[gme-users] Ordering of sets in Bon
Attila Vizhanyo
viza at isis.vanderbilt.edu
Fri Apr 30 12:22:42 CDT 2004
Jacques,
Implicit deduction of the template parameter T, where T is presented only by a template (member) function as its return type, is indeed not supported by VC6. The only workaround is to introduce a type T' as a function argument, from which T can be implicitly deduced. (T can be equal to T').
In this context, both the solutions (passing either the set or the comparison functor) can work with VC6, but the extra argument is required anyways.
Too bad for VC6, and another reason to go to VC7.1, which is said to be
ISO C++ 98% compliant according to industry-standard test suites.
Thanks,
Attila
-----Original Message-----
From: Jacques Kerner [mailto:jacques.kerner at oktal.fr]
Sent: Friday, April 30, 2004 10:42
To: gme-users
Subject: Re: [gme-users] Ordering of sets in Bon
Hi Zoltan,
You tried the code on Visual 6 and it did not compile ? Too bad...
Otherwise, my other guess would rather be to have something like (almost
the same as you suggested) :
std::set<B, BComparison> bSet = b->getB( BComparison() )
I think it would be more logical to pass the comparison class as an
argument rather that the set. Would that work with visual 6 ? This would
give you this declaration code :
template <class T>
std::set<B, T> AImpl::getB(const T & aComparison)
{
std::set<B, T> res;
std::set<BON::FCO> roles = getChildFCOsAs("B");
for( std::set<BON::FCO>::iterator i = roles.begin(); i !=
roles.end(); ++i)
{
TypeReference elem(*i);
ASSERT(elem);
res.insert(elem);
}
return res;
}
I tested it on Visual 7.1 and it works fine, but of course you need to test it on Visual 6 (I don't have it on my machine).
Also, I will try to find if there are no workaround for template specialization on Visual 6, and tell you if I find such things...
Jacques Kerner.
Zoltan Molnar a écrit :
>Hi,
>
>Unfortunately VC6.0 doesn't support the specialization "getB<Bcomparison>"
>in
>std::set<B, BComparison> bSet = b->getB<BComparison>();
>
>But a version like this is accepted by vc6, (it doesn't require the
>specialization)
>std::set<B, BComparison> bSet = b->getB( bSet);
>
>Would it be OK?
>
>Zoli
>
>
>
>>-----Original Message-----
>>From: gme-users-bounces at list.isis.vanderbilt.edu
>>[mailto:gme-users-bounces at list.isis.vanderbilt.edu] On Behalf
>>Of Jacques Kerner
>>Sent: Tuesday, April 20, 2004 8:26 AM
>>To: A list for GME users to share thoughts and discuss bugs and fixes.
>>Subject: Re: [gme-users] Ordering of sets in Bon
>>
>>
>>Hi, it's me again, on ordering (sorry).
>>
>>I would still like to suggest an additional generated
>>function to allow
>>the user to specify how a returned set should be ordered.
>>Note that my
>>suggestion does not break the current API.
>>
>>For instance, let's suppose we have Model "A" that can
>>aggregate Atoms
>>"B". What the BONExtender generates is :
>>
>>class AImpl :
>> virtual public BON::ModelImpl
>>{
>>public:
>> std::set<B> getB();
>>};
>>
>>and
>>
>>std::set<B> AImpl::getB()
>>{
>> std::set<B> res;
>> std::set<BON::FCO> roles = getChildFCOsAs("B");
>> for( std::set<BON::FCO>::iterator i = roles.begin(); i !=
>>roles.end(); ++i)
>> {
>> TypeReference elem(*i);
>> ASSERT(elem);
>> res.insert(elem);
>> }
>> return res;
>>}
>>
>>ordering is done in the insert function, and uses the operator< that
>>relies on the reference counter to compare two fcos. I suggest the
>>addition of the following template function to the AImpl
>>class declaration:
>>
>>template <class T>
>>std::set<B, T> AImpl::getB()
>>{
>> std::set<B, T> res;
>> std::set<BON::FCO> roles = getChildFCOsAs("B");
>> for( std::set<BON::FCO>::iterator i = roles.begin(); i !=
>>roles.end(); ++i)
>> {
>> TypeReference elem(*i);
>> ASSERT(elem);
>> res.insert(elem);
>> }
>> return res;
>>}
>>
>>Adding this function allows the user to use his own comparison Trait :
>>
>>std::set<B, BComparison> bSet = b->getB<BComparison>();
>>
>>with, for instance, a Comparison class based on the x coordinate in
>>"MyAspect" aspect.
