brainfuck to Lua

arg = {...}
local path = arg[1]
local input = arg[2]
local readfile = fs.open(input,"r")
local B = readfile.readAll()
readfile.close()
local file = fs.open(path,"w")
local D = {}
local j = 1
repeat
   D[j] = B:sub(j,j)
   j = j + 1
until j == #B+1
local function parse(n)
   if D[n] ~= nil then
      return D[n]
   else
      file.close()
      error("DONE!")
   end
end
local T = {}
T["<"] = "p = p - 1"
T[">"] = "p = p + 1"
T["+"] = "a[p] = a[p] or 0\na[p] = a[p] + 1"
T["-"] = "a[p] = a[p] or 0\na[p] = a[p] - 1"
T["."] = "print(a[p] or 0)"
T[","] = "a[p] = read()"
T["["] = "a[p] = a[p] or 0\nwhile a[p] ~= 0 do"
T["]"] = "end"
local function translate(BF)
   if T[BF] then
      return T[BF]
   end
   return "--Invalid character"
end
local function writeFile(num)
   file.writeLine(translate(parse(num)))
end
file.writeLine("local a = {}\nlocal p = 1\nlocal i = 1\n--repeat\n--a[i] = 0\n--i = i + 1\n--until i == 16384")
local comn = 1
while true do
   writeFile(comn)
   comn = comn + 1
end