纯Lua实现的位操作，识货的拿去

标签：纯lua 位操作   位运算   

ZZMathBit = {}

function ZZMathBit.__andBit(left,right)
    return (left == 1 and right == 1) and 1 or 0    
end

function ZZMathBit.__orBit(left, right)
    return (left == 1 or right == 1) and 1 or 0
end

function ZZMathBit.__xorBit(left, right)
    return (left + right) == 1 and 1 or 0
end

function ZZMathBit.__base(left, right, op)
    if left < right then
        left, right = right, left
    end
    local res = 0
    local shift = 1
    while left ~= 0 do
        local ra = left % 2
        local rb = right % 2
        res = shift * op(ra,rb) + res
        shift = shift * 2
        left = math.modf( left / 2)
        right = math.modf( right / 2)
    end
    return res
end

function ZZMathBit.andOp(left, right)
    return ZZMathBit.__base(left, right, ZZMathBit.__andBit)
end

function ZZMathBit.xorOp(left, right)
    return ZZMathBit.__base(left, right, ZZMathBit.__xorBit)
end

function ZZMathBit.orOp(left, right)
    return ZZMathBit.__base(left, right, ZZMathBit.__orBit)
end

function ZZMathBit.notOp(left)
    return left > 0 and -(left + 1) or -left - 1 
end

function ZZMathBit.lShiftOp(left, num)
    return left * (2 ^ num)
end

function ZZMathBit.rShiftOp(left,num)
    return math.floor(left / (2 ^ num))
end

function ZZMathBit.test()
    print( ZZMathBit.andOp(65,0x3f))
    print(65 % 64)
    print( ZZMathBit.orOp(5678,6789))
    print( ZZMathBit.xorOp(13579,2468))
    print( ZZMathBit.rShiftOp(16,3))
    print( ZZMathBit.notOp(-4))

    print(string.byte("abc",1))
end

ZZMathBit.test()

纯Lua实现的位操作，识货的拿去

标签：纯lua 位操作   位运算   

原文地址：http://blog.csdn.net/jxnczyp/article/details/43588719