function stringtovec(str)
    parts = {}
    for part in string.gmatch(str,"([^,])") do
        table.insert(parts,part)
    end
    return vector.new(unpack(parts))
end
sf = require("structure")

function removechunks()
    file = fs.open("tobuild","r")
    lines = {}
    line = file.readLine()
    
    while line do
        i = math.mod((i or 0)+1,100)
        if i == 0 then sleep(0.05) end
        xyz = stringtovec(line)
        if not chunkisempty(xyz) then
            table.insert(lines,line)
            print(line)
        end
        line = file.readLine()
    end
    file.close()
    fs.delete("tobuildcopy")
    file = fs.open("tobuildcopy","w")
    for i,line in ipairs(lines) do
        file.writeLine(line)
        print(line)
        if math.mod(i,100) == 0 then sleep(0.05) end
    end
    file.close() 
end
function chunkisempty(vec)
    x,y,z = vec.x,vec.y,vec.z
    for w = 1,8 do
        for h = 1,8 do
            for d = 1,8 do
                bool,block = sf.blockat(x+w,z+d,y+h) 
                if bool then
                    print(block)
                    return false
                end
            end
        end
    end
    return true
end

--print(chunkisempty(vector.new(-150,0,0)))
removechunks()