A question and a request

[Eric Merritt <cyberlync@yahoo.com>]

As some of you may know I am fairly new to Ada and I
just found out something that surprised me. I declared
two subtypes of an integer. I was then able to add
these two types together and assign the result to an
instance of one of the above subtypes. or

 subtype type_1 is Integer;
 subtype type_2 is Integer;
  
 type_1_instance   : type_1;
 type_2_instance   : type_2;
 type_1_instance_2 : type_1;

 type_1_instance   := 1;
 type_2_instance   := 2;
 type_1_instance_2 := type_1_instance +
type_2_instance;

The addition operator is taking two disparate but
related types and adding them. This is fine,
up-casting is a normal thing. However, when the result
is returned it is not (should not be?) an instance of
the subtype. It seems that the compiler is
down-casting automatically. This bothers me and it
seams that is violates Ada's strong typing. What am I
missing here?


My request is a bit simpler, is there any one out
there willing to serve as kind of a quasi-mentor.
Basically look at some simple code occasionally and
tell me when I am getting bad habits. I have found
when learning other languages without experienced
input that I am able to pick up the language in a few
weeks or months and then it takes me a couple of years
to realize I have bad habits and attempt to rectify
them. This shouldn't be too time consuming for the
volunteer. I have been programming in other languages
professionally (C/C++, Java, Perl and Python) and I
have a good understanding of the theory. I just need
someone to occasionally look and say "hey this is
stupid, in Ada do it this way" or "In Ada its better
to take this approach". I could post stuff to the list
but this seams to be poor etiquette. 

In any case, if I get an answer to my first question I
will be happy. Thanks



__________________________________________________
Do You Yahoo!?
Find a job, post your resume.
http://careers.yahoo.com