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From: Stephen Leake <Stephen.Leake@gsfc.nasa.gov>
Subject: Re: ada and robots
Date: 1997/06/20
Message-ID: <33AA8BFE.178A@gsfc.nasa.gov>#1/1
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References: <338CDA96.53EA@halcyon.com> <338F5D7D.6C03@tiac.net>
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Organization: NASA Goddard Space Flight Center -- Greenbelt, Maryland USA
Reply-To: Stephen.Leake@gsfc.nasa.gov
Newsgroups: comp.robotics.misc,comp.lang.ada
Date: 1997-06-20T00:00:00+00:00
List-Id: <comp.lang.ada>


Samuel Mize wrote:
> 
> Note that I make some comments about the person Mr. Whiting quoted,
> but none about Mr. Whiting.  Some quotations reformatted for length.
> 
> Stephen Leake wrote:
> >
> > Matthew S. Whiting wrote:
> >  ( second hand list of supposed Ada deficiencies )
> ...
> > > >*      Ada does not support discriminant unions (which are
> ...
> > This is precisely the Ada discriminant record:
> 
> Ah, but you can't hand-code the discriminant values.  This makes it
> harder to interface to existing C code, which of course makes C
> fundamentally better.
> 
Um, yes you can; that's what an enumeration representation clause is
for; see RM13.4

> Besides, you can't load the variable with one type and then read it
> as another type.  In C it's simple and safe, while in Ada it requires
> Unchecked_Conversion, which everyone knows is dangerous.

Um, this just means Ada _labels_ unchecked conversion as dangerous. In C
it may be "simple", but it is NOT "safe". (Maybe you forgot a smiley?)

> -- Samuel Mize    (817) 619-8622    smize@link.com    "Team Ada"
> -- Hughes Training Inc.  PO Box 6171 m/s 400, Arlington TX 76005

-- 
- Stephe