How overload operator in Haskell?

[Wolfgang Jeltsch]

On Wednesday, 2003-07-09, 17:11, CEST, Hal Daume wrote:
> What you want to do is make your Vector an instance of the Num(eric) type
> class.

It would be better to define one's own operators instead of using + and - 
because Vector has no meaningful instance of Num (as Jerzy Karczmarczuk 
already pointed out). But maybe it's overkill to define a new class if you 
don't want the same operators for other types.

>  For instance:
>
> instance Num Vector where
>   (+) v1 v2 = zipWith (+) v1 v2
>   (-) v1 v2 = zipWith (-) v1 v2

You can also use the nice infix syntax in definitions (as you already did with 
your `vadd` and `vsub`):
    v1 + v2 = zipWith (+) v1 v2
    v1 - v2 = zipWith (-) v1 v2

> [...]

Wolfgang