shithub: MicroHs

ref: 8b1254a40b24e0e7a52d94bdcfc91edef57ac53e
dir: /lib/System/Compress.hs/

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module System.Compress(compress) where
import Foreign.C.String
import Foreign.Marshal.Alloc
import Foreign.Marshal.Utils
import Foreign.Ptr
import Foreign.Storable
import System.IO.Unsafe

foreign import ccall "lz77c" c_lz77c :: CString -> Int -> Ptr CString -> IO Int

-- This really ought to be [Word8] -> [Word8]
compress :: String -> String
compress file = unsafePerformIO $ do
  (iptr, ilen) <- newCAStringLen file
  pptr <- new nullPtr
  olen <- c_lz77c iptr ilen pptr
  optr <- peek pptr
  res <- peekCAStringLen (optr, olen)
  free iptr
  free optr
  return res