Spec#, nullables and more

[bearophile]

Walter:

> Suppose, for example, you are appending the numbers 1..5 to the array, and 
> somehow appended a 17. Many moons later, something crashes because the 17 was 
> out of range.

This bug doesn't happen in Ada (and Delphi), because you define a ranged integer type like this:
subtype Small is Integer range 1 .. 5;

To see an example of this, look at this "useless" site where I have put a small Ada program that you may run yourself, with some stdin data:
http://ideone.com/shF5j

I try to put inside the "inputx" variable the following numbers:
1
2
1
4
17

But at runtime it gives:
raised CONSTRAINT_ERROR : prog.adb:9 range check failed

Bye,
bearophile