bit Module¶

Since	Origin / Contributor	Maintainer	Source
2014-12-24	https://github.com/LuaDist/bitlib, Zeroday	Zeroday	bit.c

Bit manipulation support, on the integer type used by the Lua VM. On 5.1 this will be 32bit, whereas on 5.3 it may be either 32bit (default) or 64bit if configured for 64bit integers.

bit.arshift()¶

Arithmetic right shift a number equivalent to value >> shift in C.

Syntax¶

bit.arshift(value, shift)

Parameters¶

• value the value to shift
• shift positions to shift

Returns¶

the number shifted right (arithmetically)

bit.band()¶

Bitwise AND, equivalent to val1 & val2 & ... & valn in C.

Syntax¶

bit.band(val1, val2 [, ... valn])

Parameters¶

• val1 first AND argument
• val2 second AND argument
• ...valn ...nth AND argument

Returns¶

the bitwise AND of all the arguments (number)

bit.bit()¶

Generate a number with a 1 bit (used for mask generation). Equivalent to 1 << position in C.

Syntax¶

bit.bit(position)

Parameters¶

position position of the bit that will be set to 1

Returns¶

a number with only one 1 bit at position (the rest are set to 0)

bit.bnot()¶

Bitwise negation, equivalent to `~value in C.

Syntax¶

bit.bnot(value)

Parameters¶

value the number to negate

Returns¶

the bitwise negated value of the number

bit.bor()¶

Bitwise OR, equivalent to val1 | val2 | ... | valn in C.

Syntax¶

bit.bor(val1, val2 [, ... valn])

Parameters¶

• val1 first OR argument.
• val2 second OR argument.
• ...valn ...nth OR argument

Returns¶

the bitwise OR of all the arguments (number)

bit.bxor()¶

Bitwise XOR, equivalent to val1 ^ val2 ^ ... ^ valn in C.

Syntax¶

bit.bxor(val1, val2 [, ... valn])

Parameters¶

• val1 first XOR argument
• val2 second XOR argument
• ...valn ...nth XOR argument

Returns¶

the bitwise XOR of all the arguments (number)

bit.clear()¶

Clear bits in a number.

Syntax¶

bit.clear(value, pos1 [, ... posn])

Parameters¶

• value the base number
• pos1 position of the first bit to clear
• ...posn position of thet nth bit to clear

Returns¶

the number with the bit(s) cleared in the given position(s)

bit.isclear()¶

Test if a given bit is cleared.

Syntax¶

bit.isclear(value, position)

Parameters¶

• value the value to test
• position bit position to test

Returns¶

true if the bit at the given position is 0, false othewise

bit.isset()¶

Test if a given bit is set.

Syntax¶

bit.isset(value, position)

Parameters¶

• value the value to test
• position bit position to test

Returns¶

true if the bit at the given position is 1, false otherwise

bit.lshift()¶

Left-shift a number, equivalent to value << shift in C.

Syntax¶

bit.lshift(value, shift)

Parameters¶

• value the value to shift
• shift positions to shift

Returns¶

the number shifted left

bit.rshift()¶

Logical right shift a number, equivalent to ( unsigned )value >> shift in C.

Syntax¶

bit.rshift(value, shift)

Parameters¶

• value the value to shift.
• shift positions to shift.

Returns¶

the number shifted right (logically)

bit.set()¶

Set bits in a number.

Syntax¶

bit.set(value, pos1 [, ... posn ])

Parameters¶

• value the base number.
• pos1 position of the first bit to set.
• ...posn position of the nth bit to set.

Returns¶

the number with the bit(s) set in the given position(s)