Re: ISO/IEC DIS 8652 and ISO/IEC DIS 14519-1

[stt@spock.camb.inmet.com (Tucker Taft)]

In article <19940915.5134@naggum.no>, Erik Naggum  <erik@naggum.no> wrote:

> ...
>1003.5 is a binding to Ada 83 (ISO 8652:1987).  it is not unlikely that the
>second edition of ISO 8652 (Ada9X) will be published or at least approved
>for publication before voting on this standard terminates.

Actually, since Ada 9X is upward compatible with Ada 83,
1003.5 is also a binding to Ada 9X.

> ...
>PROBLEM
>
>I am in a difficult position, as I think most other SC 22 members and
>consultants are, whether I shall recommend to disapprove this DIS on
>grounds of impending revision of one of its base standard, or to proceed
>with the rubber-stamping procedure in the hopes that a revised version will
>eventually come along, and that an Ada 83 binding is more important than no
>binding.  that this is an IEEE standard already diminishes the importance
>of the latter point to near zero in my eyes.
>
>what does the Ada community think?  I am not in position to appreciate the
>consequences of either choice, and do not know whether this draft standard
>should be progressed, and would like to avoid an embarrassing mistake of
>helping to approve a standard that will be obsolete by the time its ink
>dries.

I believe you should support 1003.5.  Even though it was
designed with Ada 83 in mind, it is quite adequate for use
with Ada 9X, and will fill an important need that is just
as important with Ada 9X as with Ada 83, namely portable
access to Unix/Posix system calls.

>I do not understand why IEEE decides to fast-track this standard now that
>Ada is in the final stages of its revision, so if anybody knows this,
>please let me know.

There is no requirement to update every binding every time
a language is extended.  I am sure when and if new features
are added to C (e.g. the proposed numeric extensions), there 
will not be a sudden rush to revise every Posix/C binding
(or every other C binding).

In general, ISO standards that make references to other standards
implicitly refer to the latest revision of those standards --
here are words from the standard ISO "Normative References" prologue:

   "All standards are subject to revision, and parties to agreements
    based on this International Standard are encouraged to investigate
    the possibility of applying the most recent editions of the standards
    indicated below."

Presuming 1003.5 has similar wording, there should be no problem
using the Ada 9X standard in conjunction with 1003.5.
Upward compatibility allows essentially all Ada 83 bindings to
be used with Ada 9X.

>your advice is greatly appreciated.
>
>#<Erik>

S. Tucker Taft   stt@inmet.com
Ada 9X Mapping/Revision Team
Intermetrics, Inc.
Cambridge, MA  02138