Promise.all() result ordering is non-deterministic

[Qard]

It'd be nice if Promise.all() had deterministic result ordering. Currently the result array is ordered by completion time not by position of associated promise in the input array. This is different from how JavaScript promises work, which maintain array position between input and output lists.

Here's an example of the issue:

promises = [] of Promise(Int32 | Nil)
10.times do |i|
  promises << Promise(Int32 | Nil).execute do
    sleep 10 - i
    i
  end
end
Promise(Int32 | Nil).all(promises)
  .then { |result| p result }
  .catch { |ex| puts ex.message }
  .await

This will not print [0,1,2,3,4,5,6,7,8,9] like one would expect, it will instead print [9,8,7,6,5,4,3,2,1,0]. If you change the sleep 10 - i to read sleep i it will result in a matching order due to the increasing sleep time.