[Dune] Capability hasLevelIterator?

[Christian Engwer]

Hi,

On Mon, Nov 06, 2006 at 02:24:14PM +0100, Andreas Dedner wrote:
> We should be very carfull with introducing Capabilities - I'm
> not saying we should not do it, but just to be carfull.
> For example it was also difficult to include level iterators into
> Alberta and with a Capability we would probaply have never done
> it. For that I would suggest to add more Default Implementations -
> A Level(0) Iterator and a hierarchicIterator is all it takes...

I agree with Andreas in the point that default implementation should
be taken into account and we should be careful with the introduction
of additional capabilities. Nevertheless I think that the
leveliterator would be a good candidate -- perhaps wit a little
different naming. As you already mentioned Alberta... Alberta supports
Leveliterators, but fails on Levelintersectioniterators. But
Leveliterators without Levelintersectioniterators in generell are
rather useless, please correct me, if I overlooked something. Therefor
I think we should have some way so tell the user that The
level-feature-set is not complete. We can then describe further that
Alberta supports Leveliterators, but not Levelintersectioniterators.

How much more work would it be to implement a
DefaultLevelintersectioniterator, or to add the
Levelintersectioniterator to Alberta? If your answer is "much", I
would suggest to allow grids to implement leveliterators only
partially and report this fact to the user via a capability. If we
have a working default implementation... great :-) then we don't need
the capability.

My .02$...
  Christian