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module Bug where
import Foreign hiding ( unsafePerformIO )
import Foreign.ForeignPtr
import Data.Char
import System.IO.Unsafe
data PackedString = PS !(ForeignPtr Word8) !Int !Int
(!) :: PackedString -> Int -> Word8
(PS x s _l) ! i
= unsafePerformIO $ withForeignPtr x $ \p -> peekElemOff p (s+i)
w2c :: Word8 -> Char
w2c = chr . fromIntegral
indexPS :: PackedString -> Int -> Char
indexPS theps i | i < 0 = error "Negative index in indexPS"
| otherwise = w2c $ theps ! i
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