Lua 5.1 Bitwise Operators

-- needed because the toBinary function returns the bit in a reversed order

local function reverseTable(t)
    local r={};
    for i=#t,1,-1 do
        r[#r+1]=t[i];
    end;
    return r;
end;

-- getBits function get the bits of an integer

local function getBits(int)
    local bits={};
    while(int>0)do
        bit=int%2;
            bits[#bits+1]=bit;
            int=(int-bit)/2;
    end;
    return bits; --the bits are in reversed order ok
end;


-- parse the integers to bits that can get processed

local function parseIntegers(a,b)
    local ba=reverseTable(getBits(a));
    local bb=reverseTable(getBits(b));
    while(#ba<#bb)do        --{{
        ba={0,unpack(ba)};
    end;                        --because the bits need to be of equivalent length
    while(#ba>#bb)do
        bb={0,unpack(bb)};
    end;                    --}}
    return ba,bb;
end;

-- bitwise and

local function band(a,b)
    local resBits={};
    local ba,bb=parseIntegers(a,b);
    for i=1,#ba do
        resBits[#resBits+1]=ba[i]*bb[i];
    end;
    local res=tonumber(table.concat(resBits),2);
    print(res);
end;

-- bitwise or

local function bor(a,b)
    local resBits={};
    local ba,bb=parseIntegers(a,b);
    for i=1,#ba do
        if((ba[i]==1)or(bb[i]==1))then
            resBits[#resBits+1]=1;
        else
            resBits[#resBits+1]=0;
        end;
    end;
    local res=tonumber(table.concat(resBits),2);
    print(res);
end;

-- bitwise xor

local function bxor(a,b)
    local resBits={};
    local ba,bb=parseIntegers(a,b);
    for i=1,#ba do
        if(ba[i]==bb[i])then
            resBits[#resBits+1]=0;
        else
            resBits[#resBits+1]=1;
        end;
    end;
    local res=tonumber(table.concat(resBits),2);
    print(res);
end;

--bitwise not

local function bnot(a)
    a=-a-1;
    print(a);
end