content: {-# LANGUAGE Safe #-}
  {-# LANGUAGE NoImplicitPrelude #-}
  
  -----------------------------------------------------------------------------
  -- |
  -- Module      :  Data.Word
  -- Copyright   :  (c) The University of Glasgow 2001
  -- License     :  BSD-style (see the file libraries/base/LICENSE)
  --
  -- Maintainer  :  libraries@haskell.org
  -- Stability   :  experimental
  -- Portability :  portable
  --
  -- Unsigned integer types.
  --
  -----------------------------------------------------------------------------
  
  module Data.Word
    (
          -- * Unsigned integral types
  
          Word,
          Word8, Word16, Word32, Word64,
  
          -- * byte swapping
          byteSwap16, byteSwap32, byteSwap64,
  
          -- * Notes
  
          -- $notes
          ) where
  
  import GHC.Word
  import GHC.Read () -- Need the `Read` instance for types defined in `GHC.Word`.
  
  {- $notes
  
  * All arithmetic is performed modulo 2^n, where n is the number of
    bits in the type.  One non-obvious consequence of this is that 'Prelude.negate'
    should /not/ raise an error on negative arguments.
  
  * For coercing between any two integer types, use
    'Prelude.fromIntegral', which is specialized for all the
    common cases so should be fast enough.  Coercing word types to and
    from integer types preserves representation, not sign.
  
  * An unbounded size unsigned integer type is available with
    'Numeric.Natural.Natural'.
  
  * The rules that hold for 'Prelude.Enum' instances over a bounded type
    such as 'Prelude.Int' (see the section of the Haskell report dealing
    with arithmetic sequences) also hold for the 'Prelude.Enum' instances
    over the various 'Word' types defined here.
  
  * Right and left shifts by amounts greater than or equal to the width
    of the type result in a zero result.  This is contrary to the
    behaviour in C, which is undefined; a common interpretation is to
    truncate the shift count to the width of the type, for example @1 \<\<
    32 == 1@ in some C implementations.
  -}
  