On 9 Apr 2008, at 16:26, Henning Thielemann wrote:
1. elementwise multiplication 2. convolution
and you have some function which invokes the ring multiplication
f :: Ring a => a -> a
and a concrete sequence
x :: Sequence Integer
what multiplication (elementwise or convolution) shall be used for computing (f x) ?
In math, if there is a theorem about a ring, and one wants to apply it to an object which more than one ring structure, one needs to indicate which ring to use. So if I translate, then one might get something like class Ring (a; o, e, add, mult) ... ... class Ring(a; o, e, add, (*)) => Sequence.mult a Ring(a; o, e, add, (**) => Sequence.conv a where ... Then Sequence.mult and Sequence.conv will be treated as different types whenever there is a clash using Sequence only. - I am not sure how this fits into Haskell syntax though. This might be useful, if it can be worked out. Hans