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

28 Nov 2006


      On 11/28/06, Slavomir Kaslev  wrote:
...
On 11/28/06, Bulat Ziganshin  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