content: {-# OPTIONS_JHC -fm4 -fno-prelude -fffi  #-}
  module Data.Bits where
  
  
  import Jhc.Num
  import Jhc.Order
  import Jhc.Basics
  import Jhc.Type.C
  
  m4_include(Data/Bits.m4)
  
  
  infixl 8 `shift`, `rotate`, `shiftL`, `shiftR`, `rotateL`, `rotateR`
  infixl 7 .&.
  infixl 6 `xor`
  infixl 5 .|.
  
  
  {-|
  The 'Bits' class defines bitwise operations over integral types.
  
  * Bits are numbered from 0 with bit 0 being the least
    significant bit.
  -}
  class Num a => Bits a where
      -- | Bitwise \"and\"
      (.&.) :: a -> a -> a
  
      -- | Bitwise \"or\"
      (.|.) :: a -> a -> a
  
      -- | Bitwise \"xor\"
      xor :: a -> a -> a
  
      {-| Reverse all the bits in the argument -}
      complement        :: a -> a
  
      {-| Shift the argument left by the specified number of bits.
  	Right shifts (signed) are specified by giving a negative value.
  
  	An instance can define either this unified 'shift' or 'shiftL' and
  	'shiftR', depending on which is more convenient for the type in
  	question. -}
      shift             :: a -> Int -> a
  
      x `shift`   i | i<0  = x `shiftR` (-i)
                    | i==0 = x
                    | i>0  = x `shiftL` i
  
      {-| Rotate the argument left by the specified number of bits.
  	Right rotates are specified by giving a negative value.
  
          For unbounded types like 'Integer', 'rotate' is equivalent to 'shift'.
  
  	An instance can define either this unified 'rotate' or 'rotateL' and
  	'rotateR', depending on which is more convenient for the type in
  	question. -}
      rotate            :: a -> Int -> a
  
      x `rotate`  i | i<0  = x `rotateR` (-i)
                    | i==0 = x
                    | i>0  = x `rotateL` i
  
      {-
      -- Rotation can be implemented in terms of two shifts, but care is
      -- needed for negative values.  This suggested implementation assumes
      -- 2's-complement arithmetic.  It is commented out because it would
      -- require an extra context (Ord a) on the signature of 'rotate'.
      x `rotate`  i | i<0 && isSigned x && x<0
                           = let left = i+bitSize x in
                             ((x `shift` i) .&. complement ((-1) `shift` left))
                             .|. (x `shift` left)
                    | i<0  = (x `shift` i) .|. (x `shift` (i+bitSize x))
                    | i==0 = x
                    | i>0  = (x `shift` i) .|. (x `shift` (i-bitSize x))
      -}
  
      -- | @bit i@ is a value with the @i@th bit set
      bit               :: Int -> a
  
      -- | @x \`setBit\` i@ is the same as @x .|. bit i@
      setBit            :: a -> Int -> a
  
      -- | @x \`clearBit\` i@ is the same as @x .&. complement (bit i)@
      clearBit          :: a -> Int -> a
  
      -- | @x \`complementBit\` i@ is the same as @x \`xor\` bit i@
      complementBit     :: a -> Int -> a
  
      -- | Return 'True' if the @n@th bit of the argument is 1
      testBit           :: a -> Int -> Bool
  
      {-| Return the number of bits in the type of the argument.  The actual
  	value of the argument is ignored.  The function 'bitSize' is
  	undefined for types that do not have a fixed bitsize, like 'Integer'.
  	-}
      bitSize           :: a -> Int
  
      {-| Return 'True' if the argument is a signed type.  The actual
          value of the argument is ignored -}
      isSigned          :: a -> Bool
  
      bit i               = 1 `shiftL` i
      x `setBit` i        = x .|. bit i
      x `clearBit` i      = x .&. complement (bit i)
      x `complementBit` i = x `xor` bit i
      x `testBit` i       = (x .&. bit i) /= 0
  
      {-| Shift the argument left by the specified number of bits
  	(which must be non-negative).
  
  	An instance can define either this and 'shiftR' or the unified
  	'shift', depending on which is more convenient for the type in
  	question. -}
      shiftL            :: a -> Int -> a
      x `shiftL`  i = x `shift`  i
  
      {-| Shift the argument right (signed) by the specified number of bits
  	(which must be non-negative).
  
  	An instance can define either this and 'shiftL' or the unified
  	'shift', depending on which is more convenient for the type in
  	question. -}
      shiftR            :: a -> Int -> a
      x `shiftR`  i = x `shift`  (-i)
  
      {-| Rotate the argument left by the specified number of bits
  	(which must be non-negative).
  
  	An instance can define either this and 'rotateR' or the unified
  	'rotate', depending on which is more convenient for the type in
  	question. -}
      rotateL           :: a -> Int -> a
      x `rotateL` i = x `rotate` i
  
      {-| Rotate the argument right by the specified number of bits
  	(which must be non-negative).
  
  	An instance can define either this and 'rotateL' or the unified
  	'rotate', depending on which is more convenient for the type in
  	question. -}
      rotateR           :: a -> Int -> a
      x `rotateR` i = x `rotate` (-i)
  
  
  
  BITSINST(Int,a)
  BITSINST(Int8,a)
  BITSINST(Int16,a)
  BITSINST(Int32,a)
  BITSINST(Int64,a)
  BITSINST(IntPtr,a)
  BITSINST(IntMax,a)
  BITSINST(Integer,a)
  
  BITSINST(Word)
  BITSINST(Word8)
  BITSINST(Word16)
  BITSINST(Word32)
  BITSINST(Word64)
  BITSINST(WordPtr)
  BITSINST(WordMax)
  
  BITSINST(CChar,a)
  BITSINST(CInt,a)
  BITSINST(CLLong,a)
  BITSINST(CLong,a)
  BITSINST(CSChar,a)
  BITSINST(CSize,a)
  BITSINST(CUChar,a)
  BITSINST(CUInt,a)
  BITSINST(CULLong,a)
  BITSINST(CULong,a)
  BITSINST(CWchar,a)
  