Re: JGNAT and Null references

[Tucker Taft <stt@averstar.com>]

Randy Brukardt wrote:
> 
> Marc A. Criley wrote in message <3AA151BF.C9193700@earthlink.net>...
> >Uh...it did work.  Cleared up the problem just fine.  That it works
> >doesn't totally sit well with me, since my purist mental picture of a
> >"constant" involves only a value, and not storage.  Nonetheless,
> >
> >   Null_Icon : constant Javax.swing.TabbedPanel.ref := null;
> >
> >was accepted by the AddTab procedure call.
> 
> But does it run? The RM  4.6(49) says that an access parameter cannot be
> null, and must raise Constraint_Error. If it does run, you're using a
> compiler bug (or "feature"); your code won't be portable...

There was discussion of avoiding the null check when interfacing
with code from some other language (e.g. C or Java).  Given that the
rules for making Java-convention calls are not standardized at
this point, so long as there is an explicit (or implicit?) Java
convention on the routines, JGNAT can do what it wants at this point.

> 
>         Randy.

-- 
-Tucker Taft   stt@avercom.net   http://www.averstar.com/~stt/
Chief Technology Officer, AverCom Corporation (A Titan Company) 
Burlington, MA  USA (AverCom was formerly the Commercial Division of AverStar:
http://www.averstar.com/services/ebusiness_applications.html)