[petsc-dev] We need to cleanup viewers

[Barry Smith]

On Mar 27, 2014, at 9:23 AM, Matthew Knepley <knepley at gmail.com> wrote:

> 1) IS was silently ignoring viewers it did not support. I suspect other pieces are
>      doing this as well. Is this what we want?

   Yes, if something has nothing to say it should say nothing, not kill the entire program

> 
>     I cannot think of a reason not to throw an error for unrecognized viewers.

   That was the old model and it was terrible. Thus we changed to silently ignore unrecognized viewers.

> 
> 2) We need to rationalize behavior with conditionally compiled viewers
> 
>     Jed proposes a registration process.

    Finally a real system for double dispatch?

> A simpler, but uglier solution is to
>     protect the dispatch call and speciailzed view function with #ifdef and
>     provide an error at the dispatch point.

  How are we not doing this now?

> 
> We should decide what to do and convert everything in one set.
> 
>     Matt
> 
> -- 
> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
> -- Norbert Wiener