max value addition odd behavior (near Infinity)

[phanirithvij]

Note: this is completely unimportant and impractical I am new to FP in general and I read in the docs there is no max int value and I was trying to determine what it is

import gleam/io
import gleam/list
import gleam/int
import gleam/result

pub fn main() {
  let ints = list.range(972, 1023)
  let ints = list.map(ints, fn(x) { int.to_float(x) })

  let part1 = list.fold(ints, 0.0, fn(count, e) { count +. result.unwrap(int.power(2, e), 0.0) })
  io.debug(part1)
  
  let part2 = 
      result.unwrap(int.power(2, 970.0), 0.0) +.
      result.unwrap(int.power(2, 971.0), 0.0)
  io.debug(part2)

  io.debug(
      part1 +.
      result.unwrap(int.power(2, 970.0), 0.0) +.
      result.unwrap(int.power(2, 971.0), 0.0)
  )
  io.debug(
      part1 +.
      result.unwrap(int.power(2, 971.0), 0.0) +.
      result.unwrap(int.power(2, 970.0), 0.0)
  )
  io.debug(
      part1 +.
      part2
  )

  // max value calculate by hand, manual increment till it prints Infinity
  io.debug(1.797693134862315807937289714053034150799341327100378269361737789804449682927647509466490179775e308)
}

The ouput of the above code in the online repl is

1.7976931348623155e+308   // part1
2.9937604643020797e+292   // part2
1.7976931348623157e+308   // ok
Infinity                                        // ?!
Infinity                                        // ??!
1.7976931348623157e+308   // hand calculated

I read the max value depends on system limits, my ram is two 8+8 GB sticks, x86_64 linux, running on firefox.

I am curious why the above ordering matters in 'ok' line but not in the next two lines.

I assumed it was 2^1024 - 1 but I was wrong, 2^1023 + 2^1022 + ... + 2^971 + ?? to do to get/compute the max value?

[lpil]

JavaScript and Erlang have different number implementations. On Erlang ints have no max size, on JS it's a 64bit floating point number.

[phanirithvij]

Ok thanks for the clarification, I will run gleam outside the browser and see.

As for the 64bit max float value there are many discussions, my question about 971 is kind of answered here https://stackoverflow.com/a/39783981/8608146