| Copyright | (c) The University of Glasgow 2001 |
|---|---|
| License | (c) The University of Glasgow 2001 |
| Maintainer | libraries@haskell.org |
| Stability | experimental |
| Portability | portable |
| Safe Haskell | Trustworthy |
Data.Bits
Description
- class Eq 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
- bitSizeMaybe :: a -> Maybe Int
- bitSize :: a -> Int
- isSigned :: a -> Bool
- shiftL :: a -> Int -> a
- unsafeShiftL :: a -> Int -> a
- shiftR :: a -> Int -> a
- unsafeShiftR :: a -> Int -> a
- rotateL :: a -> Int -> a
- rotateR :: a -> Int -> a
- popCount :: a -> Int
- class Bits b => FiniteBits b where
- finiteBitSize :: b -> Int
- bitDefault :: (Bits a, Num a) => Int -> a
- testBitDefault :: (Bits a, Num a) => a -> Int -> Bool
- popCountDefault :: (Bits a, Num a) => a -> Int
Documentation
class Eq a => Bits a whereSource
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, isSigned, testBit, bit, and popCount. The latter three can
be implemented using testBitDefault, 'bitDefault, and popCountDefault, if
a is also an instance of Num.
Methods
Bitwise "and"
Bitwise "or"
Bitwise "xor"
complement :: a -> aSource
Reverse all the bits in the argument
shift x ix 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 x ix 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 i is a value with the ith bit set and all other bits clear
x `setBit` i is the same as x .|. bit i
clearBit :: a -> Int -> aSource
x `clearBit` i is the same as x .&. complement (bit i)
complementBit :: a -> Int -> aSource
x `complementBit` i is the same as x `xor` bit i
testBit :: a -> Int -> BoolSource
Return True if the nth bit of the argument is 1
bitSizeMaybe :: a -> Maybe IntSource
Return the number of bits in the type of the argument. The actual
value of the argument is ignored. Returns Nothing
for types that do not have a fixed bitsize, like Integer.
Deprecated: Use bitSizeMaybe or finiteBitSize instead
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.
Return True if the argument is a signed type. The actual
value of the argument is ignored
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.
unsafeShiftL :: a -> Int -> aSource
Shift the argument left by the specified number of bits. The
result is undefined for negative shift amounts and shift amounts
greater or equal to the bitSize.
Defaults to shiftL unless defined explicitly by an instance.
Shift the first argument right by the specified number of bits. The
result is undefined for negative shift amounts and shift amounts
greater or equal to the bitSize.
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.
unsafeShiftR :: a -> Int -> aSource
Shift the first argument right by the specified number of bits, which must be non-negative an smaller than the number of bits in the type.
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.
Defaults to shiftR unless defined explicitly by an instance.
rotateL :: a -> Int -> aSource
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 -> aSource
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.
Return the number of set bits in the argument. This number is known as the population count or the Hamming weight.
Instances
class Bits b => FiniteBits b whereSource
Methods
finiteBitSize :: b -> IntSource
bitDefault :: (Bits a, Num a) => Int -> aSource