Re: type definition for an integer with discrete range

[tranngocduong@gmail.com]

On Friday, March 29, 2019 at 11:46:48 PM UTC+7, mario.b...@gmail.com wrote:
> On Friday, March 29, 2019 at 5:34:24 PM UTC+1, tranng...@gmail.com wrote:
> > 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.
> 
> It is about angles to be correct. The problem is that fixed types are rounded. I tried 
> 
> type type_angle is delta 90.0 range -359.9 .. 359.9; -- unit is degrees
> for type_angle'small use 90.0;
> 
> -- but it is possible to assign a value that is not a multiple of 90 degree and even outside the domain of type_angle:
> angle : type_angle := 370.0;
> 
> I want a constraint error being raised.

Actually, the domain is approximately [-450.0,+450.0], as pointed out by D. Kazakov.

If you need the domain closer to [-360.0,+360.0], use smaller number'small.