Problematic behavior with preprocessor not showing the actual error

[stefanos82]

I'm working on a simple demo and when I run the code, it returned me this confusing output:

Here's the code:

require 'io'
require 'string'

local FOREGROUND <comptime> = 38
local BACKGROUND <comptime> = 48

local function color_range(first: integer, last, anyground: integer)
  local resetdefault: string = "\x1b[0m"
  local resetwithspace: string = "\x1b[0m "

  local resetoutput = resetwithspace
  for color = first, last do
    if color % 16 == 0 then
      io.printf("\n")
    end
    if color == last then
      resetoutput = resetdefault
    end

    io.printf(string.format("\x1b[%d;5;%dm%3d%s", anyground, color, color, resetoutput))
  end
end

io.printf("\x1b[1;39m0 to 255 Colors (FOREGROUND)\x1b[22;0m\n")
color_range(0, 255, FOREGROUND)
io.printf("\n\n")

io.printf("\x1b[1;39m0 to 255 Colors (BACKGROUND)\x1b[22;0m\n")
color_range(0, 255, BACKGROUND)
io.printf("\n\n")

In case you are wondering what's the catch, it's the darn last; I forgot to declare it as integer and the compiler tried to interpret it as any.

It took me some time disabling my io.printf()s to isolate the behavior.

When a similar issue pops up, what is your suggestion to detect it as soon as possible?

Am I supposed to use a flag or some kind of internal trick to isolate the problematic code?

Can we do something about it @edubart ?