base-4.20.0.1: Core data structures and operations
Copyright(c) The University of Glasgow 2001
LicenseBSD-style (see the file libraries/base/LICENSE)
Maintainerlibraries@haskell.org
Stabilitystable
Portabilityportable
Safe HaskellSafe
LanguageHaskell2010

GHC.Bits

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

Documentation

class Eq 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.

Methods

(.&.) :: a -> a -> a infixl 7 Source #

Bitwise "and"

(.|.) :: a -> a -> a infixl 5 Source #

Bitwise "or"

xor :: a -> a -> a infixl 6 Source #

Bitwise "xor"

complement :: a -> a Source #

Reverse all the bits in the argument

shift :: a -> Int -> a infixl 8 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 infixl 8 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.

zeroBits :: a Source #

zeroBits is the value with all bits unset.

The following laws ought to hold (for all valid bit indices n):

This method uses clearBit (bit 0) 0 as its default implementation (which ought to be equivalent to zeroBits for types which possess a 0th bit).

Since: base-4.7.0.0

bit :: Int -> a Source #

bit i is a value with the ith bit set and all other bits clear.

Can be implemented using bitDefault if a is also an instance of Num.

See also zeroBits.

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 #

x `testBit` i is the same as x .&. bit n /= 0

In other words it returns True if the bit at offset @n is set.

Can be implemented using testBitDefault if a is also an instance of Num.

bitSizeMaybe :: a -> Maybe Int Source #

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.

Since: base-4.7.0.0

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.

Default implementation based upon bitSizeMaybe provided since 4.12.0.0.

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 infixl 8 Source #

Shift the argument left by the specified number of bits (which must be non-negative). Some instances may throw an Overflow exception if given a negative input.

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 -> a Source #

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.

Since: base-4.5.0.0

shiftR :: a -> Int -> a infixl 8 Source #

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. Some instances may throw an Overflow exception if given a negative input.

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 -> a Source #

Shift the first argument right by the specified number of bits, which must be non-negative and 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.

Since: base-4.5.0.0

rotateL :: a -> Int -> a infixl 8 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 infixl 8 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.

popCount :: a -> Int Source #

Return the number of set bits in the argument. This number is known as the population count or the Hamming weight.

Can be implemented using popCountDefault if a is also an instance of Num.

Since: base-4.5.0.0

Instances

Instances details
Bits CBool 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CChar 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CInt 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CIntMax 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CIntPtr 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CLLong 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CLong 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CPtrdiff 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CSChar 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CShort 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CSigAtomic 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CSize 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CUChar 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CUInt 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CUIntMax 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CUIntPtr 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CULLong 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CULong 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CUShort 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits CWchar 
Instance details

Defined in GHC.Internal.Foreign.C.Types

Bits IntPtr 
Instance details

Defined in GHC.Internal.Foreign.Ptr

Bits WordPtr 
Instance details

Defined in GHC.Internal.Foreign.Ptr

Bits Int16

Since: base-2.1

Instance details

Defined in GHC.Internal.Int

Bits Int32

Since: base-2.1

Instance details

Defined in GHC.Internal.Int

Bits Int64

Since: base-2.1

Instance details

Defined in GHC.Internal.Int

Bits Int8

Since: base-2.1

Instance details

Defined in GHC.Internal.Int

Bits CBlkCnt 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CBlkSize 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CClockId 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CDev 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CFsBlkCnt 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CFsFilCnt 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CGid 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CId 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CIno 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CKey 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CMode 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CNfds 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CNlink 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits COff 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CPid 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CRLim 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CSocklen 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CSsize 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CTcflag 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits CUid 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits Fd 
Instance details

Defined in GHC.Internal.System.Posix.Types

Bits Word16

Since: base-2.1

Instance details

Defined in GHC.Internal.Word

Bits Word32

Since: base-2.1

Instance details

Defined in GHC.Internal.Word

Bits Word64

Since: base-2.1

Instance details

Defined in GHC.Internal.Word

Bits Word8

Since: base-2.1

Instance details

Defined in GHC.Internal.Word

Bits Integer

Since: base-2.1

Instance details

Defined in GHC.Internal.Bits

Bits Natural

Since: base-4.8.0

Instance details

Defined in GHC.Internal.Bits

Bits Bool

Interpret Bool as 1-bit bit-field

Since: base-4.7.0.0

Instance details

Defined in GHC.Internal.Bits

Bits Int

Since: base-2.1

Instance details

Defined in GHC.Internal.Bits

Bits Word

Since: base-2.1

Instance details

Defined in GHC.Internal.Bits

Bits a => Bits (And a)

