[Dune] Returning Geometries As Objects

[Martin Nolte]

Hi Christian,

first of all, your objection is noted and I will not merge the branch before 
the issue is decided upon.

However, I think this issue does not just concern the grid implementors. It 
might also have a performance impact on existing codes. Currently, it is 
usually ok to fetch the geometry multiple times, because the entity can ensure 
that it is built up only once.

Therefore, I think that a formal vote on the lifetime issue is in order 
(that's why I wanted to postpone it until the next meeting).

Since you are pressing the issue, I think we should split up the issues a 
little. For example:

(a) Should we postpone the merge?
(b) Should we decide on the lifetime issue now or later?
(c) May the lifetime be limited (by entity / intersection) or not? (Maybe 
capability?)
(d) Should the lifetime issue be a showstopper for the next release (i.e., no 
transition phase)?
(e) Should we make another release before we merge?

I think postponing the merge will increase maintenance costs and slow down 
development, so I'd like the merge to happen soon. Moreover, I also think 
there will be a lively discussion of (c), so I don't know whether deciding now 
makes sense.

What are the opionions of the other developers?

Best,

Martin



On 02/07/2012 10:50 AM, Christian Engwer wrote:
> Hi Martin,
>
> just as a follow up of my last mail.
>
>> Currently, my impression is as follows: Carsten and Oli would like
>> to enhance the lifetime of the geometry objects, Robert agrees to
>> merge, and some users are afraid of breaking their code. Of course,
>> the positive decision on the last developer meeting is positive
>> towards this change.
>>
>> *NOTICE*: This is the final announcement. Unless a developer
>> objects, the branch will be merged 2 PM today!
>
> I'm against a merge, unless we agree to disable the reference feature
> before the next release. Yes, this will require updates in all grid
> implementations, but I think it is necessary to make this change show
> its full potential and to actually value all the work and time you
> spent here.
>
> If we can agree on this, I have no furthe objections regarding a
> merge. I think it is well enough tested to actually do a merge. My
> main concern is about adding undesired features which we (might) have
> to deal with for an unforseable time.
>
> And "we agree" does not necessarily require a formal vote. I think it
> just means that those people involved in (core) grid implementations
> have to agree. I, for my part, am willing to do add the necessary
> changes. Now we only need an opinion from Robert and Oliver [assuming
> that you actually want to use you new feature ;-)].
>
> Cheers
> Christian
>

-- 
Dr. Martin Nolte <nolte at mathematik.uni-freiburg.de>

Universität Freiburg                                   phone: +49-761-203-5630
Abteilung für angewandte Mathematik                    fax:   +49-761-203-5632
Hermann-Herder-Straße 10
79104 Freiburg, Germany