Lua 5.5 incompatibility with the variable in the for loop now being constant

[davebellows]

I just updated to Lua 5.5 and ran into multiple instances of the same problem where the loop variable of a FOR statement is modified. This isn't allowed in Lua 5.5 as the loop variable in the FOR loop is now a constant. Here is an example from around line 251:

for y = 0, 127 * 256, 256 do
   for x = y, y + 127 do
      x = AND_of_two_bytes[x] * 2
      AND_of_two_bytes[idx] = x
      AND_of_two_bytes[idx + 1] = x
      AND_of_two_bytes[idx + 256] = x
      AND_of_two_bytes[idx + 257] = x + 1
      idx = idx + 2
   end
   idx = idx + 256
end

So the third line "x = AND_of_two_bytes[x] * 2" is the problem. The error message reads:

attempt to assign to const variable 'x'

This same problem happens again many more times with lines in the form of:

pos = pos + 4 -- or + 8

There might be more such examples but that's what I found.

I'm not much of a programmer at all but use this module extensively in a project and have no idea how to fix it myself.