Hi Christian, > Please do not hesitate to ask more questions of that sort! Do you consider > to only do branching or also propagation? Because there is a very > interesting issue for edge-finding/first-last: both propagation and > branching should share the same data structures to maintain their > information for efficiency. Support for sharing state among several > propagators/branching is on our todo list for a long time but we decided to > only do it when we implement exactly what you are now appareantly trying to > do... >
I am in a similar situation now. Could you please explain why (if this is the case indeed) is it not possible to just share the data in some raw data structure inside the Space? I mean, in the above mentioned case, propagation computes some information that can be re-used in the branching. I was under the impression that the following might work in similar cases: - During propagation, store (overwrite) some "raw" data in the Space instance (I know, this is not exactly a good architecture design...) - As soon as the Space is stable, the system looks for active branchings, asking for alternatives - The branching might access the data now, knowing that it is the result of the last propagation (which led to the fixpoint), and return some alternatives The thing I'm not sure about is whether there must always be a propagation step after recomputation. In case that not, the branching should have the possibility to compute the data from scratch, using only the variables' domains (in this case, copying the space should invalidate the data to make sure it is recomputed). The reason I believe this could work is that the shared information is after all just some kind of cache which reflects the current domains. Thanks for any comments, Filip _______________________________________________ Gecode users mailing list [EMAIL PROTECTED] https://www.gecode.org/mailman/listinfo/gecode-users
