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Data.Bits

Portability | portable
Stability | experimental
Maintainer | libraries@haskell.org

Description
This module defines bitwise operations for signed and unsigned integers. Instances of the class `Bits` for the `Int` and `Integer` types are available from this module, and instances for explicitly sized integral types are available from the Data.Int and Data.Word modules.
Synopsis

class Num a => Bits a where

(.&.) :: a -> a -> a
(.|.) :: a -> a -> a
xor :: a -> a -> a
complement :: a -> a
shift :: a -> Int -> a
rotate :: a -> Int -> a
bit :: Int -> a
setBit :: a -> Int -> a
clearBit :: a -> Int -> a
complementBit :: a -> Int -> a
testBit :: a -> Int -> Bool
bitSize :: a -> Int
isSigned :: a -> Bool
shiftL :: a -> Int -> a
shiftR :: a -> Int -> a
rotateL :: a -> Int -> a
rotateR :: a -> Int -> a

Documentation

class Num a => Bits a where | Source

The `Bits` class defines bitwise operations over integral types.

- Bits are numbered from 0 with bit 0 being the least significant bit.

Minimal complete definition: `.&.`, `.|.`, `xor`, `complement`, (`shift` or (`shiftL` and `shiftR`)), (`rotate` or (`rotateL` and `rotateR`)), `bitSize` and `isSigned`.

Methods

(.&.) :: a -> a -> a | Source

Bitwise "and"

(.|.) :: a -> a -> a | Source

Bitwise "or"

xor :: a -> a -> a | Source

Bitwise "xor"

complement :: a -> a | Source

Reverse all the bits in the argument

shift :: a -> Int -> a | Source

``shift` x i` shifts `x` left by `i` bits if `i` is positive, or right by `-i` bits otherwise. Right shifts perform sign extension on signed number types; i.e. they fill the top bits with 1 if the `x` is negative and with 0 otherwise. An instance can define either this unified `shift` or `shiftL` and `shiftR`, depending on which is more convenient for the type in question.

rotate :: a -> Int -> a | Source

``rotate` x i` rotates `x` left by `i` bits if `i` is positive, or right by `-i` bits otherwise. 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.

bit :: Int -> a | Source

`bit i` is a value with the `i`th bit set

setBit :: a -> Int -> a | Source

`x `setBit` i` is the same as `x .|. bit i`

clearBit :: a -> Int -> a | Source

`x `clearBit` i` is the same as `x .&. complement (bit i)`

complementBit :: a -> Int -> a | Source

`x `complementBit` i` is the same as `x `xor` bit i`

testBit :: a -> Int -> Bool | Source

Return `True` if the `n`th bit of the argument is 1

bitSize :: a -> Int | Source

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`.

isSigned :: a -> Bool | Source

Return `True` if the argument is a signed type. The actual value of the argument is ignored

shiftL :: a -> Int -> a | Source

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.

shiftR :: a -> Int -> a | Source

Shift the first argument right by the specified number of bits (which must be non-negative). Right shifts perform sign extension on signed number types; i.e. they fill the top bits with 1 if the `x` is negative and with 0 otherwise. An instance can define either this and `shiftL` or the unified `shift`, depending on which is more convenient for the type in question.

rotateL :: a -> Int -> a | Source

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.

rotateR :: a -> Int -> a | Source

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.

Instances

Bits CChar
Bits CGid
Bits CIno
Bits CInt
Bits CIntMax
Bits CIntPtr
Bits CLLong
Bits CLong
Bits CMode
Bits CNlink
Bits COff
Bits CPid
Bits CPtrdiff
Bits CRLim
Bits CSChar
Bits CShort
Bits CSigAtomic
Bits CSize
Bits CSsize
Bits CTcflag
Bits CUChar
Bits CUInt
Bits CUIntMax
Bits CUIntPtr
Bits CULLong
Bits CULong
Bits CUShort
Bits CUid
Bits CWchar
Bits Fd
Bits Int
Bits Int16
Bits Int32
Bits Int64
Bits Int8
Bits IntPtr
Bits Integer
Bits Word
Bits Word16
Bits Word32
Bits Word64
Bits Word8
Bits WordPtr

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