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From: Ken Garlington <kennieg@nospam.flash.net>
Subject: Re: Beware: Rep spec on an enumeration type causes code explosion
Date: 1997/12/10
Date: 1997-12-10T00:00:00+00:00	[thread overview]
Message-ID: <348F3DFC.10DB@nospam.flash.net> (raw)
In-Reply-To: EKxx9n.Ly1.0.-s@inmet.camb.inmet.com


Tucker Taft wrote:
> [big snip]
> I believe enumeration representation
> clauses in Ada are a mistake.  If a user wants to name
> particular values, they should simply use named integer
> constants, or perhaps better, named private-type constants.  They can build
> up various maps of their own if they want to translate to/from some kind
> of "holey" representation from/to a contiguous representation.

One of the nice things about "holey" representations in Ada, when used
for
interfacing to external systems, is the use of 'Valid to check for valid
input
data in a very readable manner. However, I would convert the raw input
to a non-holey type after the check, using either a map or case
statement
(depending upon the compiler).

> One "innocent" looking construct I once found was:
> 
>    (others => Default_Value(Segment))
> 
> used to initialize a segment of a load module to some default value.
> This called the function Default_Value once for each byte of the
> segment, and the segment was often 100K bytes or more.

Assuming the function's library unit was marked Pure, then this could
(and probably should) have been optimized, right? In this case, isn't
this more of a compiler issue than a language issue?

> -Tucker Taft   stt@inmet.com   http://www.inmet.com/~stt/
> Intermetrics, Inc.  Burlington, MA  USA




  parent reply	other threads:[~1997-12-10  0:00 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1997-12-05  0:00 Beware: Rep spec on an enumeration type causes code explosion Joe Gwinn
1997-12-06  0:00 ` Corey Minyard
1997-12-08  0:00   ` Joe Gwinn
1997-12-10  0:00     ` Robert Dewar
1997-12-06  0:00 ` Ken Garlington
1997-12-06  0:00 ` Robert Dewar
1997-12-08  0:00   ` Joe Gwinn
1997-12-09  0:00     ` Stanley R. Allen
1997-12-06  0:00 ` Robert Dewar
1997-12-06  0:00 ` Robert Dewar
1997-12-06  0:00 ` Robert Dewar
1997-12-08  0:00   ` Joe Gwinn
1997-12-06  0:00 ` Kevin D. Heatwole
     [not found]   ` <dewar.881478386@merv>
1997-12-07  0:00     ` Robert Dewar
1997-12-09  0:00   ` Jim Gleason
1997-12-06  0:00 ` Tucker Taft
1997-12-06  0:00   ` Robert Dewar
1997-12-06  0:00   ` Robert Dewar
1997-12-08  0:00   ` Joe Gwinn
1997-12-08  0:00     ` Mats Weber
1997-12-09  0:00     ` Geert Bosch
1997-12-10  0:00       ` Robert Dewar
1997-12-09  0:00     ` Tucker Taft
1997-12-09  0:00       ` Matthew Heaney
1997-12-10  0:00         ` Charles Hixson
1997-12-10  0:00       ` Jean-Pierre Rosen
1997-12-10  0:00       ` Robert Dewar
1997-12-10  0:00       ` Stanley R. Allen
1997-12-14  0:00         ` Robert Dewar
1997-12-10  0:00       ` Stephen Leake
1997-12-14  0:00         ` Robert Dewar
1997-12-10  0:00       ` Ken Garlington [this message]
1997-12-11  0:00         ` John G. Volan
1997-12-11  0:00           ` Ken Garlington
1997-12-12  0:00             ` Matthew Heaney
1997-12-12  0:00               ` Ken Garlington
1997-12-16  0:00                 ` John G. Volan
1997-12-17  0:00                   ` Ken Garlington
1997-12-12  0:00           ` Alan E & Carmel J Brain
1997-12-12  0:00             ` Robert Dewar
1997-12-15  0:00               ` Tucker Taft
1997-12-16  0:00                 ` Brian Rogoff
1997-12-12  0:00           ` Joe Gwinn
1997-12-12  0:00             ` Robert Dewar
1997-12-16  0:00             ` John G. Volan
1997-12-17  0:00               ` Joe Gwinn
1997-12-17  0:00                 ` John G. Volan
1997-12-18  0:00                   ` Joe Gwinn
1997-12-17  0:00               ` Ken Garlington
1997-12-11  0:00       ` Rakesh Malhotra
1997-12-11  0:00         ` Matthew Heaney
1997-12-12  0:00           ` Rakesh Malhotra
1997-12-12  0:00           ` Samuel Tardieu
1997-12-12  0:00             ` Robert Dewar
1997-12-12  0:00           ` Robert Dewar
1997-12-14  0:00         ` Alan E & Carmel J Brain
1997-12-12  0:00       ` Joe Gwinn
1997-12-15  0:00         ` Robert Dewar
1997-12-16  0:00           ` Joe Gwinn
1997-12-16  0:00             ` Robert Dewar
1997-12-06  0:00 ` David Marshall
1997-12-06  0:00 ` Robert Dewar
1997-12-06  0:00   ` Matthew Heaney
1997-12-10  0:00   ` GNORT information ( Was Re: Beware: Rep spec on an enumeration type causes code explosion ) Mark Bennison
1997-12-10  0:00     ` Robert Dewar
1997-12-07  0:00 ` Beware: Rep spec on an enumeration type causes code explosion Larry Kilgallen
  -- strict thread matches above, loose matches on Subject: below --
1997-12-09  0:00 tmoran
1997-12-11  0:00 Marin David Condic, 561.796.8997, M/S 731-96
1997-12-11  0:00 ` Robert Dewar
1997-12-11  0:00 Marin David Condic, 561.796.8997, M/S 731-96
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