>>
>> class BComparison
>> {
>> public:
>> //! This method orders two Bs with respect to their x
>>coordinate
>>in the diagram
>> /** (thanks to Peter Volgyesi for the trick... :)
>> */
>> bool operator()(
>> const B& _Left,
>> const B& _Right
>> ) const
>> {
>> return
>>(_Left->getRegistry()->getLocation("MyAspect").first
>>< _Right->getRegistry()->getLocation("MyAspect").first);
>> }
>> };
>>
>>or whatever Trait the user defines for his own needs.
>>
>>Again, please note that my suggestion does not break the current API,
>>since the user can still call the regular untemplated getB() method.
>>Furthermore, this does not imply any additional performance
>>cost other
>>than implied by the user comparison function. Using this
>>avoids the need
>>to reorder the sets after they have been recovered. If the
>>user wants to
>>get the set as fast as possible, she uses the untemplated
>>getB() method,
>>but if she wants to order it in her own way, this is still
>>faster that
>>getting the set and THEN reordering it.
>>
>>I have succesfully tested this method with GME 4.3.17, with
>>Visual 7.1.
>>Hoping there are no issues with this that I am anaware of ...
>>
>>Best Regards,
>>
>>Jacques Kerner.
>>
>>Peter Volgyesi a écrit :
>>
>>
>>
>>>Hi,
>>>
>>>Collections coming from the model database are never
>>>
>>>
>>ordered. (This is
>>
>>
>>>a property of our modeling engine and not BON specific, and it is
>>>because of internal caching mechanisms.) One can argue, why don't we
>>>order these lists, however it seems a better (general)
>>>
>>>
>>approach to me
>>
>>
>>>to provide data as fast as possible that can be sorted by the upper
>>>layers on demand.
>>>
>>>Anyway, the MONTraverser interpreter (Paradigms/MetaGME folder) does
>>>implement some kind of sorting (MONDialog.cpp). Feel free to
>>>
>>>
>>use that
>>
>>
>>>code.
>>>
>>>For retrieving graphical position of an object in a given
>>>
>>>
>>aspect, use
>>
>>
>>>this:
>>>fco->getRegistry()->getLocation("AspectName");
>>>
>>>fco must be a BON FCO object (eg.: BON::Atom)
>>>
>>>Regards,
>>>
>>>--
>>>peter
>>>
>>>
>>>
>>>
>>>
>>>
>>>>-----Original Message-----
>>>>From: gme-users-bounces at list.isis.vanderbilt.edu
>>>>[mailto:gme-users-bounces at list.isis.vanderbilt.edu] On Behalf
>>>>Of Jacques Kerner
>>>>Sent: Tuesday, April 06, 2004 9:45 AM
>>>>To: A list for GME users to share thoughts and discuss bugs
>>>>
>>>>
>>and fixes.
>>
>>
>>>>Subject: [gme-users] Ordering of sets in Bon
>>>>
>>>>Hi,
>>>>
>>>>I would like to know how the std::set<...> returned by
>>>>BONExtender generated functions are ordered. For instance, I
>>>>have a model named "Container" that aggregates "Contained"
>>>>Atoms "contained1", "contained2"
>>>>and "contained3" and I was uable to figure out how the
>>>>ordering was made. Sometimes the order is by creation of the
>>>>contained elements, sometimes not, ...
>>>>
>>>>Is there a way to impose the ordering on the returned sets ?
>>>>Do I have to define a specific operator < for this ? Could
>>>>BonExtender generate one from a rule in the meta model ?
>>>>
>>>>I also wondered if one can retrieve the position of elements
>>>>in diagrams in BON .
>>>>
>>>>Thank you in advance.
>>>>
>>>>Jacques Kerner. _______________________________________________
>>>>gme-users mailing list
>>>>gme-users at list.isis.vanderbilt.edu
>>>>http://list.isis.vanderbilt.edu/mailman/listinfo/gme-users
>>>>
>>>>
>>>>
>>>>
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>>>
>>>
>>>
>>>
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