모듈:Bitwise
이 모듈에 대한 설명문서는 모듈:Bitwise/설명문서에서 만들 수 있습니다
--[[
LUA MODULE
bit.numberlua - Bitwise operations implemented in pure Lua as numbers,
with Lua 5.2 'bit32' and (LuaJIT) LuaBitOp 'bit' compatibility interfaces.
SYNOPSIS
local bit = require 'bit.numberlua'
print(bit.band(0xff00ff00, 0x00ff00ff)) --> 0xffffffff
-- Interface providing strong Lua 5.2 'bit32' compatibility
local bit32 = require 'bit.numberlua'.bit32
assert(bit32.band(-1) == 0xffffffff)
-- Interface providing strong (LuaJIT) LuaBitOp 'bit' compatibility
local bit = require 'bit.numberlua'.bit
assert(bit.tobit(0xffffffff) == -1)
DESCRIPTION
This library implements bitwise operations entirely in Lua.
This module is typically intended if for some reasons you don't want
to or cannot install a popular C based bit library like BitOp 'bit' [1]
(which comes pre-installed with LuaJIT) or 'bit32' (which comes
pre-installed with Lua 5.2) but want a similar interface.
This modules represents bit arrays as non-negative Lua numbers. [1]
It can represent 32-bit bit arrays when Lua is compiled
with lua_Number as double-precision IEEE 754 floating point.
The module is nearly the most efficient it can be but may be a few times
slower than the C based bit libraries and is orders or magnitude
slower than LuaJIT bit operations, which compile to native code. Therefore,
this library is inferior in performane to the other modules.
The `xor` function in this module is based partly on Roberto Ierusalimschy's
post in http://lua-users.org/lists/lua-l/2002-09/msg00134.html .
The included BIT.bit32 and BIT.bit sublibraries aims to provide 100%
compatibility with the Lua 5.2 "bit32" and (LuaJIT) LuaBitOp "bit" library.
This compatbility is at the cost of some efficiency since inputted
numbers are normalized and more general forms (e.g. multi-argument
bitwise operators) are supported.
STATUS
WARNING: Not all corner cases have been tested and documented.
Some attempt was made to make these similar to the Lua 5.2 [2]
and LuaJit BitOp [3] libraries, but this is not fully tested and there
are currently some differences. Addressing these differences may
be improved in the future but it is not yet fully determined how to
resolve these differences.
The BIT.bit32 library passes the Lua 5.2 test suite (bitwise.lua)
http://www.lua.org/tests/5.2/ . The BIT.bit library passes the LuaBitOp
test suite (bittest.lua). However, these have not been tested on
platforms with Lua compiled with 32-bit integer numbers.
API
BIT.tobit(x) --> z
Similar to function in BitOp.
BIT.tohex(x, n)
Similar to function in BitOp.
BIT.band(x, y) --> z
Similar to function in Lua 5.2 and BitOp but requires two arguments.
BIT.bor(x, y) --> z
Similar to function in Lua 5.2 and BitOp but requires two arguments.
BIT.bxor(x, y) --> z
Similar to function in Lua 5.2 and BitOp but requires two arguments.
BIT.bnot(x) --> z
Similar to function in Lua 5.2 and BitOp.
BIT.lshift(x, disp) --> z
Similar to function in Lua 5.2 (warning: BitOp uses unsigned lower 5 bits of shift),
BIT.rshift(x, disp) --> z
Similar to function in Lua 5.2 (warning: BitOp uses unsigned lower 5 bits of shift),
BIT.extract(x, field [, width]) --> z
Similar to function in Lua 5.2.
BIT.replace(x, v, field, width) --> z
Similar to function in Lua 5.2.
BIT.bswap(x) --> z
Similar to function in Lua 5.2.
BIT.rrotate(x, disp) --> z
BIT.ror(x, disp) --> z
Similar to function in Lua 5.2 and BitOp.
BIT.lrotate(x, disp) --> z
BIT.rol(x, disp) --> z
Similar to function in Lua 5.2 and BitOp.
BIT.arshift
Similar to function in Lua 5.2 and BitOp.
BIT.btest
Similar to function in Lua 5.2 with requires two arguments.
