From: arny@wayback.UUCP (Arny B. Engelson)
Subject: Re: enumeration literal/internal codes query
Date: 31 Jan 89 18:05:05 GMT [thread overview]
Message-ID: <1504@wayback.UUCP> (raw)
In-Reply-To: 1105@shuksan.UUCP
In article <1105@shuksan.UUCP>, scott@shuksan.UUCP (Scott Moody) writes:
> In article <1438@trantor.harris-atd.com>, bbadger@x102c.uucp (Badger BA 64810) writes:
> > In article <1074@shuksan.UUCP> scott@shuksan.UUCP (Scott Moody) writes:
> > I've been wondering why you *want* to access the ``internal'' rep.
> > The standard use for rep clauses on enumeration types is to ``hide''
> > The only thing I've thought of is to use it as an ``external rep''
> > to be written to a file. Normally, of course, you would just instantiate
> > SEQUENTIAL_IO on the enumeration type, or on a record type with a component
> In my case, I am writing the internal representations
> of a lot of data structures to a file. Unfortunately
> there is no mixed_sequential_io so everything
> must be broken into a common data type (unsigned bytes in my case).
> Thus someone needs to make this conversion outside of the 'sequential_io'
> package. I supply a function to make this conversion which hides some
> of the burden.
> I agree that a sequential_io package would be nice, especially a mixed_io.
>
> -- scott
I think our local newsfeed lost Scott's original article (or I missed it).
But, since I originally raised this question, and never explained why I want
to know what the internal codes are, I thought I'd shed a little light.
We have a distributed application, targeted to a heterogeneous mixture
of processors which communicate by (among other things) sending a wide
variety of packetized messages over a serial link. Messages are also
created and sent to/from a host computer during debugging. These messages
are defined precisely (down to the bit). Some of the fields in these
messages are enumeration values that are defined in a common library package,
which is linked with application code on each of the processors. Groups of
messages are also created (as scenario test cases) on the host and stored in
a file.
Knowing the internal codes is helpful when these messages are created
(either by a processor or by a user attempting to debug the system), and
when these messages are interpreted. As you can see, mixed_sequential_io
isn't very useful.
This is just a partial description of the situation, but I hope I've
explained it sufficiently to at least gives an example of when this feature
would be useful. As soon as my current deadline crunch passes, I will put
together an Ada 9X revision request, so that the idea is at least (hopefully)
fully explored. Admittedly, as far as language deficiencies go, this is a
minor one (although assigning its importance a value from 1..10 seems very
subjective to me).
Thanks to all those who took the time to reply to my earlier request.
- Arny Engelson att!wayback!arny (201)386-4816
next prev parent reply other threads:[~1989-01-31 18:05 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
1989-01-09 15:25 enumeration literal/internal codes query Arny B. Engelson
1989-01-10 23:15 ` Arny B. Engelson
1989-01-13 17:03 ` Scott Moody
1989-01-16 18:03 ` Badger BA 64810
1989-01-19 19:44 ` Scott Moody
1989-01-31 18:05 ` Arny B. Engelson [this message]
1989-01-15 4:42 ` John Goodenough
1989-01-12 0:31 ` Michael Murphy
1989-01-12 15:51 ` enumeration literal/internal codes stt
1989-01-20 15:04 ` ryer
-- strict thread matches above, loose matches on Subject: below --
1989-01-13 21:29 enumeration literal/internal codes query rracine
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