Since: base-4.16

Instance details

Defined in GHC.Internal.Data.Bits

Methods

(.&.) :: And a -> And a -> And a Source #

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

xor :: And a -> And a -> And a Source #

complement :: And a -> And a Source #

shift :: And a -> Int -> And a Source #

rotate :: And a -> Int -> And a Source #

zeroBits :: And a Source #

bit :: Int -> And a Source #

setBit :: And a -> Int -> And a Source #

clearBit :: And a -> Int -> And a Source #

complementBit :: And a -> Int -> And a Source #

testBit :: And a -> Int -> Bool Source #

bitSizeMaybe :: And a -> Maybe Int Source #

bitSize :: And a -> Int Source #

isSigned :: And a -> Bool Source #

shiftL :: And a -> Int -> And a Source #

unsafeShiftL :: And a -> Int -> And a Source #

shiftR :: And a -> Int -> And a Source #

unsafeShiftR :: And a -> Int -> And a Source #

rotateL :: And a -> Int -> And a Source #

rotateR :: And a -> Int -> And a Source #

popCount :: And a -> Int Source #

Bits a => Bits (Iff a)

Since: base-4.16

Instance details

Defined in GHC.Internal.Data.Bits

Methods

(.&.) :: Iff a -> Iff a -> Iff a Source #

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

xor :: Iff a -> Iff a -> Iff a Source #

complement :: Iff a -> Iff a Source #

shift :: Iff a -> Int -> Iff a Source #

rotate :: Iff a -> Int -> Iff a Source #

zeroBits :: Iff a Source #

bit :: Int -> Iff a Source #

setBit :: Iff a -> Int -> Iff a Source #

clearBit :: Iff a -> Int -> Iff a Source #

complementBit :: Iff a -> Int -> Iff a Source #

testBit :: Iff a -> Int -> Bool Source #

bitSizeMaybe :: Iff a -> Maybe Int Source #

bitSize :: Iff a -> Int Source #

isSigned :: Iff a -> Bool Source #

shiftL :: Iff a -> Int -> Iff a Source #

unsafeShiftL :: Iff a -> Int -> Iff a Source #

shiftR :: Iff a -> Int -> Iff a Source #

unsafeShiftR :: Iff a -> Int -> Iff a Source #

rotateL :: Iff a -> Int -> Iff a Source #

rotateR :: Iff a -> Int -> Iff a Source #

popCount :: Iff a -> Int Source #

Bits a => Bits (Ior a)

Since: base-4.16

Instance details

Defined in GHC.Internal.Data.Bits

Methods

(.&.) :: Ior a -> Ior a -> Ior a Source #

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

xor :: Ior a -> Ior a -> Ior a Source #

complement :: Ior a -> Ior a Source #

shift :: Ior a -> Int -> Ior a Source #

rotate :: Ior a -> Int -> Ior a Source #

zeroBits :: Ior a Source #

bit :: Int -> Ior a Source #

setBit :: Ior a -> Int -> Ior a Source #

clearBit :: Ior a -> Int -> Ior a Source #

complementBit :: Ior a -> Int -> Ior a Source #

testBit :: Ior a -> Int -> Bool Source #

bitSizeMaybe :: Ior a -> Maybe Int Source #

bitSize :: Ior a -> Int Source #

isSigned :: Ior a -> Bool Source #

shiftL :: Ior a -> Int -> Ior a Source #

unsafeShiftL :: Ior a -> Int -> Ior a Source #

shiftR :: Ior a -> Int -> Ior a Source #

unsafeShiftR :: Ior a -> Int -> Ior a Source #

rotateL :: Ior a -> Int -> Ior a Source #

rotateR :: Ior a -> Int -> Ior a Source #

popCount :: Ior a -> Int Source #

Bits a => Bits (Xor a)