BIT.bit32
This table contains functions that aim to provide 100% compatibility
with the Lua 5.2 "bit32" library.
bit32.arshift (x, disp) --> z
bit32.band (...) --> z
bit32.bnot (x) --> z
bit32.bor (...) --> z
bit32.btest (...) --> true | false
bit32.bxor (...) --> z
bit32.extract (x, field [, width]) --> z
bit32.replace (x, v, field [, width]) --> z
bit32.lrotate (x, disp) --> z
bit32.lshift (x, disp) --> z
bit32.rrotate (x, disp) --> z
bit32.rshift (x, disp) --> z
BIT.bit
This table contains functions that aim to provide 100% compatibility
with the LuaBitOp "bit" library (from LuaJIT).
bit.tobit(x) --> y
bit.tohex(x [,n]) --> y
bit.bnot(x) --> y
bit.bor(x1 [,x2...]) --> y
bit.band(x1 [,x2...]) --> y
bit.bxor(x1 [,x2...]) --> y
bit.lshift(x, n) --> y
bit.rshift(x, n) --> y
bit.arshift(x, n) --> y
bit.rol(x, n) --> y
bit.ror(x, n) --> y
bit.bswap(x) --> y
DEPENDENCIES
None (other than Lua 5.1 or 5.2).
DOWNLOAD/INSTALLATION
If using LuaRocks:
luarocks install lua-bit-numberlua
Otherwise, download <https://github.com/davidm/lua-bit-numberlua/zipball/master>.
Alternately, if using git:
git clone git://github.com/davidm/lua-bit-numberlua.git
cd lua-bit-numberlua
Optionally unpack:
./util.mk
or unpack and install in LuaRocks:
./util.mk install
REFERENCES
[1] http://lua-users.org/wiki/FloatingPoint
[2] http://www.lua.org/manual/5.2/
[3] http://bitop.luajit.org/
LICENSE
(c) 2008-2011 David Manura. Licensed under the same terms as Lua (MIT).
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
(end license)
--]]
local M = {_TYPE='module', _NAME='bit.numberlua', _VERSION='0.3.1.20120131'}
local floor = math.floor
local MOD = 2^32
local MODM = MOD-1
local function memoize(f)
local mt = {}
local t = setmetatable({}, mt)
function mt:__index(k)
local v = f(k); t[k] = v
return v
end
return t
end
local function make_bitop_uncached(t, m)
local function bitop(a, b)
local res,p = 0,1
while a ~= 0 and b ~= 0 do
local am, bm = a%m, b%m
res = res + t[am][bm]*p
a = (a - am) / m
b = (b - bm) / m
p = p*m
end
res = res + (a+b)*p
return res
end
return bitop
end
local function make_bitop(t)
local op1 = make_bitop_uncached(t,2^1)
local op2 = memoize(function(a)
return memoize(function(b)
return op1(a, b)
end)
end)
return make_bitop_uncached(op2, 2^(t.n or 1))
end
-- ok? probably not if running on a 32-bit int Lua number type platform
function M.tobit(x)
return x % 2^32
end
M.bxor = make_bitop {[0]={[0]=0,[1]=1},[1]={[0]=1,[1]=0}, n=4}
local bxor = M.bxor
function M.bnot(a) return MODM - a end
local bnot = M.bnot
function M.band(a,b) return ((a+b) - bxor(a,b))/2 end
local band = M.band
function M.bor(a,b) return MODM - band(MODM - a, MODM - b) end
local bor = M.bor
local lshift, rshift -- forward declare
function M.rshift(a,disp) -- Lua5.2 insipred
if disp < 0 then return lshift(a,-disp) end
return floor(a % 2^32 / 2^disp)
end
rshift = M.rshift
function M.lshift(a,disp) -- Lua5.2 inspired
if disp < 0 then return rshift(a,-disp) end
return (a * 2^disp) % 2^32
end
lshift = M.lshift
function M.tohex(x, n) -- BitOp style
n = n or 8
local up
if n <= 0 then
if n == 0 then return '' end
up = true
n = - n
end
x = band(x, 16^n-1)
return ('%0'..n..(up and 'X' or 'x')):format(x)
end
local tohex = M.tohex
function M.extract(n, field, width) -- Lua5.2 inspired
width = width or 1
return band(rshift(n, field), 2^width-1)
end
local extract = M.extract
function M.replace(n, v, field, width) -- Lua5.2 inspired
width = width or 1
local mask1 = 2^width-1
v = band(v, mask1) -- required by spec?
local mask = bnot(lshift(mask1, field))
return band(n, mask) + lshift(v, field)
end
local replace = M.replace
function M.bswap(x) -- BitOp style
local a = band(x, 0xff); x = rshift(x, 8)
local b = band(x, 0xff); x = rshift(x, 8)
local c = band(x, 0xff); x = rshift(x, 8)
local d = band(x, 0xff)
return lshift(lshift(lshift(a, 8) + b, 8) + c, 8) + d
end
local bswap = M.bswap
function M.rrotate(x, disp) -- Lua5.2 inspired
disp = disp % 32
local low = band(x, 2^disp-1)
return rshift(x, disp) + lshift(low, 32-disp)
end
local rrotate = M.rrotate
function M.lrotate(x, disp) -- Lua5.2 inspired
return rrotate(x, -disp)
end
local lrotate = M.lrotate
M.rol = M.lrotate -- LuaOp inspired
M.ror = M.rrotate -- LuaOp insipred
function M.arshift(x, disp) -- Lua5.2 inspired
local z = rshift(x, disp)
if x >= 0x80000000 then z = z + lshift(2^disp-1, 32-disp) end
return z
end
local arshift = M.arshift
function M.btest(x, y) -- Lua5.2 inspired
return band(x, y) ~= 0
end
--
-- Start Lua 5.2 "bit32" compat section.
