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

[Slavomir Kaslev]

On 11/28/06, Slavomir Kaslev <slavomir.kaslev at gmail.com> wrote:
> 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?
>
> Cheers.
>
> --
> Slavomir Kaslev
>

Err... Actually I *am* aware of parameterized types. Almost every
function function from the Prelude on lists is parameterized. I was
confused by you post that parameterized types have something to do
with the strictness flag '!'. Sorry for that, going home embarrassed.


-- 
Slavomir Kaslev