[hibernate-dev] Query Parser Redesign

[Steve Ebersole]

Anyone want to propose an alternative approach to what I have working in my
Antlr 4 PoC?

If not, I think we should move that work to a GitHub Hibernate org repo and
start tracking work and Jiras there.  Objections?

Also its no longer *just* HQL, we also plan to support JPA criteria queries
here, interpreting them into semantic query models.  As such I propose the
top-level name of hibernate-query-parser, with 2 sub projects:
hibernate-sqm and hibernate-query-interpreter


On Tue, Aug 25, 2015 at 8:45 AM andrea boriero <dreborier at gmail.com> wrote:

> I see,
>
> Thanks
>
> On 25 August 2015 at 13:17, Steve Ebersole <steve at hibernate.org> wrote:
>
>> from A a where a.b in (from B b ..) and a.c in (from C c ...) ...
>>
>> But regardless, the children are not important for a stack, just the
>> parent.  As I said when we discussed on ORC, the children are just
>> maintained because I used them for tests.
>>
>> On Tue, Aug 25, 2015 at 6:53 AM andrea boriero <dreborier at gmail.com>
>> wrote:
>>
>>> Hi Stevej
>>>
>>> I'm playing with you idea to remove the parent/child from the FromClause
>>> and introduce such a structure in the FromClauseProcessor.
>>>
>>> just a question, in the current implementation a fromClause can have
>>> more than one child fromClause , but I cannot figure out when this happen :(
>>>
>>> Thanks a lot
>>>
>>> On 25 August 2015 at 04:12, Steve Ebersole <steve at hibernate.org> wrote:
>>>
>>>> Andrea, this is in relation to something you asked me on IRC today.
>>>> Specifically in regards to FromClause and the fact that it maintains
>>>> pointers to parent/children.  As I said on IRC there is no intrinsic
>>>> need
>>>> (I do not foresee) for keeping this structure; I really only did that
>>>> because FromCauseProcessor needed a stack of FromClauses and the
>>>> FromClause
>>>> itself made a simple place to do that.
>>>>
>>>> However, in later work I ran into minor problems because of that
>>>> decision.
>>>> I need to make a copy of an entire SelectStatement tree.  But because
>>>> the
>>>> FromClause is held twice (for non-root FromClauses) in the tree, it
>>>> makes
>>>> it more complicated to do a "simple copy" than it need be.  Basically I
>>>> need to maintain a "Map<FromClause,FromClause> copy Map" :(
>>>>
>>>> Long story short, I think I might revisit that decision and instead
>>>> write a
>>>> dedicated stack in FromClauseProcessor for this.  In the morning... its
>>>> too
>>>> late to start something that ambitious tonight.  I'll start that in the
>>>> morning, unless someone wants to pick that up in the next few hours
>>>> before
>>>> I get back on line.
>>>>
>>> _______________________________________________
>>>> hibernate-dev mailing list
>>>> hibernate-dev at lists.jboss.org
>>>> https://lists.jboss.org/mailman/listinfo/hibernate-dev
>>>>
>>>
>>>
>