Re: type definition for an integer with discrete range

[Simon Wright <simon@pushface.org>]

tranngocduong@gmail.com writes:

> On Friday, March 29, 2019 at 11:10:42 PM UTC+7, mario.b...@gmail.com wrote:
>> Hello,
>> I'm looking for a way to define a type that runs from let say -100
>> to +100 with gaps of 5 width. Important is to make sure that a value
>> like 7 can not be assigned to the type.
>>
>> something like:
>>
>> type number is new integer range -100 .. 100;
>> -- or
>> subtype number is integer range -100 .. 100;
>>
>> -- with this special thing or something like that:
>> for number'small use 5; -- can not applied here. works with fixed
>> point types only
>>
>> Thanks !
>
> That's a fixed point type.

In Ada, that's an integer type. You can tell a real type because its
literals *must* have a decimal point in them. Fixed- and floating-point
types are both real types.

Mario's code might look like

  Number_Small : constant := 5.0;
  type Number is delta Number_Small range -100.0 .. 100.0;
  for Number'Small use Number_Small;