[Haskell-cafe] vector-space and standard API for vectors
daniel.is.fischer at web.de
Sat Oct 23 17:01:20 EDT 2010
On Saturday 23 October 2010 22:53:32, Alexey Khudyakov wrote:
> > type family Scalar :: * -> *
> > class Additive v => LeftModule v where
> > (*^) :: Scalar v -> v -> v
> > class Additive v => RightModule v where
> > (^*) :: v -> Scalar v -> v
> Could you give some example of data type for which (*^) ≠ flip (^*)?
> I couldn't imagine one.
Take any noncommutative ring R (quaternions for example) and consider the
space R^n as a) a left R-module and b) a right R-module.
More information about the Haskell-Cafe