RE: Ada -vs- GNAT

["Robert C. Leif" <rleif@rleif.com>]

From: Bob Leif
To: Simon Wright et al.
The solution to the use of "img" is to make it standard Ada. The present
compiler vendors should implement "img".

-----Original Message-----
From: comp.lang.ada-admin@ada.eu.org
[mailto:comp.lang.ada-admin@ada.eu.org] On Behalf Of Simon Wright
Sent: Friday, May 24, 2002 9:22 PM
To: comp.lang.ada@ada.eu.org
Subject: Re: Ada -vs- GNAT

"Steve Doiel" <nospam_steved94@attbi.com> writes:

> I've been using Ada for a several years now.  In my opinion one of the
> greatest strengths of the language is in its portability.  I find it
> reassuring that different vendors distribute the same reference manual
for
> the language.

With a tailored version of Annex M.

> Recently I did some work with XML/Ada and found a few pieces code
dependent
> on the GNAT specific attributes 'img and 'unrestricted_access.  I was
able
> to make the code work with ObjectAda (and any other Ada compiler) by
making
> a few small changes to the sources.

Which seems a reasonable idea. I (hope I) have removed all "'Img"s
from the Booch Components, which are meant to be, and to a large
extent are, compiler-independent. On the other hand, given that GNAT
is my preferred compiler (for all sorts of reasons), I felt quite
happy to use 'Object_Size when appropriate.

> Personally I find the introduction of attributes and pragmas that are
not
> essential to be undesirable.
> 
> In a recent thread on the gcc mailing list, Robert Dewar describes how
ACT
> introduced the pragma "Unreferened" such that code that previously
appeared
> as:
> 
>   pragma Warnings (Off, entitiy)
> 
> could be replaced by
> 
>   pragma Unreferenced (entity)
> 
> because the latter is "neater, reads better, and is clearer why it is
> there."

Of course pragma Warnings is implementation-defined too.