[Haskell-cafe] [Haskell] Defining Cg, HLSL style vectors in Haskell

Slavomir Kaslev slavomir.kaslev at gmail.com
Tue Nov 28 13:26:13 EST 2006

On 11/28/06, Bulat Ziganshin <bulat.ziganshin at gmail.com> wrote:
> Hello Slavomir,
> Tuesday, November 28, 2006, 3:46:13 PM, you wrote:
> > Last question: Does haskell have something like C++ templates? For
> > example, some time in the future I may need types like int2, short3,
> > etc., that behave just like float2, float3, but use different types
> > for their components. I really, really wouldn't like to copy-paste the
> > definitions of floatn and manually change their types to intn
> > respectfully.
> yes, it's named parameterized types:
> data Vec2 a = Vec2 !a !a
> instance (Num a) => Num (Vec2 a) where
>    (Vec2 a1 a2) + (Vec2 b1 b2) = Vec2 (a1+b1) (a2+b2)
>    ....
> type Float2 = Vec2 Float

I wasn't aware of parameterized types, they are sweet. Thank you very much.

What about my other questions? Do you have any suggestions? I know
that this is very library specific. All I am asking is for some
Haskell common sense. What would you do, if you were writing this kind
of library?


Slavomir Kaslev

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