--
M.bit32 = {} -- Lua 5.2 'bit32' compatibility
local function bit32_bnot(x)
return (-1 - x) % MOD
end
M.bit32.bnot = bit32_bnot
local function bit32_bxor(a, b, c, ...)
local z
if b then
a = a % MOD
b = b % MOD
z = bxor(a, b)
if c then
z = bit32_bxor(z, c, ...)
end
return z
elseif a then
return a % MOD
else
return 0
end
end
M.bit32.bxor = bit32_bxor
local function bit32_band(a, b, c, ...)
local z
if b then
a = a % MOD
b = b % MOD
z = ((a+b) - bxor(a,b)) / 2
if c then
z = bit32_band(z, c, ...)
end
return z
elseif a then
return a % MOD
else
return MODM
end
end
M.bit32.band = bit32_band
local function bit32_bor(a, b, c, ...)
local z
if b then
a = a % MOD
b = b % MOD
z = MODM - band(MODM - a, MODM - b)
if c then
z = bit32_bor(z, c, ...)
end
return z
elseif a then
return a % MOD
else
return 0
end
end
M.bit32.bor = bit32_bor
function M.bit32.btest(...)
return bit32_band(...) ~= 0
end
function M.bit32.lrotate(x, disp)
return lrotate(x % MOD, disp)
end
function M.bit32.rrotate(x, disp)
return rrotate(x % MOD, disp)
end
function M.bit32.lshift(x,disp)
if disp > 31 or disp < -31 then return 0 end
return lshift(x % MOD, disp)
end
function M.bit32.rshift(x,disp)
if disp > 31 or disp < -31 then return 0 end
return rshift(x % MOD, disp)
end
function M.bit32.arshift(x,disp)
x = x % MOD
if disp >= 0 then
if disp > 31 then
return (x >= 0x80000000) and MODM or 0
else
local z = rshift(x, disp)
if x >= 0x80000000 then z = z + lshift(2^disp-1, 32-disp) end
return z
end
else
return lshift(x, -disp)
end
end
function M.bit32.extract(x, field, ...)
local width = ... or 1
if field < 0 or field > 31 or width < 0 or field+width > 32 then error 'out of range' end
x = x % MOD
return extract(x, field, ...)
end
function M.bit32.replace(x, v, field, ...)
local width = ... or 1
if field < 0 or field > 31 or width < 0 or field+width > 32 then error 'out of range' end
x = x % MOD
v = v % MOD
return replace(x, v, field, ...)
end
--
-- Start LuaBitOp "bit" compat section.
--
M.bit = {} -- LuaBitOp "bit" compatibility
function M.bit.tobit(x)
x = x % MOD
if x >= 0x80000000 then x = x - MOD end
return x
end
local bit_tobit = M.bit.tobit
function M.bit.tohex(x, ...)
return tohex(x % MOD, ...)
end
function M.bit.bnot(x)
return bit_tobit(bnot(x % MOD))
end
local function bit_bor(a, b, c, ...)
if c then
return bit_bor(bit_bor(a, b), c, ...)
elseif b then
return bit_tobit(bor(a % MOD, b % MOD))
else
return bit_tobit(a)
end
end
M.bit.bor = bit_bor
local function bit_band(a, b, c, ...)
if c then
return bit_band(bit_band(a, b), c, ...)
elseif b then
return bit_tobit(band(a % MOD, b % MOD))
else
return bit_tobit(a)
end
end
M.bit.band = bit_band
local function bit_bxor(a, b, c, ...)
if c then
return bit_bxor(bit_bxor(a, b), c, ...)
elseif b then
return bit_tobit(bxor(a % MOD, b % MOD))
else
return bit_tobit(a)
end
end
M.bit.bxor = bit_bxor
function M.bit.lshift(x, n)
return bit_tobit(lshift(x % MOD, n % 32))
end
function M.bit.rshift(x, n)
return bit_tobit(rshift(x % MOD, n % 32))
end
function M.bit.arshift(x, n)
return bit_tobit(arshift(x % MOD, n % 32))
end
function M.bit.rol(x, n)
return bit_tobit(lrotate(x % MOD, n % 32))
end
function M.bit.ror(x, n)
return bit_tobit(rrotate(x % MOD, n % 32))
end
function M.bit.bswap(x)
return bit_tobit(bswap(x % MOD))
end
return M