Re: [Haskell-cafe] Assimp FFI Library

John and Stephen, Thanks for the suggestions! I'm going to evaluate them more fully to see if they're what I'm looking for. Even though I tried looking through the vector packages I managed to miss those (there are a lot of packages with "vec" in their name). Jason, Wow, great suggestions! To address a few questions you raised, instead of {-# UNPACK #-} pragmas, I used {-# OPTIONS_GHC -funbox-strict-fields #-}. I believe this is equivalent to using the pragma on all of the strict fields. It seems my operators aren't quite as intuitive as I hoped they would be, The three examples I provided would be: (|*|) :: Vec n a t1 -> Vec n a t2 -> Vec n a t3, (|*||) :: Vec n a t -> Mat n a -> Vec n a t, (||*) :: Mat n a -> a -> Mat n a. These represent componentwise vector multiplication, plain vector-matrix multiplication, and matrix-scalar multiplication. The idea is that "||" represents a matrix, "|" represents a vector, and "" represents a scalar. Also, I currently have a macro for the three sizes of vector and the three sizes of matrix. I'm not going to mess around with it for now. -Joel On Tue, Apr 12, 2011 at 9:14 AM, John Lato wrote:

From: Joel Burget

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Subject: [Haskell-cafe] Assimp FFI Library To: haskell-cafe@haskell.org Message-ID: Content-Type: text/plain; charset="iso-8859-1"

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5. I've reduced a lot of boilerplate in Vec.hs by using the CPP preprocessor extension. I could reduce the boilerplate by another factor of 3 if I could recursively call templates but that's not allowed. I would like to have one template to generate both of these lines:

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data Vec N2 Double t = Vec2D !Double !Double deriving (Show, Eq) data Vec N3 Double t = Vec3D !Double !Double !Double deriving (Show, Eq)

Notice there is an extra !Double in the second. Is there an easy way to do this? I don't know much about Template Haskell, would that work? Would it be easy?

Yes, it works, and it's pretty easy. My adaptive-tuple package, http://hackage.haskell.org/package/adaptive-tuple, provides this (as well as strict vectors up to 20 elements). Tuple is a bit of a misnomer. You'll need to download the source to get the Template Haskell splices because they aren't exported (tarball from hackage, or via http://www.tiresiaspress.us/haskell/adaptive-tuple/)

John L.