I have always been interested in this area of programming. One thing I have always wanted is the ability to enforce restrictions on data types beyond memory. By that I mean say i am using an int, what if I want to restrict this to actually 1 -55 you can solve this using run time error handling but wouldnt it be better if we had static checks where upstream we could see an unbounded int being passed into this method and throw a compile error.
I think you could do that, but as long as you allow the usual operations on bounded variables (say, multiplication), you would have to ensure that the other operand is also bounded, or else you get an unbounded result nonetheless. Meaning, all variables that are used in any expression would have to be bounded eventually. There's also the problem that the compiler would have to infer that [1-10] - [1-2] can be negative, but does not have to. So with every expression on bounded variables, you increase their bounds' range, likely deleting the system's benefits.
I agree its super complex, these bounds wouldn't be limited to integer based variables. I would also argue there are very narrow instances where you would want to bound a variable and also do arithmetic on it. The language should make the bounding optional and unbounded possible.
