Feature Request: Unsigned Integers

[hwayne]

When you specify the integer bitwidth in alloy, it always gives you signed integers, ie writing run {} for 3 Int will give you {-4, ... 3}. Many models only need the positive integers, so we'd get more state space coverage by allowing unsigned integers.

Example spec:

sig Resource {
  cost: Int
}

run {sum[univ.cost] <= 5} for 3 Int

This will give a lot of specs where Resources have negative costs, and there's no way for a Resource to cost 4.

[grayswandyr]

After discussion, it seems like a to complex task regarding the available developer manpower, while there exists a natural module.