[Haskell-cafe] Just for a laugh...

[David Roundy]

On Thu, May 31, 2007 at 11:36:54PM +0200, Tomasz Zielonka wrote:
> You can imitate the C++ code using the FFI libraries:
> 
>     import Foreign.Storable
>     import Foreign
>     import Data.Word
>     import Data.Bits
> 
>     getDoubleBits :: Double -> IO String
>     getDoubleBits d = alloca $ \ptr -> do
>         poke ptr d
>         bs <- peekArray (sizeOf d) (castPtr ptr :: Ptr Word8)
>         return . concatMap (concatMap (show . fromEnum) . flip map [7,6..0] . testBit) $ bs
> 
> (I'm not sure this code prints bits in the right order).
> You can generalize this to
>     getStorableBits :: Storable a => a -> IO String

Note also that you can use unsafePerformIO to safely get pure functions
doing both these operations.
-- 
David Roundy
Department of Physics
Oregon State University