[saga-rg] deep copy / shallow copy

[Andre Merzky]

Hi Thilo, 


Quoting [Thilo Kielmann] (Sep 11 2005):
> 
> Hi Andre and all,
> 
> regarding copy semanctics of SAGA calls: (shallow vs. deep
> vs. references)
> 
> > As the SAGA implementation should obviously show the

Ah, typo: implemention_S_

> > same behaviour (either one for now), the spec needs to
> > define that obviously.
> 
> Not quite. These issues are certainly beyond SAGA
> functionality.  Rather, this should be addressed by the
> respective language bindings.  For each language, the SAGA
> spec might "prescribe" to stick with the conventions of
> each language.  IMHO, this would contribute to the
> "simple" attribute of SAGA: it would be simple as would do
> in any language what programmers are used to.
> 
> In your case, the C++ binding could prescribe shallow
> copies (and maybe explicit "clone"), as this is what C++
> does usually...

I think I disagree here.  For one thing, as far as I
understood there is no convention which holds for C++ in
general, or for C in general etc. 

Second, that would lead to semantical differences in the
different languages.  I guess we don't want that.  E.g., the
following code would then possibly behave differently in
C++/Java:

+-----------------------------------------------------------------+
  saga::job_description jd_1 = my_job.get_job_description ();
  saga::job_description jd_2 = jd_1;

  jd_2.set_attribute ("SAGA_Host", "localhost");
+-----------------------------------------------------------------+

The state of jd_2 would differ in C++ and Java then, and I'd
think we would like to avoid that, don't we?  If we allow
that, you basically have to re-learn (small parts of) the
semantics for SAGA for each language...

Cheers, Andre.


> My two cents,
> 
> Thilo

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