[onox]

Sorry, but I disagree. Maybe in the 80s when developers were all yelling while coding :p Does this look like cobol to you?

   type GUID_String is new String (1 .. 32)
     with Dynamic_Predicate => (for all C of GUID_String => C in '0' .. '9' | 'a' .. 'f');

The only thing Ada has in common with cobol is that you can define decimal fixed point types (you specify the number of digits and a delta, which must be a power of 10) [1]

I usually use ordinary fixed point types:

   type Axis_Position is delta 2.0 ** (-15) range -1.0 .. 1.0 - 2.0 ** (-15)
     with Size => 16;

or (from wayland-ada [2]):

   type Fixed is delta 2.0 ** (-8) range -(2.0 ** 23) .. +(2.0 ** 23 - 1.0)
     with Small => 2.0 ** (-8),
          Size  => Integer'Size;

[1] https://en.wikibooks.org/wiki/Ada_Programming/Types/delta#Di... [2] https://github.com/onox/wayland-ada