[gecode-users] access to Space during branching?

[Luis Quesada]

Christian Schulte wrote:

>No, you always have to update views! If a propagator stores a view it must
>be updated. In the situation you describe it will be that the variable
>implementations to which the views stored in the space have already been
>updated (that is, a copy has been created). However, also the views in the
>propagators must be updated to point to the copied variable implementations.
>
>  
>
OK, I see your point! However, do the propagators (in the particular 
situation I am describing) need to store the views (taking into account 
that the space is an argument (and that I can have access to the views 
through the space))?

Luis

>Christian
>
>-----Original Message-----
>From: Luis Quesada [mailto:luque at info.ucl.ac.be] 
>Sent: Monday, June 05, 2006 12:01 PM
>To: Christian Schulte
>Cc: 'gecode user list'
>Subject: Re: [gecode-users] access to Space during branching?
>
>
>Christian Schulte wrote:
>
>  
>
>>Yes, you got it right. It has been really a mistake to not pass a space 
>>argument to branch: everything is constructed in such a way that one 
>>never has to store a space anywhere: no Gecode data structure stores a 
>>space, all is passed as arguments.
>>
>> 
>>
>>    
>>
>Thanks for your confirmation.
>
>In fact, this made me remember another question: suppose that in my 
>program all the propagators are using the same views of the variables 
>(i.e., there is only one view per variable) and theses views are updated 
>in the constructor for cloning of the space. Is it correct to say that 
>there is no need of updating these views in the constructor for cloning 
>of the propagators (since these views are already updated in the 
>constructor for cloning of the space)?
>
>Luis
>
>  
>


-- 
Luis QUESADA
Catholic University of Louvain 
Department of Computing Science and Engineering 
Place Sainte Barbe, 2 
B-1348 Louvain-la-Neuve, Belgium 
Phone:	(++32) (10) 47 90 13 
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