What you want to do is make your Vector an instance of the Num(eric) type class. For instance:
instance Num Vector where (+) v1 v2 = zipWith (+) v1 v2 (-) v1 v2 = zipWith (-) v1 v2 negate v1 = map negate v1 abs v1 = map abs v1 (*) v1 v2 = ... fromInteger i = ... signum v1 = ... I've left the last three blank because it's unclear what should go there. Since (*) has type Vector->Vector->Vector (in this instance), you can't use dot product or something like that. signum :: Vector->Vector could be written and just return [-1], [0] or [1], I suppose. fromInteger :: Integer->Vector is a little harder. Perhaps just 'fromInteger i = [fromInteger i]' would be acceptable. Or you could leave these undefined. -- Hal Daume III | [EMAIL PROTECTED] "Arrest this man, he talks in maths." | www.isi.edu/~hdaume > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Liu Junfeng > Sent: Wednesday, July 09, 2003 7:25 AM > To: [EMAIL PROTECTED] > Subject: How overload operator in Haskell? > > > I've learned haskell months, but I still can't understand the > type system very well. > I can only write: > ----------------------------------- > type Vector = [Double] > vadd,vsub :: Vector->Vector->Vector > v1 `vadd` v2 = zipWith (+) v1 v2 > v1 `vsub` v2 = zipWith (-) v1 v2 > svmul :: Double->Vector->Vector > s `svmul` v = map (s*) v > ------------------------------------ > Tough it works, it is not convenient to use. How to create a > Vector type and overload > mathematical operators? > Thanks for your help. > > Liu Junfeng > [EMAIL PROTECTED] > > > > _______________________________________________ > Haskell mailing list > [EMAIL PROTECTED] > http://www.haskell.org/mailman/listinfo/haskell > _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
