--[[
Description:
FileName:bit.lua
This module provides a selection of bitwise operations.
History:
Initial version created by 陣雨 2005-11-10.
Notes:
....
]]
--[[{2147483648,1073741824,536870912,268435456,134217728,67108864,33554432,16777216,
8388608,4194304,2097152,1048576,524288,262144,131072,65536,
32768,16384,8192,4096,2048,1024,512,256,128,64,32,16,8,4,2,1}
]]
bit={data32={}}
for i=1,32 do
bit.data32[i]=2^(32-i)
end
function bit:d2b(arg)
local tr={}
for i=1,32 do
if arg >= self.data32[i] then
tr[i]=1
arg=arg-self.data32[i]
else
tr[i]=0
end
end
return tr
end --bit:d2b
function bit:b2d(arg)
local nr=0
for i=1,32 do
if arg[i] ==1 then
nr=nr+2^(32-i)
end
end
return nr
end --bit:b2d
function bit:_xor(a,b)
local op1=self:d2b(a)
local op2=self:d2b(b)
local r={}
for i=1,32 do
if op1[i]==op2[i] then
r[i]=0
else
r[i]=1
end
end
return self:b2d(r)
end --bit:xor
function bit:_and(a,b)
local op1=self:d2b(a)
local op2=self:d2b(b)
local r={}
for i=1,32 do
if op1[i]==1 and op2[i]==1 then
r[i]=1
else
r[i]=0
end
end
return self:b2d(r)
end --bit:_and
function bit:_or(a,b)
local op1=self:d2b(a)
local op2=self:d2b(b)
local r={}
for i=1,32 do
if op1[i]==1 or op2[i]==1 then
r[i]=1
else
r[i]=0
end
end
return self:b2d(r)
end --bit:_or
function bit:_not(a)
local op1=self:d2b(a)
local r={}
for i=1,32 do
if op1[i]==1 then
r[i]=0
else
r[i]=1
end
end
return self:b2d(r)
end --bit:_not
function bit:_rshift(a,n)
local op1=self:d2b(a)
local r=self:d2b(0)
if n < 32 and n > 0 then
for i=1,n do
for i=31,1,-1 do
op1[i+1]=op1[i]
end
op1[1]=0
end
r=op1
end
return self:b2d(r)
end --bit:_rshift
function bit:_lshift(a,n)
local op1=self:d2b(a)
local r=self:d2b(0)
if n < 32 and n > 0 then
for i=1,n do
for i=1,31 do
op1[i]=op1[i+1]
end
op1[32]=0
end
r=op1
end
return self:b2d(r)
end --bit:_lshift
function bit:print(ta)
local sr=""
for i=1,32 do
sr=sr..ta[i]
end
print(sr)
end
bs=bit:d2b(7)
bit:print(bs)
-->00000000000000000000000000000111
bit:print(bit:d2b(bit:_not(7)))
-->11111111111111111111111111111000
bit:print(bit:d2b(bit:_rshift(7,2)))
-->00000000000000000000000000000001
bit:print(bit:d2b(bit:_lshift(7,2)))
-->00000000000000000000000000011100
print(bit:b2d(bs)) --> 7
print(bit:_xor(7,2)) --> 5
print(bit:_and(7,4)) --> 4
print(bit:_or(5,2)) --> 7
--end of bit.lua
posted on 2005-11-11 03:08
陣雨 閱讀(15227)
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Lua Programming