Types, subtypes and ranges

["Anders Wirzenius" <anders.wirzenius@pp.qnet.fi>]

Mark Lundquist wrote in message ...
>Sorry for the late response (I lost access to news for a while...)
>
>WM <wwminirl@hotmail.com> wrote in message
>news:97pfmt$ll30@tech.port.ac.uk...
>> Hi, I am an ada beginner. Can anyone kindly tell me what's the difference
>> between TYPE and SUBTYPE?
>
...
>    subtype S is T;
>
>declares a new subtype S of the type of subtype T.  This is also an example
>of a subtype declaration that does not include a constraint, so the
>constraint of S is the same as the constraint of T.  (This is how you
>"rename" or create an alias for a type).  What a subtype declaration looks
>like that adds a constraint depends on the type of the subtypes, e.g. for
an
>integer type you might have

May I continue with two more questions:
1.
given
>
>    subtype S is T range 1 .. 10;

what is the the difference between the above declaration and
type S is new T range 1..10;

2.
Why don't I get a constraint_error in the following code where I violate the
range of type TTT in the Put statement?

with Ada.Text_IO;
procedure Why_Not_Constraint_Error is
   type T is new Integer;
   subtype TT is T range -2..-1;
   subtype TTT is T range -1..-1;
   anders : TT := -2;
   bnders : TTT := -1;
   use Ada.Text_IO;
begin
   Put ( TTT'Image ( anders+bnders ) );
end Why_Not_Constraint_Error;

Anders
another beginner