[Haskell-beginners] How to initialize a C struct with FFI

6 Feb 2010

      Hi,

I try to initialize a C struct using the FFI API and ghc stays blocked when
I execute my code (and I got sometimes the error "out of memory").
I do not understand, I do not find any mistake in my code:

{-# OPTIONS -XTypeSynonymInstances #-}

import Foreign.C.Types
import Foreign.Marshal.Alloc
import Foreign.Ptr
import Foreign.Storable

type CStruct = (CULong, CULong)

instance Storable CStruct where
  sizeOf _ = 2*sizeOf (undefined::CULong)
  alignment _ = alignment (undefined::CULong)

test = alloca (\pStruct -> do
         poke pStruct ( (fromIntegral 1)::CULong, (fromIntegral 1)::CULong )
         )

Thanks for your help.

Marco

[Haskell-beginners] How to initialize a C struct with FFI

Marco De Oliveira