Since: base-4.16

Instance details

Defined in GHC.Internal.Data.Bits

Methods

(.&.) :: Xor a -> Xor a -> Xor a Source #

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

xor :: Xor a -> Xor a -> Xor a Source #

complement :: Xor a -> Xor a Source #

shift :: Xor a -> Int -> Xor a Source #

rotate :: Xor a -> Int -> Xor a Source #

zeroBits :: Xor a Source #

bit :: Int -> Xor a Source #

setBit :: Xor a -> Int -> Xor a Source #

clearBit :: Xor a -> Int -> Xor a Source #

complementBit :: Xor a -> Int -> Xor a Source #

testBit :: Xor a -> Int -> Bool Source #

bitSizeMaybe :: Xor a -> Maybe Int Source #

bitSize :: Xor a -> Int Source #

isSigned :: Xor a -> Bool Source #

shiftL :: Xor a -> Int -> Xor a Source #

unsafeShiftL :: Xor a -> Int -> Xor a Source #

shiftR :: Xor a -> Int -> Xor a Source #

unsafeShiftR :: Xor a -> Int -> Xor a Source #

rotateL :: Xor a -> Int -> Xor a Source #

rotateR :: Xor a -> Int -> Xor a Source #

popCount :: Xor a -> Int Source #

Bits a => Bits (Identity a)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Functor.Identity

Bits a => Bits (Down a)

Since: base-4.14.0.0

Instance details

Defined in GHC.Internal.Data.Ord

Methods

(.&.) :: Down a -> Down a -> Down a Source #

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

xor :: Down a -> Down a -> Down a Source #

complement :: Down a -> Down a Source #

shift :: Down a -> Int -> Down a Source #

rotate :: Down a -> Int -> Down a Source #

zeroBits :: Down a Source #

bit :: Int -> Down a Source #

setBit :: Down a -> Int -> Down a Source #

clearBit :: Down a -> Int -> Down a Source #

complementBit :: Down a -> Int -> Down a Source #

testBit :: Down a -> Int -> Bool Source #

bitSizeMaybe :: Down a -> Maybe Int Source #

bitSize :: Down a -> Int Source #

isSigned :: Down a -> Bool Source #

shiftL :: Down a -> Int -> Down a Source #

unsafeShiftL :: Down a -> Int -> Down a Source #

shiftR :: Down a -> Int -> Down a Source #

unsafeShiftR :: Down a -> Int -> Down a Source #

rotateL :: Down a -> Int -> Down a Source #

rotateR :: Down a -> Int -> Down a Source #

popCount :: Down a -> Int Source #

Bits a => Bits (Const a b)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Functor.Const

Methods

(.&.) :: Const a b -> Const a b -> Const a b Source #

(.|.) :: Const a b -> Const a b -> Const a b Source #

xor :: Const a b -> Const a b -> Const a b Source #

complement :: Const a b -> Const a b Source #

shift :: Const a b -> Int -> Const a b Source #

rotate :: Const a b -> Int -> Const a b Source #

zeroBits :: Const a b Source #

bit :: Int -> Const a b Source #

setBit :: Const a b -> Int -> Const a b Source #

clearBit :: Const a b -> Int -> Const a b Source #

complementBit :: Const a b -> Int -> Const a b Source #

testBit :: Const a b -> Int -> Bool Source #

bitSizeMaybe :: Const a b -> Maybe Int Source #

bitSize :: Const a b -> Int Source #

isSigned :: Const a b -> Bool Source #

shiftL :: Const a b -> Int -> Const a b Source #

unsafeShiftL :: Const a b -> Int -> Const a b Source #

shiftR :: Const a b -> Int -> Const a b Source #

unsafeShiftR :: Const a b -> Int -> Const a b Source #

rotateL :: Const a b -> Int -> Const a b Source #

rotateR :: Const a b -> Int -> Const a b Source #

popCount :: Const a b -> Int Source #

class Bits b => FiniteBits b where Source #

The FiniteBits class denotes types with a finite, fixed number of bits.

Since: base-4.7.0.0

Minimal complete definition

finiteBitSize

Methods

finiteBitSize :: b -> Int Source #

Return the number of bits in the type of the argument. The actual value of the argument is ignored. Moreover, finiteBitSize is total, in contrast to the deprecated bitSize function it replaces.

finiteBitSize = bitSize
bitSizeMaybe = Just . finiteBitSize

Since: base-4.7.0.0

countLeadingZeros :: b -> Int Source #

Count number of zero bits preceding the most significant set bit.

countLeadingZeros (zeroBits :: a) = finiteBitSize (zeroBits :: a)

countLeadingZeros can be used to compute log base 2 via

logBase2 x = finiteBitSize x - 1 - countLeadingZeros x

Note: The default implementation for this method is intentionally naive. However, the instances provided for the primitive integral types are implemented using CPU specific machine instructions.

