlan... I wonder if that should move to the Attribute model as well? Anyway, please let me know what y'all think of these open questions asap as I'd like to start nailing down the Type SPIs for an Alpha.