Fwd (kielmann at cs.vu.nl): Re: [saga-rg] SAGA, object states, and concurrency

[Andre Merzky]

Quoting [Thilo Kielmann] (Aug 03 2006):
> 
> it is not clear (to me ;-) why
> prev. error condition and callbacks MUST NOT get copied
> can anybody give a motivation for this, please? 
> (and include it in the document)

just about that for now:

 - about the error condition: I think it makes sense to
   start a new object instance with a clean error record.
   I am not sure though - either way is fine with me.

 - about the callbacks: callbacks have a simple way to avoid
   getting called twice (they get removed on returning
   false).  By copying the cb's to the new instance, that
   mechanism is effectively disabled (the cb can be called
   on both instances, hence twice).  Also, a cb is a
   application level object, so the SAGA implementor has no
   control whatsoever on how large that object is, and copying
   can be very expensive.  

Cheers, Andre.

-- 
"So much time, so little to do..."  -- Garfield