Since: base-4.8.0.0

countTrailingZeros :: b -> Int Source #

Count number of zero bits following the least significant set bit.

countTrailingZeros (zeroBits :: a) = finiteBitSize (zeroBits :: a)
countTrailingZeros . negate = countTrailingZeros

The related find-first-set operation can be expressed in terms of countTrailingZeros as follows

findFirstSet x = 1 + countTrailingZeros x

Note: The default implementation for this method is intentionally naive. However, the instances provided for the primitive integral types are implemented using CPU specific machine instructions.

Since: base-4.8.0.0

Instances

Instances details
FiniteBits CBool 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CChar 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CInt 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CIntMax 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CIntPtr 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CLLong 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CLong 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CPtrdiff 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CSChar 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CShort 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CSigAtomic 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CSize 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CUChar 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CUInt 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CUIntMax 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CUIntPtr 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CULLong 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CULong 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CUShort 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits CWchar 
Instance details

Defined in GHC.Internal.Foreign.C.Types

FiniteBits IntPtr 
Instance details

Defined in GHC.Internal.Foreign.Ptr

FiniteBits WordPtr 
Instance details

Defined in GHC.Internal.Foreign.Ptr

FiniteBits Int16

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Int

FiniteBits Int32

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Int

FiniteBits Int64

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Int

FiniteBits Int8

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Int

FiniteBits CBlkCnt 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CBlkSize 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CClockId 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CDev 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CFsBlkCnt 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CFsFilCnt 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CGid 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CId 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CIno 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CKey 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CMode 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CNfds 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CNlink 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits COff 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CPid 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CRLim 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CSocklen 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CSsize 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CTcflag 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits CUid 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits Fd 
Instance details

Defined in GHC.Internal.System.Posix.Types

FiniteBits Word16

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Word

FiniteBits Word32

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Word

FiniteBits Word64

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Word

FiniteBits Word8

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Word

FiniteBits Bool

Since: base-4.7.0.0

Instance details

Defined in GHC.Internal.Bits

FiniteBits Int

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Bits

FiniteBits Word

Since: base-4.6.0.0

Instance details

Defined in GHC.Internal.Bits

FiniteBits a => FiniteBits (And a)

Since: base-4.16

Instance details

Defined in GHC.Internal.Data.Bits

FiniteBits a => FiniteBits (Iff a)

Since: base-4.16

Instance details

Defined in GHC.Internal.Data.Bits

FiniteBits a => FiniteBits (Ior a)

Since: base-4.16

Instance details

Defined in GHC.Internal.Data.Bits

FiniteBits a => FiniteBits (Xor a)

Since: base-4.16

Instance details

Defined in GHC.Internal.Data.Bits

FiniteBits a => FiniteBits (Identity a)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Functor.Identity

FiniteBits a => FiniteBits (Down a)

Since: base-4.14.0.0

Instance details

Defined in GHC.Internal.Data.Ord

FiniteBits a => FiniteBits (Const a b)

Since: base-4.9.0.0

Instance details

Defined in GHC.Internal.Data.Functor.Const

bitDefault :: (Bits a, Num a) => Int -> a Source #

Default implementation for bit.

Note that: bitDefault i = 1 shiftL i

Since: base-4.6.0.0

testBitDefault :: (Bits a, Num a) => a -> Int -> Bool Source #

Default implementation for testBit.

Note that: testBitDefault x i = (x .&. bit i) /= 0

Since: base-4.6.0.0

popCountDefault :: (Bits a, Num a) => a -> Int Source #

Default implementation for popCount.

This implementation is intentionally naive. Instances are expected to provide an optimized implementation for their size.

Since: base-4.6.0.0

toIntegralSized :: (Integral a, Integral b, Bits a, Bits b) => a -> Maybe b Source #

Attempt to convert an Integral type a to an Integral type b using the size of the types as measured by Bits methods.

A simpler version of this function is:

toIntegral :: (Integral a, Integral b) => a -> Maybe b
toIntegral x
  | toInteger x == toInteger y = Just y
  | otherwise                  = Nothing
  where
    y = fromIntegral x

This version requires going through Integer, which can be inefficient. However, toIntegralSized is optimized to allow GHC to statically determine the relative type sizes (as measured by bitSizeMaybe and isSigned) and avoid going through Integer for many types. (The implementation uses fromIntegral, which is itself optimized with rules for base types but may go through Integer for some type pairs.)

Since: base-4.8.0.0