Re: Static bounds of loop - compilation error

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Tue, 30 Oct 2012 17:10:54 +0100, Adam Beneschan <adam@irvine.com> a  
écrit:
>   case S(I) is
>
> or
>
>   case S'(I) is
>
> should make things work, because now the CASE expression has a nominal  
> subtype S, which is static, rather than "S range X .. Y", which isn't.
>
>                          -- Adam

That indeed solve the issue.

Note that you can also declare the type at the iteration variable too, a  
good practice, which is even mandatory with SPARK. Unfortunately, doing  
this, ends in a GNAT bug‑box:

     procedure T is
        type E is (A, B, C);
        subtype S is E range A .. B;
        X, Y : S;
     begin
        X := A;
        Y := B;
        for I : S in X .. Y loop
           case I is
              when A => null;
              when B => null;
           end case;
        end loop;
     end T;

-- 
“Syntactic sugar causes cancer of the semi-colons.” [1]
“Structured Programming supports the law of the excluded muddle.” [1]
[1]: Epigrams on Programming — Alan J. — P. Yale University