Re: [Haskell-cafe] Interesting feature
Thanks a lot Neil, I will definitely read it. I searched google and found the same article here for free http://www.cs.chalmers.se/~emax/wired/documents/LP_HFL07.pdf I didn't know that Haskell commuity is so alive. Much more answers in much less time than when I wrote something to jav:) Fero Neil Mitchell wrote: > > Hi > >> Hi I have read in one tutorial (I can't find it again, but it was >> probably >> either one on ibm, gentle introduction or yaht), that it is possible to >> define relationships between free variables and the same program can be >> used >> to calculate either first variable when second is set or second when >> first >> is set. > > Here is how to do it in Haskell: > > http://portal.acm.org/citation.cfm?id=1291201.1291207 > > Thanks > > Neil > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > > -- View this message in context: http://www.nabble.com/Interesting-feature-tp18311432p18314566.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Interesting feature
Hi > Hi I have read in one tutorial (I can't find it again, but it was probably > either one on ibm, gentle introduction or yaht), that it is possible to > define relationships between free variables and the same program can be used > to calculate either first variable when second is set or second when first > is set. Here is how to do it in Haskell: http://portal.acm.org/citation.cfm?id=1291201.1291207 Thanks Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Interesting feature
fero wrote: Hi I have read in one tutorial (I can't find it again, but it was probably either one on ibm, gentle introduction or yaht), that it is possible to define relationships between free variables and the same program can be used to calculate either first variable when second is set or second when first is set. I have understood this as if I set first free variable, run program and write name of second variable and I get result, and vice versa. I don't know if I understood it well. It looks really interesting but I can't figure out how to do it. Is this really possible? (I doubt.) If yes show example please. See also metafont, which defines equational relationships between variables and solves. Jules ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Interesting feature
Robin Green wrote: On Mon, 07 Jul 2008 12:30:34 +0200 (CEST) Henning Thielemann <[EMAIL PROTECTED]> wrote: Actually the type system of Haskell is also logic programming. I have implemented a simple kind of logic programming using lazy peano numbers: http://darcs.haskell.org/unique-logic/ There is also Curry which is basically Haskell extended with features from logic programming. There you get to use ordinary values instead of having to use types. However, it seems that Curry's solution finding mechanism is built-in to the language and cannot be modified (e.g. for performance reasons) without modifying the language implementation. (I Actually, I think it can: http://dblp.uni-trier.de/rec/bibtex/conf/iclp/HanusS98 Also more recently, I heard of a way to abstract a nondeterministic Curry value into its explicit search tree, which one can then traverse to one's own liking. Obviously, people on the Curry list will know more about the details... Ciao, Janis. -- Dr. Janis Voigtlaender http://wwwtcs.inf.tu-dresden.de/~voigt/ mailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Interesting feature
On Mon, 07 Jul 2008 12:30:34 +0200 (CEST) Henning Thielemann <[EMAIL PROTECTED]> wrote: > Actually the type system of Haskell is also logic programming. I > have implemented a simple kind of logic programming using lazy peano > numbers: http://darcs.haskell.org/unique-logic/ There is also Curry which is basically Haskell extended with features from logic programming. There you get to use ordinary values instead of having to use types. However, it seems that Curry's solution finding mechanism is built-in to the language and cannot be modified (e.g. for performance reasons) without modifying the language implementation. (I think the same would be true for logic programming with Haskell types.) -- Robin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Interesting feature
On Mon, 7 Jul 2008, fero wrote: Hi I have read in one tutorial (I can't find it again, but it was probably either one on ibm, gentle introduction or yaht), that it is possible to define relationships between free variables and the same program can be used to calculate either first variable when second is set or second when first is set. I have understood this as if I set first free variable, run program and write name of second variable and I get result, and vice versa. I don't know if I understood it well. It looks really interesting but I can't figure out how to do it. Is this really possible? (I doubt.) If yes show example please. Are you talking about logic programming and PROLOG? $ pl # swi-prolog ?- plus(X,2,3). X = 1 ; No ?- plus(1,X,3). X = 2 ; No ?- plus(1,2,X). X = 3 ; No Actually the type system of Haskell is also logic programming. I have implemented a simple kind of logic programming using lazy peano numbers: http://darcs.haskell.org/unique-logic/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Interesting feature
Hi I have read in one tutorial (I can't find it again, but it was probably either one on ibm, gentle introduction or yaht), that it is possible to define relationships between free variables and the same program can be used to calculate either first variable when second is set or second when first is set. I have understood this as if I set first free variable, run program and write name of second variable and I get result, and vice versa. I don't know if I understood it well. It looks really interesting but I can't figure out how to do it. Is this really possible? (I doubt.) If yes show example please. Thanks Fero -- View this message in context: http://www.nabble.com/Interesting-feature-tp18311432p18311432.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
