From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: SI Units Checked and Unchecked
Date: Thu, 9 Aug 2018 16:07:21 +0200
Date: 2018-08-09T16:07:21+02:00 [thread overview]
Message-ID: <pkhhqo$4d8$1@gioia.aioe.org> (raw)
In-Reply-To: d628e94f-7ea0-4616-96a9-eb28ff6c9d6e@googlegroups.com
On 2018-08-09 15:47, Dan'l Miller wrote:
> Shouldn't the •entire• point of a units-of-measurement library (or feature of language) be compile-time errors, not run-time exceptions/errors.
No, because in most cases the unit is unknown. Consider a widget library
with instruments indicating dimensioned values, dimensioned calculator,
serialization of dimensioned data etc.
What is necessary but not sufficient is language support for handling
statically known constraints using compile-time static operations and
removing statically known discriminants from the representation.
Note a direct analogy with classes for scalar types. Type tag is in
essence just a discriminant. For some types we want static discriminants
and other constraints removed.
> I would be interested in a summary (or even better, an AI) that itemizes all the core-language obstacles in currently-standardized Ada to moving all the incompatible usages of units to be compile-time errors instead of raising exceptions.
The Ada type system is not capable to handle dimensioned types. I posted
a list of requirements for a dimensioned types support some years ago here.
There are lots of language issues to resolve first before approaching
dimensioned types.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2018-08-09 14:07 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-09 12:44 SI Units Checked and Unchecked AdaMagica
2018-08-09 13:47 ` Dan'l Miller
2018-08-09 14:07 ` Dmitry A. Kazakov [this message]
2018-08-09 15:03 ` Dan'l Miller
2018-08-09 15:51 ` Dmitry A. Kazakov
2018-08-09 17:32 ` Dan'l Miller
2018-08-09 19:42 ` Dmitry A. Kazakov
2018-08-09 22:12 ` Dan'l Miller
2018-08-10 6:45 ` Dmitry A. Kazakov
2018-08-10 13:59 ` Dan'l Miller
2018-08-10 14:50 ` Dmitry A. Kazakov
2018-08-10 17:04 ` Dan'l Miller
2018-08-10 17:34 ` Dmitry A. Kazakov
2018-08-11 4:42 ` Paul Rubin
2018-08-11 5:46 ` Dmitry A. Kazakov
2018-08-11 19:57 ` Paul Rubin
2018-08-11 21:01 ` Dmitry A. Kazakov
2018-08-09 18:47 ` Paul Rubin
2018-08-09 19:13 ` Dan'l Miller
2018-08-09 14:31 ` AdaMagica
2018-08-09 15:19 ` Dan'l Miller
2018-08-09 16:07 ` Jeffrey R. Carter
2018-08-09 17:41 ` AdaMagica
2018-08-09 20:34 ` Jeffrey R. Carter
2018-08-10 9:13 ` AdaMagica
2018-08-10 20:20 ` Jeffrey R. Carter
2018-08-13 8:57 ` AdaMagica
2018-08-20 17:55 ` AdaMagica
2019-09-04 14:20 ` Shark8
2019-09-04 17:11 ` AdaMagica
2019-09-06 21:01 ` Shark8
2020-08-13 12:24 ` SI Units Checked and Unchecked - Completela overhauled version AdaMagica
-- strict thread matches above, loose matches on Subject: below --
2003-02-05 7:03 SI Units Checked and Unchecked Grein, Christoph
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