So to be clear, it’s not as if the language is removing negative indexing altogether, it’s just that the built in collections will not support them.
Maybe we could have a different collection like a loop, which is like a list but supports indexing in both directions. Then on the “box” put a disclaimer about the performance cost when using in a gpu.
Also at compile time if negative indexes are detected that we get the recommendation to use the other collection which supports negative indexing.