BrainFuck Gen

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local byte, len, char, sub = string.byte, string.len, string.char, string.sub
local floor, log10, ceil = math.floor, math.log10, math.ceil
local concat = table.concat

local function numbs(number) -- math.numbs
  return floor(log10(number)) + 1
end

local function first(number, numeral) -- math.first
  numeral = numeral or 1
  local numbs = numbs(number)
  return floor(number / ( 10 ^ ( numbs - numeral ) ))
end

local function last(number, numeral) -- math.last
  numeral = numeral or 1
  return number % ( 10 ^ numeral )
end

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local function get_numb(char)
  local a = first(char, numbs(char) - 1)
  local b = last(char)
  if b > 5 then a = a + 1 end
  return a
end

local function find_table_value(tab, value)
  for i = 1, #tab do
    if tab[i] == value then return i end
  end
end

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local params, chars = {}, {}

if not _ARGS then return end
local text = { _ARGS }
local ret = '++++++++++['

local h, l = 0, 0

text = Utf8ToAnsi(concat(text, ' '))

for i = 1, #text do
  local ch = byte(text, i)
  local a = get_numb(ch)
  if not find_table_value(params, a) then
    params[#params + 1] = a
  end
end

for i = 1, #params do
  h = h + 1
  ret = ret .. '>'
  for l = 1, params[i] do ret = ret .. '+' end
end

for i = 1, h do
  ret = ret .. '<'
end

ret = ret .. '-]'

for i = 1, #text do
  local ch = byte(text, i)
  local a = get_numb(ch)
  local m = find_table_value(params, a)
  if m then
    if not chars[m] then chars[m] = a end
    while l ~= m do
      if l > m then
        l = l - 1
        ret = ret .. '<'
      elseif l < m then
        l = l + 1
        ret = ret ..'>'
      end
    end
    local d = chars[m] * 10
    while d ~= ch do
      if d > ch then
        d = d - 1
        ret = ret .. '-'
      elseif d < ch then
        d = d + 1
        ret = ret .. '+'
      end
    end
    chars[m] = d / 10
    ret = ret .. '.'
  end
end

return ret