In Oz, the "choice" statement needs to be executed within a search. Otherwise it just blocks because nobody has decided which alternative should be tried. It is just like FD.distribute. Only useful within search. I don't think you can have anything like choice points outside of search (or outside of the use of spaces directly). (Somebody please correct me if I'm wrong.)
Cheers, Wolfgang On Tue, Feb 9, 2010 at 3:35 PM, mark richardson <[email protected]>wrote: > Hi, > > The question arises from some work a colleague of mine is doing in formal > methods. They use FORTH as a prototype language so a 'direct recursive > algorithm' would be best but they are also testing the use of choice points, > so choice (or something similar) is necessary. > What would be ideal would be a single tail-recursive function with > integrated choice. > > Regards > > Mark > > Wolfgang Meyer wrote: > > P.S.: If you really need performance, you should probably use a direct > recursive algorithm for the n-ary Cartesian product, without using > search/logic programming. > > Cheers, > Wolfgang > > > On Tue, Feb 9, 2010 at 2:05 PM, mark richardson > <[email protected]>wrote: > >> Hi, >> >> I have a short script to calculate all possible combinations of a list >> such as [1#2 3 4#5] , the tuples representing a choice between two values. >> Solutions to this would be [1 3 4] [1 3 5] [2 3 4] [2 3 5] for example. >> The problem translates quite nicely into a constraint based search using >> FD but it set me wondering if their was a more efficient approach using >> choice or dis recursively (ie. without using loops) >> I've had no success as yet trying to find such a solution and wondered if >> anyone had any opinions on this? >> >> Regards >> >> Mark >> >> -- >> Mark Richardson MBCS >> Research Assistant >> University of Teesside, UK >> Email: [email protected] >> [email protected] >> Skype: mark.richardson. >> >> >> _________________________________________________________________________________ >> mozart-users mailing list >> [email protected] >> http://www.mozart-oz.org/mailman/listinfo/mozart-users >> > > ------------------------------ > > _________________________________________________________________________________ > mozart-users mailing list > [email protected]http://www.mozart-oz.org/mailman/listinfo/mozart-users > > > > -- > Mark Richardson MBCS > Research Assistant > University of Teesside, UK > Email: [email protected] > [email protected] > Skype: mark.richardson. > > > > _________________________________________________________________________________ > mozart-users mailing list > [email protected] > http://www.mozart-oz.org/mailman/listinfo/mozart-users >
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