[hibernate-dev] ORM, OGM and timing

[Emmanuel Bernard]

My fear was simply that TypeDescriptor was a class hosted on Hibernate
ORM's codebase. But in retrospect I made that up on my own.

If we have access to the type information via a given class - say
TypeDescriptor -  and that TypeDescriptor is hosted on the query parser
project then, we don't have any immediate problem and we can continue to
release OGM when we want while the beefing-up phase of the parser is
done to accommodate ORM's needs.

Of course I understand that the project specific walker (not sure that's
the correct term), will be able to downcast TypeDescriptor - via the is() / as()
pattern - to access the native type (ORM's Type / GridType) system if necessary.

Emmanuel

On Wed 2012-12-05 12:36, Steve Ebersole wrote:
> By "type system" do you mean the TypeDescriptor pull request?  If
> not, you'll have to clarify.
> 
> If so...
> 
> The idea is simple.  There are a number of things that the parser
> needs to know in order to figure out the semantics of the query;
> this question of "types" is just one thing.  However, ORM and OGM
> have different concrete contracts (Type versus GridType) there.
> TypeDescriptor is simply a "bridge" contract that the parser can use
> in making these semantic decisions.  Let's take a few simple
> examples:
> 
> 1) ... where p.age + p.birthdate > p.name
> 
> Is that a valid restriction?
> 
> 2) ... from Person p join p.aliases a
> 
> Is that a valid join (not as straight forward as I think you think)?
> 
> etc
> 
> Answering all those questions depends on access to "type information".
> 
> I cannot give you exact details on exactly how the parser determines
> "type information" for each expression yet because we still have
> other unanswered questions that affect the answer to that (most
> notably the question of heterogeneous trees versus homogeneous
> trees).
> 
> 
> On Wed 05 Dec 2012 10:02:00 AM CST, Sanne Grinovero wrote:
> >That's what I'm hoping too, but since I've not fully grasped the
> >proposed solution for the type system I'm not sure: I need to read the
> >new ORM code.
> >
> >If we really can just plug a different QueryTranslatorFactory in ORM,
> >how does this affect our release options on OGM?
> >
> >
> >On 5 December 2012 15:44, Steve Ebersole <steve at hibernate.org> wrote:
> >>I am not completely understanding the question.  You don't *need* Hibernate
> >>5, you could just plug in a custom QueryTranslatorFactory as we discussed on
> >>irc.  The discussion here was changing the standard QueryTranslatorFactory
> >>to use this new Antlr parser.
> >>
> >>On Dec 5, 2012 8:46 AM, "Sanne Grinovero" <sanne at hibernate.org> wrote:
> >>>
> >>>Do we need Hibernate 5 to resolve those type system issues?
> >>>
> >>>If so, is there an alternative solution which wouldn't necessarily
> >>>couple the OGM lifecycle with ORM ? (just for the time being)
> >>>
> >>>
> >>>On 4 December 2012 18:19, Emmanuel Bernard <emmanuel at hibernate.org> wrote:
> >>>>Moving to dev mailing list.
> >>>>
> >>>>On Tue 2012-12-04 12:09, Steve Ebersole wrote:
> >>>>>Can we have such discussions on the dev list?
> >>>>>
> >>>>>Anyway, that's why I said about developing the parser separately but in
> >>>>>tandem and synching later.  That gives us that flexibility.
> >>>>>
> >>>>>Because it's not been decided that the parser change will even go into
> >>>>>5.0...
> >>>>>On Dec 4, 2012 11:35 AM, "Emmanuel Bernard" <emmanuel at hibernate.org>
> >>>>>wrote:
> >>>>>
> >>>>>>Hey guys,
> >>>>>>
> >>>>>>Steve and I started a discussion on how to reuse Sanne's work around
> >>>>>>the
> >>>>>>new JP-QL parser. The crux of the problem is to be able to reuse the
> >>>>>>type
> >>>>>>of a given node in the parser even if Hibernate ORM and Hibernate OGM
> >>>>>>use a
> >>>>>>different type system. This looks doable but then the problem of
> >>>>>>timing
> >>>>>>arises.
> >>>>>>
> >>>>>>With Davide coming onboard, and even more after BV is behind us, I
> >>>>>>expect
> >>>>>>OGM to speed up significantly which means we will need to do fast
> >>>>>>releases.
> >>>>>>So the question is when are we targeting Hibernate ORM 5 final and
> >>>>>>does
> >>>>>>that fit Hibernate OGM's time goals.
> >>>>>>
> >>>>>>We have been promising query for ever now and I would hate to have to
> >>>>>>delay it more than necessary.
> >>>>>>
> >>>>>>Thoughts?
> >>>>>>
> >>>>>>Emmanuel
> >>>>>>
> >>>>_______________________________________________
> >>>>hibernate-dev mailing list
> >>>>hibernate-dev at lists.jboss.org
> >>>>https://lists.jboss.org/mailman/listinfo/hibernate-dev