gistfile1.txt

14:51 razor@localhost /home/razor % ghc yoba.hs
[1 of 1] Compiling VV               ( yoba.hs, yoba.o )

VV.hs

{-# LANGUAGE ScopedTypeVariables #-}
module VV where
 
import Control.Monad
import Foreign.ForeignPtr.Safe
import Foreign.Storable
import System.IO
import qualified Data.Vector.Storable as U
 
 
loadVector :: forall a. (Num a, Storable a) => String -> IO (U.Vector a)
loadVector name =
    withFile name ReadMode $ \h -> do
        len <- liftM fromIntegral $ hFileSize h
        ptr <- mallocForeignPtrBytes len
        _ <- withForeignPtr ptr $ \p -> hGetBuf h p len
        return $ U.unsafeFromForeignPtr0 ptr (len `div` sizeOf (0 :: a)