Quoting from Programming in lua:
We can write constants larger than 2^63 -1 directly, despite appearances:
> x = 13835058055282163712 -- 3 << 62
> x
--> -4611686018427387904
When I enter this example into an interpreter (you can try in the lua demo) the number is cast to a float, is that supposed to happen?
I wrote the following helper function(s) to "tonumber" strings which may be UInts, but I was wondering I could do it by a more direct method as discussed in the manual:
local function by10(n, i) i = i or 1
for _ = 1, i do n = (n << 4) - (n << 2) - (n << 1) end
return n
end
function integer(s) s = s:reverse()
local n = 0
for i = 0, #s -1 do
n = n + by10(s:sub(i+1,i+1)|0, i)
end
return n
end
